use serde_json::{json, Value};
use once_cell::sync::Lazy;
use super::tool_adapter::ToolAdapter;
use super::tool_adapters::PencilAdapter;

/// 不被 Gemini 支持但包含重要语义信息的约束字段
/// 这些字段将在删除前被转化为 description 提示
const CONSTRAINT_FIELDS: &[(&str, &str)] = &[
    ("minLength", "minLen"),
    ("maxLength", "maxLen"),
    ("pattern", "pattern"),
    ("minimum", "min"),
    ("maximum", "max"),
    ("multipleOf", "multipleOf"),
    ("exclusiveMinimum", "exclMin"),
    ("exclusiveMaximum", "exclMax"),
    ("minItems", "minItems"),
    ("maxItems", "maxItems"),
    ("format", "format"),
];

/// 全局工具适配器注册表
/// 
/// 所有注册的适配器都会在 Schema 清洗时被检查和应用
static TOOL_ADAPTERS: Lazy<Vec<Box<dyn ToolAdapter>>> = Lazy::new(|| {
    vec![
        Box::new(PencilAdapter),
        // 未来可以轻松添加更多适配器:
        // Box::new(FilesystemAdapter),
        // Box::new(DatabaseAdapter),
    ]
});

const MAX_RECURSION_DEPTH: usize = 10;

/// 递归清理 JSON Schema 以符合 Gemini 接口要求
///
/// 1. [New] 展开 $ref 和 $defs: 将引用替换为实际定义，解决 Gemini 不支持 $ref 的问题
/// 2. 移除不支持的字段: $schema, additionalProperties, format, default, uniqueItems, validation fields
/// 3. 处理联合类型: ["string", "null"] -> "string"
/// 4. [NEW] 处理 anyOf 联合类型: anyOf: [{"type": "string"}, {"type": "null"}] -> "type": "string"
/// 5. 将 type 字段的值转换为小写 (Gemini v1internal 要求)
/// 6. 移除数字校验字段: multipleOf, exclusiveMinimum, exclusiveMaximum 等
pub fn clean_json_schema(value: &mut Value) {
    // 0. 预处理：展开 $ref (Schema Flattening)
    // [FIX #952] 递归收集所有层级的 $defs/definitions，而非仅从根层级提取
    let mut all_defs = serde_json::Map::new();
    collect_all_defs(value, &mut all_defs);

    // 移除根层级的 $defs/definitions (保持向后兼容)
    if let Value::Object(map) = value {
        map.remove("$defs");
        map.remove("definitions");
    }

    // [FIX #952] 始终运行 flatten_refs，即使 defs 为空
    // 这样可以捕获并处理无法解析的 $ref (降级为 string 类型)
    if let Value::Object(map) = value {
        flatten_refs(map, &all_defs, 0);
    }

    // 递归清理
    clean_json_schema_recursive(value, true, 0);
}

/// 带工具适配器支持的 Schema 清洗
/// 
/// 这是推荐的清洗入口,支持工具特定的优化
/// 
/// # Arguments
/// * `value` - 待清洗的 JSON Schema
/// * `tool_name` - 工具名称,用于匹配适配器
/// 
/// # 处理流程
/// 1. 查找匹配的工具适配器
/// 2. 执行适配器的预处理 (工具特定优化)
/// 3. 执行通用清洗逻辑
/// 4. 执行适配器的后处理 (最终调整)
pub fn clean_json_schema_for_tool(value: &mut Value, tool_name: &str) {
    // 1. 查找匹配的适配器
    let adapter = TOOL_ADAPTERS.iter()
        .find(|a| a.matches(tool_name));
    
    // 2. 执行预处理
    if let Some(adapter) = adapter {
        let _ = adapter.pre_process(value);
    }
    
    // 3. 执行通用清洗
    clean_json_schema(value);
    
    // 4. 执行后处理
    if let Some(adapter) = adapter {
        let _ = adapter.post_process(value);
    }
}

/// [NEW #952] 递归收集所有层级的 $defs 和 definitions
///
/// MCP 工具的 schema 可能在任意嵌套层级定义 $defs，而非仅在根层级。
/// 此函数深度遍历整个 schema，收集所有定义到统一的 map 中。
fn collect_all_defs(value: &Value, defs: &mut serde_json::Map<String, Value>) {
    if let Value::Object(map) = value {
        // 收集当前层级的 $defs
        if let Some(Value::Object(d)) = map.get("$defs") {
            for (k, v) in d {
                // 避免覆盖已存在的定义（先定义的优先）
                defs.entry(k.clone()).or_insert_with(|| v.clone());
            }
        }
        // 收集当前层级的 definitions (Draft-07 风格)
        if let Some(Value::Object(d)) = map.get("definitions") {
            for (k, v) in d {
                defs.entry(k.clone()).or_insert_with(|| v.clone());
            }
        }
        // 递归处理所有子节点
        for (key, v) in map {
            // 跳过 $defs/definitions 本身，避免重复处理
            if key != "$defs" && key != "definitions" {
                collect_all_defs(v, defs);
            }
        }
    } else if let Value::Array(arr) = value {
        for item in arr {
            collect_all_defs(item, defs);
        }
    }
}

/// 递归展开 $ref
fn flatten_refs(
    map: &mut serde_json::Map<String, Value>,
    defs: &serde_json::Map<String, Value>,
    depth: usize,
) {
    if depth > MAX_RECURSION_DEPTH {
        tracing::warn!("[Schema-Flatten] Max recursion depth reached, stopping ref expansion.");
        return;
    }

    // 检查并替换 $ref
    if let Some(Value::String(ref_path)) = map.remove("$ref") {
        // 解析引用名 (例如 #/$defs/MyType -> MyType)
        let ref_name = ref_path.split('/').last().unwrap_or(&ref_path);

        if let Some(def_schema) = defs.get(ref_name) {
            // 将定义的内容合并到当前 map
            if let Value::Object(def_map) = def_schema {
                for (k, v) in def_map {
                    // 仅当当前 map 没有该 key 时才插入 (避免覆盖)
                    // 但通常 $ref 节点不应该有其他属性
                    map.entry(k.clone()).or_insert_with(|| v.clone());
                }

                // 递归处理刚刚合并进来的内容中可能包含的 $ref
                // 注意：由于引入了 depth 限制，循环引用不再会导致栈溢出
                flatten_refs(map, defs, depth + 1);
            }
        } else {
            // [FIX #952] 无法解析的 $ref: 转换为宽松的 string 类型，避免 API 400 错误
            // 这比让请求失败要好，至少工具调用仍可进行
            map.insert("type".to_string(), serde_json::json!("string"));
            let hint = format!("(Unresolved $ref: {})", ref_path);
            let desc_val = map
                .entry("description".to_string())
                .or_insert_with(|| Value::String(String::new()));
            if let Value::String(s) = desc_val {
                if !s.contains(&hint) {
                    if !s.is_empty() {
                        s.push(' ');
                    }
                    s.push_str(&hint);
                }
            }
        }
    }

    // 遍历子节点
    for (_, v) in map.iter_mut() {
        if let Value::Object(child_map) = v {
            flatten_refs(child_map, defs, depth + 1);
        } else if let Value::Array(arr) = v {
            for item in arr {
                if let Value::Object(item_map) = item {
                    flatten_refs(item_map, defs, depth + 1);
                }
            }
        }
    }
}

fn clean_json_schema_recursive(value: &mut Value, is_schema_node: bool, depth: usize) -> bool {
    if depth > MAX_RECURSION_DEPTH {
        debug_assert!(false, "Max recursion depth reached in clean_json_schema_recursive");
        return false;
    }
    let mut is_effectively_nullable = false;

    match value {
        Value::Object(map) => {
            // 0. [NEW] 合并 allOf
            merge_all_of(map);

            // 0.5 [NEW] 结构归一化 (Normalization)
            // 针对某些 MCP 工具（如 pencil）误用 items 定义对象属性的情况进行修复。
            // 如果 type=object 或包含 properties，但又定义了 items，Gemini 会因为 items 只能出现在 array 中而报错。
            // 我们将 items 的内容“对齐”到 properties 中。
            if map.get("type").and_then(|t| t.as_str()) == Some("object") || map.contains_key("properties") {
                if let Some(items) = map.remove("items") {
                    tracing::warn!("[Schema-Normalization] Found 'items' in an Object-like node. Moving content to 'properties'.");
                    let target_props = map.entry("properties".to_string()).or_insert_with(|| json!({}));
                    if let Some(target_map) = target_props.as_object_mut() {
                        if let Some(source_map) = items.as_object() {
                            for (k, v) in source_map {
                                target_map.entry(k.clone()).or_insert_with(|| v.clone());
                            }
                        }
                    }
                }
            }

            // 1. [CRITICAL] 深度递归处理子项
            // 处理 properties (对象)
            if let Some(Value::Object(props)) = map.get_mut("properties") {
                let mut nullable_keys = std::collections::HashSet::new();
                for (k, v) in props {
                    // properties 的每一个值都必须是一个独立的 Schema 节点
                    if clean_json_schema_recursive(v, true, depth + 1) {
                        nullable_keys.insert(k.clone());
                    }
                }

                if !nullable_keys.is_empty() {
                    if let Some(Value::Array(req_arr)) = map.get_mut("required") {
                        req_arr.retain(|r| {
                            r.as_str()
                                .map(|s| !nullable_keys.contains(s))
                                .unwrap_or(true)
                        });
                        if req_arr.is_empty() {
                            map.remove("required");
                        }
                    }
                }

                // [NEW] 隐式类型注入：如果有 properties 但没 type，补全为 object
                if !map.contains_key("type") {
                    map.insert("type".to_string(), Value::String("object".to_string()));
                }
            }
            
            // 处理 items (数组)
            if let Some(items) = map.get_mut("items") {
                // items 的内容必须是一个独立的 Schema 节点
                clean_json_schema_recursive(items, true, depth + 1);

                // [NEW] 隐式类型注入：如果有 items 但没 type，补全为 array
                if !map.contains_key("type") {
                    map.insert("type".to_string(), Value::String("array".to_string()));
                }
            }

            // Fallback: 对既没有 properties 也没有 items 的常规对象进行清理
            if !map.contains_key("properties") && !map.contains_key("items") {
                for (k, v) in map.iter_mut() {
                    // 排除掉关键字
                    if k != "anyOf" && k != "oneOf" && k != "allOf" && k != "enum" && k != "type" {
                        clean_json_schema_recursive(v, false, depth + 1);
                    }
                }
            }

            // 1.5. [FIX] 递归清理 anyOf/oneOf 数组中的每个分支
            // 必须在合并逻辑之前执行，确保合并的分支已经被清洗
            if let Some(Value::Array(any_of)) = map.get_mut("anyOf") {
                for branch in any_of.iter_mut() {
                    clean_json_schema_recursive(branch, true, depth + 1);
                }
            }
            if let Some(Value::Array(one_of)) = map.get_mut("oneOf") {
                for branch in one_of.iter_mut() {
                    clean_json_schema_recursive(branch, true, depth + 1);
                }
            }

            // 2. [FIX #815] 处理 anyOf/oneOf 联合类型: 合并属性或择优选择分支
            let mut union_to_merge = None;
            if let Some(Value::Array(any_of)) = map.get("anyOf") {
                union_to_merge = Some(any_of.clone());
            } else if let Some(Value::Array(one_of)) = map.get("oneOf") {
                union_to_merge = Some(one_of.clone());
            }

            if let Some(union_array) = union_to_merge {
                if let Some((best_branch, all_types)) = extract_best_schema_from_union(&union_array) {
                    if let Value::Object(branch_obj) = best_branch {
                        // 合并分支属性到当前 map
                        for (k, v) in branch_obj {
                            if k == "properties" {
                                if let Some(target_props) = map
                                    .entry("properties".to_string())
                                    .or_insert_with(|| Value::Object(serde_json::Map::new()))
                                    .as_object_mut()
                                {
                                    if let Some(source_props) = v.as_object() {
                                        for (pk, pv) in source_props {
                                            target_props
                                                .entry(pk.clone())
                                                .or_insert_with(|| pv.clone());
                                        }
                                    }
                                }
                            } else if k == "required" {
                                if let Some(target_req) = map
                                    .entry("required".to_string())
                                    .or_insert_with(|| Value::Array(Vec::new()))
                                    .as_array_mut()
                                {
                                    if let Some(source_req) = v.as_array() {
                                        for rv in source_req {
                                            if !target_req.contains(rv) {
                                                target_req.push(rv.clone());
                                            }
                                        }
                                    }
                                }
                            } else if !map.contains_key(&k) {
                                map.insert(k, v);
                            }
                        }
                    }
                    
                    // [NEW] 添加类型提示到描述中 (参考 CLIProxyAPI)
                    if all_types.len() > 1 {
                        let type_hint = format!("Accepts: {}", all_types.join(" | "));
                        append_hint_to_description(map, type_hint);
                    }
                }
            }

            // 3. [SAFETY] 检查当前对象是否为 JSON Schema 节点
            // 只有当对象看起来像 Schema (包含 type, properties, items, enum, anyOf 等) 时，才执行白名单过滤。
            // 否则，如果它是一个普通的 Value (如 request.rs 中的 functionCall 对象)，直接应用激进过滤会破坏结构。
            let allowed_fields = [
                "type",
                "description",
                "properties",
                "required",
                "items",
                "enum",
                "title",
            ];
            
            let has_standard_keyword = map.keys().any(|k| allowed_fields.contains(&k.as_str()));

            // [NEW] 启发式修复：如果明确是 Schema 节点，但没有标准关键字，却有其他 Key
            // 我们推测这是一个“简写”的对象定义，尝试将其内部 Key 移动到 properties 中。
            // 补充：必须确保它不是工具调用或结果 (含有 functionCall/functionResponse)，防止结构被破坏。
            let is_not_schema_payload = map.contains_key("functionCall") || map.contains_key("functionResponse");
            if is_schema_node && !has_standard_keyword && !map.is_empty() && !is_not_schema_payload {
                let mut properties = serde_json::Map::new();
                let keys: Vec<String> = map.keys().cloned().collect();
                for k in keys {
                    if let Some(v) = map.remove(&k) {
                        properties.insert(k, v);
                    }
                }
                map.insert("type".to_string(), Value::String("object".to_string()));
                map.insert("properties".to_string(), Value::Object(properties));
                
                // 递归清理刚刚移动进去的属性
                if let Some(Value::Object(props_map)) = map.get_mut("properties") {
                    for v in props_map.values_mut() {
                        clean_json_schema_recursive(v, true, depth + 1); 
                    }
                }
            }

            let looks_like_schema = (is_schema_node || has_standard_keyword) && !is_not_schema_payload;

            if looks_like_schema {
                // 4. [ROBUST] 约束迁移：在被白名单过滤前，将校验项转为描述 Hint
                // [NEW] 使用统一的约束回填函数
                move_constraints_to_description(map);

                // 5. [CRITICAL] 白名单过滤：彻底物理移除 Gemini 不支持的内容，防止 400 错误
                let keys_to_remove: Vec<String> = map
                    .keys()
                    .filter(|k| !allowed_fields.contains(&k.as_str()))
                    .cloned()
                    .collect();
                for k in keys_to_remove {
                    map.remove(&k);
                }

                // 6. [SAFETY] 处理空 Object
                // [FIX] 移除 reason 字段注入逻辑
                // 之前的实现会为空 Object 注入 reason 字段，导致 Gemini CLI 等工具报 "malformed function call"
                // 因为模型会生成包含 reason 参数的调用，但工具定义中并没有这个参数
                // 现在改为：空 Object 保持空的 properties，让 Gemini 模型自行决定是否需要参数
                if map.get("type").and_then(|t| t.as_str()) == Some("object") {
                    if !map.contains_key("properties") {
                        map.insert("properties".to_string(), serde_json::json!({}));
                    }
                }

                // 7. [SAFETY] Required 字段对齐
                let valid_prop_keys: Option<std::collections::HashSet<String>> = map
                    .get("properties")
                    .and_then(|p| p.as_object())
                    .map(|obj| obj.keys().cloned().collect());

                if let Some(required_val) = map.get_mut("required") {
                    if let Some(req_arr) = required_val.as_array_mut() {
                        if let Some(keys) = &valid_prop_keys {
                            req_arr
                                .retain(|k| k.as_str().map(|s| keys.contains(s)).unwrap_or(false));
                        } else {
                            req_arr.clear();
                        }
                    }
                }

                if !map.contains_key("type") {
                    if map.contains_key("enum") {
                        map.insert("type".to_string(), Value::String("string".to_string()));
                    } else if map.contains_key("properties") {
                        map.insert("type".to_string(), Value::String("object".to_string()));
                    } else if map.contains_key("items") {
                        map.insert("type".to_string(), Value::String("array".to_string()));
                    }
                }

                // [IMPROVED] 提前计算回退类型以避免借用冲突
                let fallback = if map.contains_key("properties") {
                    "object"
                } else if map.contains_key("items") {
                    "array"
                } else {
                    "string"
                };

                // 8. 处理 type 字段
                if let Some(type_val) = map.get_mut("type") {
                    let mut selected_type = None;
                    match type_val {
                        Value::String(s) => {
                            let lower = s.to_lowercase();
                            if lower == "null" {
                                is_effectively_nullable = true;
                            } else {
                                selected_type = Some(lower);
                            }
                        }
                        Value::Array(arr) => {
                            for item in arr {
                                if let Value::String(s) = item {
                                    let lower = s.to_lowercase();
                                    if lower == "null" {
                                        is_effectively_nullable = true;
                                    } else if selected_type.is_none() {
                                        selected_type = Some(lower);
                                    }
                                }
                            }
                        }
                        _ => {}
                    }
                    
                    *type_val =
                        Value::String(selected_type.unwrap_or_else(|| fallback.to_string()));
                }

                if is_effectively_nullable {
                    let desc_val = map
                        .entry("description".to_string())
                        .or_insert_with(|| Value::String("".to_string()));
                    if let Value::String(s) = desc_val {
                        if !s.contains("nullable") {
                            if !s.is_empty() {
                                s.push(' ');
                            }
                            s.push_str("(nullable)");
                        }
                    }
                }

                // 9. Enum 值强制转字符串
                if let Some(Value::Array(arr)) = map.get_mut("enum") {
                    for item in arr {
                        if !item.is_string() {
                            *item = Value::String(if item.is_null() {
                                "null".to_string()
                            } else {
                                item.to_string()
                            });
                        }
                    }
                }
            }
        }
        Value::Array(arr) => {
            // [FIX] 递归清理数组中的每个元素
            // 这确保了所有数组类型的值（包括但不限于 anyOf、oneOf、items、enum 等）都会被递归处理
            for item in arr.iter_mut() {
                clean_json_schema_recursive(item, is_schema_node, depth + 1);
            }
        }
        _ => {}
    }

    is_effectively_nullable
}

/// [NEW] 合并 allOf 数组中的所有子 Schema
fn merge_all_of(map: &mut serde_json::Map<String, Value>) {
    if let Some(Value::Array(all_of)) = map.remove("allOf") {
        let mut merged_properties = serde_json::Map::new();
        let mut merged_required = std::collections::HashSet::new();
        let mut other_fields = serde_json::Map::new();

        for sub_schema in all_of {
            if let Value::Object(sub_map) = sub_schema {
                // 合并属性
                if let Some(Value::Object(props)) = sub_map.get("properties") {
                    for (k, v) in props {
                        merged_properties.insert(k.clone(), v.clone());
                    }
                }

                // 合并 required
                if let Some(Value::Array(reqs)) = sub_map.get("required") {
                    for req in reqs {
                        if let Some(s) = req.as_str() {
                            merged_required.insert(s.to_string());
                        }
                    }
                }

                // 合并其余字段 (第一个出现的胜出)
                for (k, v) in sub_map {
                    if k != "properties"
                        && k != "required"
                        && k != "allOf"
                        && !other_fields.contains_key(&k)
                    {
                        other_fields.insert(k, v);
                    }
                }
            }
        }

        // 应用合并后的字段
        for (k, v) in other_fields {
            if !map.contains_key(&k) {
                map.insert(k, v);
            }
        }

        if !merged_properties.is_empty() {
            let existing_props = map
                .entry("properties".to_string())
                .or_insert_with(|| Value::Object(serde_json::Map::new()));
            if let Value::Object(existing_map) = existing_props {
                for (k, v) in merged_properties {
                    existing_map.entry(k).or_insert(v);
                }
            }
        }

        if !merged_required.is_empty() {
            let existing_reqs = map
                .entry("required".to_string())
                .or_insert_with(|| Value::Array(Vec::new()));
            if let Value::Array(req_arr) = existing_reqs {
                let mut current_reqs: std::collections::HashSet<String> = req_arr
                    .iter()
                    .filter_map(|v| v.as_str().map(|s| s.to_string()))
                    .collect();
                for req in merged_required {
                    if current_reqs.insert(req.clone()) {
                        req_arr.push(Value::String(req));
                    }
                }
            }
        }
    }
}

/// [NEW] 将提示信息追加到 description 字段
/// 参考 CLIProxyAPI 的 Lazy Hint 策略
fn append_hint_to_description(map: &mut serde_json::Map<String, Value>, hint: String) {
    let desc_val = map
        .entry("description".to_string())
        .or_insert_with(|| Value::String("".to_string()));
    
    if let Value::String(s) = desc_val {
        if s.is_empty() {
            *s = hint;
        } else if !s.contains(&hint) {
            *s = format!("{} {}", s, hint);
        }
    }
}

/// [NEW] 将约束字段转化为 description 提示
/// 在删除约束字段前,将其语义信息保留在描述中,让模型能够理解约束
fn move_constraints_to_description(map: &mut serde_json::Map<String, Value>) {
    let mut hints = Vec::new();
    
    for (field, label) in CONSTRAINT_FIELDS {
        if let Some(val) = map.get(*field) {
            if !val.is_null() {
                let val_str = if let Some(s) = val.as_str() {
                    s.to_string()
                } else {
                    val.to_string()
                };
                hints.push(format!("{}: {}", label, val_str));
            }
        }
    }
    
    if !hints.is_empty() {
        let constraint_hint = format!("[Constraint: {}]", hints.join(", "));
        append_hint_to_description(map, constraint_hint);
    }
}

/// [NEW] 计算 Schema 分支的复杂度得分 (用于 anyOf/oneOf 择优)
/// 评分标准: Object (3) > Array (2) > Scalar (1) > Null (0)
fn score_schema_option(val: &Value) -> i32 {
    if let Value::Object(obj) = val {
        if obj.contains_key("properties")
            || obj.get("type").and_then(|t| t.as_str()) == Some("object")
        {
            return 3;
        }
        if obj.contains_key("items") || obj.get("type").and_then(|t| t.as_str()) == Some("array") {
            return 2;
        }
        if let Some(type_str) = obj.get("type").and_then(|t| t.as_str()) {
            if type_str != "null" {
                return 1;
            }
        }
    }
    0
}


/// [NEW] 从 anyOf/oneOf 联合类型数组中选取最佳非 null Schema 分支
/// 返回: (最佳Schema, 所有可能的类型列表)
/// 参考 CLIProxyAPI 的 selectBest 逻辑
fn extract_best_schema_from_union(union_array: &Vec<Value>) -> Option<(Value, Vec<String>)> {
    let mut best_option: Option<&Value> = None;
    let mut best_score = -1;
    let mut all_types = Vec::new();

    for item in union_array {
        let score = score_schema_option(item);
        
        // 收集类型信息
        if let Some(type_str) = get_schema_type_name(item) {
            if !all_types.contains(&type_str) {
                all_types.push(type_str);
            }
        }
        
        if score > best_score {
            best_score = score;
            best_option = Some(item);
        }
    }

    best_option.cloned().map(|schema| (schema, all_types))
}

/// [NEW] 获取 Schema 的类型名称
fn get_schema_type_name(schema: &Value) -> Option<String> {
    if let Value::Object(obj) = schema {
        // 优先使用显式的 type 字段
        if let Some(type_val) = obj.get("type") {
            if let Some(s) = type_val.as_str() {
                return Some(s.to_string());
            }
        }
        
        // 根据结构推断类型
        if obj.contains_key("properties") {
            return Some("object".to_string());
        }
        if obj.contains_key("items") {
            return Some("array".to_string());
        }
    }
    
    None
}

/// 修正工具调用参数的类型，使其符合 schema 定义
///
/// 根据 schema 中的 type 定义，自动转换参数值的类型：
/// - "123" → 123 (string → number/integer)
/// - "true" → true (string → boolean)
/// - 123 → "123" (number → string)
///
/// # Arguments
/// * `args` - 工具调用的参数对象 (会被原地修改)
/// * `schema` - 工具的参数 schema 定义 (通常是 parameters 对象)
pub fn fix_tool_call_args(args: &mut Value, schema: &Value) {
    if let Some(properties) = schema.get("properties").and_then(|p| p.as_object()) {
        if let Some(args_obj) = args.as_object_mut() {
            for (key, value) in args_obj.iter_mut() {
                if let Some(prop_schema) = properties.get(key) {
                    fix_single_arg_recursive(value, prop_schema);
                }
            }
        }
    }
}

/// 递归修正单个参数的类型
fn fix_single_arg_recursive(value: &mut Value, schema: &Value) {
    // 1. 处理嵌套对象 (properties)
    if let Some(nested_props) = schema.get("properties").and_then(|p| p.as_object()) {
        if let Some(value_obj) = value.as_object_mut() {
            for (key, nested_value) in value_obj.iter_mut() {
                if let Some(nested_schema) = nested_props.get(key) {
                    fix_single_arg_recursive(nested_value, nested_schema);
                }
            }
        }
        return;
    }

    // 2. 处理数组 (items)
    let schema_type = schema
        .get("type")
        .and_then(|t| t.as_str())
        .unwrap_or("")
        .to_lowercase();
    if schema_type == "array" {
        if let Some(items_schema) = schema.get("items") {
            if let Some(arr) = value.as_array_mut() {
                for item in arr {
                    fix_single_arg_recursive(item, items_schema);
                }
            }
        }
        return;
    }

    // 3. 处理基础类型修正
    match schema_type.as_str() {
        "number" | "integer" => {
            // 字符串 → 数字
            if let Some(s) = value.as_str() {
                // [SAFETY] 保护具有前导零的版本号或代码 (如 "01", "007")，不应转为数字
                if s.starts_with('0') && s.len() > 1 && !s.starts_with("0.") {
                    return;
                }

                // 优先尝试解析为整数
                if let Ok(i) = s.parse::<i64>() {
                    *value = Value::Number(serde_json::Number::from(i));
                } else if let Ok(f) = s.parse::<f64>() {
                    if let Some(n) = serde_json::Number::from_f64(f) {
                        *value = Value::Number(n);
                    }
                }
            }
        }
        "boolean" => {
            // 字符串 → 布尔
            if let Some(s) = value.as_str() {
                match s.to_lowercase().as_str() {
                    "true" | "1" | "yes" | "on" => *value = Value::Bool(true),
                    "false" | "0" | "no" | "off" => *value = Value::Bool(false),
                    _ => {}
                }
            } else if let Some(n) = value.as_i64() {
                // 数字 1/0 -> 布尔
                if n == 1 {
                    *value = Value::Bool(true);
                } else if n == 0 {
                    *value = Value::Bool(false);
                }
            }
        }
        "string" => {
            // 非字符串 → 字符串 (防止客户端误传数字给文本字段)
            if !value.is_string() && !value.is_null() && !value.is_object() && !value.is_array() {
                *value = Value::String(value.to_string());
            }
        }
        _ => {}
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use serde_json::json;

    #[test]
    fn test_clean_json_schema_draft_2020_12() {
        let mut schema = json!({
            "$schema": "http://json-schema.org/draft-07/schema#",
            "type": "object",
            "properties": {
                "location": {
                    "type": "string",
                    "minLength": 1,
                    "format": "city"
                },
                // 模拟属性名冲突：pattern 是一个 Object 属性，不应被移除
                "pattern": {
                    "type": "object",
                    "properties": {
                        "regex": { "type": "string", "pattern": "^[a-z]+$" }
                    }
                },
                "unit": {
                    "type": ["string", "null"],
                    "default": "celsius"
                }
            },
            "required": ["location"]
        });

        clean_json_schema(&mut schema);

        // 1. 验证类型保持小写
        assert_eq!(schema["type"], "object");
        assert_eq!(schema["properties"]["location"]["type"], "string");

        // 2. 验证标准字段被移除并转为描述 (Robust Constraint Migration)
        assert!(schema["properties"]["location"].get("minLength").is_none());
        assert!(schema["properties"]["location"].get("format").is_none());
        assert!(schema["properties"]["location"]["description"]
            .as_str()
            .unwrap()
            .contains("[Constraint: minLen: 1, format: city]"));

        // 3. 验证名为 "pattern" 的属性未被误删
        assert!(schema["properties"].get("pattern").is_some());
        assert_eq!(schema["properties"]["pattern"]["type"], "object");

        // 4. 验证内部的 pattern 校验字段被移除并转为描述
        assert!(schema["properties"]["pattern"]["properties"]["regex"]
            .get("pattern")
            .is_none());
        assert!(
            schema["properties"]["pattern"]["properties"]["regex"]["description"]
                .as_str()
                .unwrap()
                .contains("[Constraint: pattern: ^[a-z]+$]")
        );

        // 5. 验证联合类型被降级为单一类型 (Protobuf 兼容性)
        assert_eq!(schema["properties"]["unit"]["type"], "string");

        // 6. 验证元数据字段被移除
        assert!(schema.get("$schema").is_none());
    }

    #[test]
    fn test_type_fallback() {
        // Test ["string", "null"] -> "string"
        let mut s1 = json!({"type": ["string", "null"]});
        clean_json_schema(&mut s1);
        assert_eq!(s1["type"], "string");

        // Test ["integer", "null"] -> "integer" (and lowercase check if needed, though usually integer)
        let mut s2 = json!({"type": ["integer", "null"]});
        clean_json_schema(&mut s2);
        assert_eq!(s2["type"], "integer");
    }

    #[test]
    fn test_flatten_refs() {
        let mut schema = json!({
            "$defs": {
                "Address": {
                    "type": "object",
                    "properties": {
                        "city": { "type": "string" }
                    }
                }
            },
            "properties": {
                "home": { "$ref": "#/$defs/Address" }
            }
        });

        clean_json_schema(&mut schema);

        // 验证引用被展开且类型转为小写
        assert_eq!(schema["properties"]["home"]["type"], "object");
        assert_eq!(
            schema["properties"]["home"]["properties"]["city"]["type"],
            "string"
        );
    }

    #[test]
    fn test_clean_json_schema_missing_required() {
        let mut schema = json!({
            "type": "object",
            "properties": {
                "existing_prop": { "type": "string" }
            },
            "required": ["existing_prop", "missing_prop"]
        });

        clean_json_schema(&mut schema);

        // 验证 missing_prop 被从 required 中移除
        let required = schema["required"].as_array().unwrap();
        assert_eq!(required.len(), 1);
        assert_eq!(required[0].as_str().unwrap(), "existing_prop");
    }

    // [NEW TEST] 验证 anyOf 类型提取
    #[test]
    fn test_anyof_type_extraction() {
        // 测试 FastMCP 风格的 Optional[str] schema
        let mut schema = json!({
            "type": "object",
            "properties": {
                "testo": {
                    "anyOf": [
                        {"type": "string"},
                        {"type": "null"}
                    ],
                    "default": null,
                    "title": "Testo"
                },
                "importo": {
                    "anyOf": [
                        {"type": "number"},
                        {"type": "null"}
                    ],
                    "default": null,
                    "title": "Importo"
                },
                "attivo": {
                    "type": "boolean",
                    "title": "Attivo"
                }
            }
        });

        clean_json_schema(&mut schema);

        // 验证 anyOf 被移除
        assert!(schema["properties"]["testo"].get("anyOf").is_none());
        assert!(schema["properties"]["importo"].get("anyOf").is_none());

        // 验证 type 被正确提取
        assert_eq!(schema["properties"]["testo"]["type"], "string");
        assert_eq!(schema["properties"]["importo"]["type"], "number");
        assert_eq!(schema["properties"]["attivo"]["type"], "boolean");

        // 验证 default 被移除 (白名单之外)
        assert!(schema["properties"]["testo"].get("default").is_none());
    }

    // [NEW TEST] 验证 oneOf 类型提取
    #[test]
    fn test_oneof_type_extraction() {
        let mut schema = json!({
            "properties": {
                "value": {
                    "oneOf": [
                        {"type": "integer"},
                        {"type": "null"}
                    ]
                }
            }
        });

        clean_json_schema(&mut schema);

        assert!(schema["properties"]["value"].get("oneOf").is_none());
        assert_eq!(schema["properties"]["value"]["type"], "integer");
    }

    // [NEW TEST] 验证已有 type 不被覆盖
    #[test]
    fn test_existing_type_preserved() {
        let mut schema = json!({
            "properties": {
                "name": {
                    "type": "string",
                    "anyOf": [
                        {"type": "number"}
                    ]
                }
            }
        });

        clean_json_schema(&mut schema);

        // type 已存在，不应被 anyOf 中的类型覆盖
        assert_eq!(schema["properties"]["name"]["type"], "string");
        assert!(schema["properties"]["name"].get("anyOf").is_none());
    }

    // [NEW TEST] 验证 Issue #815: anyOf 内部属性不丢失
    #[test]
    fn test_issue_815_anyof_properties_preserved() {
        let mut schema = json!({
            "type": "object",
            "properties": {
                "config": {
                    "anyOf": [
                        {
                            "type": "object",
                            "properties": {
                                "path": { "type": "string" },
                                "recursive": { "type": "boolean" }
                            },
                            "required": ["path"]
                        },
                        { "type": "null" }
                    ]
                }
            }
        });

        clean_json_schema(&mut schema);

        let config = &schema["properties"]["config"];

        // 1. 验证类型被提取
        assert_eq!(config["type"], "object");

        // 2. 验证 anyOf 内部的 properties 被合并上来了
        assert!(config.get("properties").is_some());
        assert_eq!(config["properties"]["path"]["type"], "string");
        assert_eq!(config["properties"]["recursive"]["type"], "boolean");

        // 3. 验证 required 被合并上来了
        let req = config["required"].as_array().unwrap();
        assert!(req.iter().any(|v| v == "path"));

        // 4. 验证 anyOf 字段本身被移除
        assert!(config.get("anyOf").is_none());

        // 5. 验证没有因为“空”而注入 reason (因为我们保留了属性)
        assert!(config["properties"].get("reason").is_none());
    }

    // [NEW TEST] 验证安全检查：不应处理非 Schema 对象（保护工具调用）
    #[test]
    fn test_clean_json_schema_on_non_schema_object() {
        // 模拟 request.rs 中转换了一半的 functionCall 对象
        let mut tool_call = json!({
            "functionCall": {
                "name": "local_shell_call",
                "args": { "command": ["ls"] },
                "id": "call_123"
            }
        });

        // 调用清洗逻辑
        clean_json_schema(&mut tool_call);

        // 验证：这些非 Schema 字段不应被移除（因为不符合 looks_like_schema 判定）
        let fc = &tool_call["functionCall"];
        assert_eq!(fc["name"], "local_shell_call");
        assert_eq!(fc["args"]["command"][0], "ls");
        assert_eq!(fc["id"], "call_123");
    }

    // [NEW TEST] 验证 Nullable 处理
    #[test]
    fn test_nullable_handling_with_description() {
        let mut schema = json!({
            "type": ["string", "null"],
            "description": "User name"
        });

        clean_json_schema(&mut schema);

        // 验证 type 被降级，且描述被追加 (nullable)
        assert_eq!(schema["type"], "string");
        assert!(schema["description"]
            .as_str()
            .unwrap()
            .contains("User name"));
        assert!(schema["description"]
            .as_str()
            .unwrap()
            .contains("(nullable)"));
    }

    // [NEW TEST] 验证 anyOf 内部的 propertyNames 被移除
    #[test]
    fn test_clean_anyof_with_propertynames() {
        let mut schema = json!({
            "properties": {
                "config": {
                    "anyOf": [
                        {
                            "type": "object",
                            "propertyNames": {"pattern": "^[a-z]+$"},
                            "properties": {
                                "key": {"type": "string"}
                            }
                        },
                        {"type": "null"}
                    ]
                }
            }
        });

        clean_json_schema(&mut schema);

        // 验证 anyOf 被移除（已被合并）
        let config = &schema["properties"]["config"];
        assert!(config.get("anyOf").is_none());

        // 验证 propertyNames 被移除
        assert!(config.get("propertyNames").is_none());

        // 验证合并后的 properties 存在且没有 propertyNames
        assert!(config.get("properties").is_some());
        assert_eq!(config["properties"]["key"]["type"], "string");
    }

    // [NEW TEST] 验证 items 数组中的 const 被移除
    #[test]
    fn test_clean_items_array_with_const() {
        let mut schema = json!({
            "type": "array",
            "items": {
                "type": "object",
                "properties": {
                    "status": {
                        "const": "active",
                        "type": "string"
                    }
                }
            }
        });

        clean_json_schema(&mut schema);

        // 验证 const 被移除
        let status = &schema["items"]["properties"]["status"];
        assert!(status.get("const").is_none());

        // 验证 type 仍然存在
        assert_eq!(status["type"], "string");
    }

    // [NEW TEST] 验证多层嵌套数组的清理
    #[test]
    fn test_deep_nested_array_cleaning() {
        let mut schema = json!({
            "properties": {
                "data": {
                    "anyOf": [
                        {
                            "type": "array",
                            "items": {
                                "anyOf": [
                                    {
                                        "type": "object",
                                        "propertyNames": {"maxLength": 10},
                                        "const": "test",
                                        "properties": {
                                            "name": {"type": "string"}
                                        }
                                    },
                                    {"type": "null"}
                                ]
                            }
                        }
                    ]
                }
            }
        });

        clean_json_schema(&mut schema);

        // 验证深层嵌套的非法字段都被移除
        let data = &schema["properties"]["data"];

        // anyOf 应该被合并移除
        assert!(data.get("anyOf").is_none());

        // 验证没有 propertyNames 和 const 逃逸到顶层
        assert!(data.get("propertyNames").is_none());
        assert!(data.get("const").is_none());

        // 验证结构被正确保留
        assert_eq!(data["type"], "array");
        if let Some(items) = data.get("items") {
            // items 内部的 anyOf 也应该被合并
            assert!(items.get("anyOf").is_none());
            assert!(items.get("propertyNames").is_none());
            assert!(items.get("const").is_none());
        }
    }

    #[test]
    fn test_fix_tool_call_args() {
        let mut args = serde_json::json!({
            "port": "8080",
            "enabled": "true",
            "timeout": "5.5",
            "metadata": {
                "retry": "3"
            },
            "tags": ["1", "2"]
        });

        let schema = serde_json::json!({
            "properties": {
                "port": { "type": "integer" },
                "enabled": { "type": "boolean" },
                "timeout": { "type": "number" },
                "metadata": {
                    "type": "object",
                    "properties": {
                        "retry": { "type": "integer" }
                    }
                },
                "tags": {
                    "type": "array",
                    "items": { "type": "integer" }
                }
            }
        });

        fix_tool_call_args(&mut args, &schema);

        assert_eq!(args["port"], 8080);
        assert_eq!(args["enabled"], true);
        assert_eq!(args["timeout"], 5.5);
        assert_eq!(args["metadata"]["retry"], 3);
        assert_eq!(args["tags"], serde_json::json!([1, 2]));
    }

    #[test]
    fn test_fix_tool_call_args_protection() {
        let mut args = serde_json::json!({
            "version": "01.0",
            "code": "007"
        });

        let schema = serde_json::json!({
            "properties": {
                "version": { "type": "number" },
                "code": { "type": "integer" }
            }
        });

        fix_tool_call_args(&mut args, &schema);

        // 应保留字符串以防破坏语义
        assert_eq!(args["version"], "01.0");
        assert_eq!(args["code"], "007");
    }

    // [NEW TEST #952] 验证嵌套层级的 $defs 能被正确收集和展开
    #[test]
    fn test_nested_defs_flattening() {
        // MCP 工具常常将 $defs 嵌套在 properties 内部，而非根层级
        let mut schema = json!({
            "type": "object",
            "properties": {
                "config": {
                    "$defs": {
                        "Address": {
                            "type": "object",
                            "properties": {
                                "city": { "type": "string" },
                                "zip": { "type": "string" }
                            }
                        }
                    },
                    "type": "object",
                    "properties": {
                        "home": { "$ref": "#/$defs/Address" },
                        "work": { "$ref": "#/$defs/Address" }
                    }
                }
            }
        });

        clean_json_schema(&mut schema);

        // 验证嵌套的 $ref 被正确解析
        let home = &schema["properties"]["config"]["properties"]["home"];
        assert_eq!(
            home["type"], "object",
            "home should have type 'object' from resolved $ref"
        );
        assert_eq!(
            home["properties"]["city"]["type"], "string",
            "home.properties.city should exist from resolved Address"
        );

        // 验证没有残留的 $ref
        assert!(
            home.get("$ref").is_none(),
            "home should not have orphan $ref"
        );

        // 验证 work 也被正确解析
        let work = &schema["properties"]["config"]["properties"]["work"];
        assert_eq!(work["type"], "object");
        assert!(work.get("$ref").is_none());
    }

    // [NEW TEST #952] 验证无法解析的 $ref 被优雅降级
    #[test]
    fn test_unresolved_ref_fallback() {
        let mut schema = json!({
            "type": "object",
            "properties": {
                "external": { "$ref": "https://example.com/schemas/External.json" },
                "missing": { "$ref": "#/$defs/NonExistent" }
            }
        });

        clean_json_schema(&mut schema);

        // 验证外部引用被降级为 string 类型
        let external = &schema["properties"]["external"];
        assert_eq!(
            external["type"], "string",
            "unresolved external $ref should fallback to string"
        );
        assert!(
            external["description"]
                .as_str()
                .unwrap()
                .contains("Unresolved $ref"),
            "description should contain unresolved $ref hint"
        );

        // 验证内部缺失引用也被降级
        let missing = &schema["properties"]["missing"];
        assert_eq!(missing["type"], "string");
        assert!(missing["description"]
            .as_str()
            .unwrap()
            .contains("NonExistent"));
    }

    // [NEW TEST #952] 验证深层嵌套的多级 $defs 都能被收集
    #[test]
    fn test_deeply_nested_multi_level_defs() {
        let mut schema = json!({
            "type": "object",
            "$defs": {
                "RootDef": { "type": "integer" }
            },
            "properties": {
                "level1": {
                    "type": "object",
                    "$defs": {
                        "Level1Def": { "type": "boolean" }
                    },
                    "properties": {
                        "level2": {
                            "type": "object",
                            "$defs": {
                                "Level2Def": { "type": "number" }
                            },
                            "properties": {
                                "useRoot": { "$ref": "#/$defs/RootDef" },
                                "useLevel1": { "$ref": "#/$defs/Level1Def" },
                                "useLevel2": { "$ref": "#/$defs/Level2Def" }
                            }
                        }
                    }
                }
            }
        });

        clean_json_schema(&mut schema);

        let level2_props = &schema["properties"]["level1"]["properties"]["level2"]["properties"];

        // 验证所有层级的 $defs 都被正确解析
        assert_eq!(
            level2_props["useRoot"]["type"], "integer",
            "RootDef should resolve"
        );
        assert_eq!(
            level2_props["useLevel1"]["type"], "boolean",
            "Level1Def should resolve"
        );
        assert_eq!(
            level2_props["useLevel2"]["type"], "number",
            "Level2Def should resolve"
        );

        // 验证没有残留 $ref
        assert!(level2_props["useRoot"].get("$ref").is_none());
        assert!(level2_props["useLevel1"].get("$ref").is_none());
        assert!(level2_props["useLevel2"].get("$ref").is_none());
    }

    // [NEW TEST] 验证对非标准字段（如 cornerRadius）的清洗和启发式修复
    #[test]
    fn test_non_standard_field_cleaning_and_healing() {
        let mut schema = json!({
            "type": "array",
            "items": {
                "cornerRadius": { "type": "number" },
                "fillColor": { "type": "string" }
            }
        });

        clean_json_schema(&mut schema);

        // 验证 items 中的非标准字段被移动到了 properties 内部，并增加了 type: object
        let items = &schema["items"];
        assert_eq!(items["type"], "object", "Malformed items should be healed to type object");
        assert!(items.get("properties").is_some(), "Malformed items should have properties object");
        assert_eq!(items["properties"]["cornerRadius"]["type"], "number");
        assert_eq!(items["properties"]["fillColor"]["type"], "string");
        
        // 验证原始字段已从 items 顶层移除（白名单过滤）
        assert!(items.get("cornerRadius").is_none());
        assert!(items.get("fillColor").is_none());
    }

    // [NEW TEST] 验证隐式 Array (只有 items) 和隐式 Object (只有 properties) 的处理
    #[test]
    fn test_implicit_type_injection() {
        let mut schema = json!({
            "properties": {
                "values": {
                    "items": {
                        "cornerRadius": { "type": "number" }
                    }
                }
            }
        });

        clean_json_schema(&mut schema);

        // 验证 values 被注入了 type: array
        assert_eq!(schema["properties"]["values"]["type"], "array");
        
        // 验证 items 被启发式修复为 type: object 并包含 properties
        let items = &schema["properties"]["values"]["items"];
        assert_eq!(items["type"], "object");
        assert!(items["properties"].get("cornerRadius").is_some());
    }

    #[test]
    fn test_gemini_strict_validation_injection() {
        let mut schema = json!({
            "type": "object",
            "properties": {
                "patterns": {
                    "items": {
                        "properties": {
                            "type": {
                                "enum": ["A", "B"]
                            }
                        }
                    }
                },
                "nested_props": {
                    "properties": {
                        "foo": { "type": "string" }
                    }
                }
            }
        });

        clean_json_schema(&mut schema);

        // 验证 enum 自动补全了 type: string
        let type_node = &schema["properties"]["patterns"]["items"]["properties"]["type"];
        assert_eq!(type_node["type"], "string");
        assert!(type_node.get("enum").is_some());

        // 验证 嵌套 properties 自动补全了 type: object
        assert_eq!(schema["properties"]["nested_props"]["type"], "object");

        // 验证 patterns 自动补全了 type: array
        assert_eq!(schema["properties"]["patterns"]["type"], "array");
    }
    #[test]
    fn test_malformed_items_as_properties() {
        let mut schema = json!({
            "type": "object",
            "properties": {
                "config": {
                    "type": "object",
                    "items": {
                        "color": { "type": "string" },
                        "size": { "type": "number" }
                    }
                }
            }
        });

        clean_json_schema(&mut schema);

        // 验证 items 被移除并转换为 properties
        let config = &schema["properties"]["config"];
        assert!(config.get("items").is_none());
        assert_eq!(config["properties"]["color"]["type"], "string");
        assert_eq!(config["properties"]["size"]["type"], "number");
        assert_eq!(config["type"], "object");
    }

    #[test]
    fn test_circular_ref_flattening() {
        // 模拟循环引用：A -> B, B -> A
        let mut schema = json!({
            "$defs": {
                "A": {
                    "type": "object",
                    "properties": {
                        "toB": { "$ref": "#/$defs/B" }
                    }
                },
                "B": {
                    "type": "object",
                    "properties": {
                        "toA": { "$ref": "#/$defs/A" }
                    }
                }
            },
            "properties": {
                "start": { "$ref": "#/$defs/A" }
            }
        });

        // 如果没有深度限制，这里会发生栈溢出
        // 有了深度限制，它应该能正常返回（尽管展开是不完整的）
        clean_json_schema(&mut schema);

        // 验证基本结构保留，没有崩溃
        assert_eq!(schema["properties"]["start"]["type"], "object");
        assert!(schema["properties"]["start"]["properties"].get("toB").is_some());
    }

    #[test]
    fn test_any_of_best_branch_selection() {
        let mut schema = json!({
            "anyOf": [
                { "type": "string" },
                { "type": "object", "properties": { "foo": { "type": "string" } } },
                { "type": "null" }
            ]
        });

        clean_json_schema(&mut schema);

        // 验证选择了分数最高的 Object 分支
        assert_eq!(schema["type"], "object");
        assert!(schema.get("properties").is_some());
        assert_eq!(schema["properties"]["foo"]["type"], "string");
        
        // 验证描述中增加了类型提示 (注意: null 分支在清洗后变为了带 (nullable) 标记的 string，因此去重后为 string | object)
        assert!(schema["description"].as_str().unwrap().contains("Accepts: string | object"));
    }
}