// Package testutil 提供测试工具和辅助函数
package testutil

import (
	"crypto/rand"
	"encoding/hex"
	"fmt"
	"net/http"
	"strings"

	"ccLoad/internal/model"
	"ccLoad/internal/util"
	"ccLoad/internal/version"

	"github.com/bytedance/sonic"
)

// ChannelTester 定义不同渠道类型的测试协议（OCP：新增类型无需修改调用方）
type ChannelTester interface {
	// Build 构造完整请求：URL、基础请求头、请求体
	// apiKey: 实际使用的API Key字符串（由调用方从数据库查询）
	Build(cfg *model.Config, apiKey string, req *TestChannelRequest) (fullURL string, headers http.Header, body []byte, err error)
	// Parse 解析响应体，返回通用结果字段（如 response_text、usage、api_response/api_error/raw_response）
	Parse(statusCode int, respBody []byte) map[string]any
}

// === 泛型类型安全工具函数 ===

// getTypedValue 从map中安全获取指定类型的值（消除类型断言嵌套）
func getTypedValue[T any](m map[string]any, key string) (T, bool) {
	var zero T
	v, ok := m[key]
	if !ok {
		return zero, false
	}
	typed, ok := v.(T)
	return typed, ok
}

// getSliceItem 从切片中安全获取指定索引的指定类型元素
func getSliceItem[T any](slice []any, index int) (T, bool) {
	var zero T
	if index < 0 || index >= len(slice) {
		return zero, false
	}
	typed, ok := slice[index].(T)
	return typed, ok
}

func extractStructuredAPIError(apiResp map[string]any) (string, bool) {
	if errInfo, ok := getTypedValue[map[string]any](apiResp, "error"); ok {
		if msg, ok := getTypedValue[string](errInfo, "message"); ok && strings.TrimSpace(msg) != "" {
			return msg, true
		}
		if typeStr, ok := getTypedValue[string](errInfo, "type"); ok && strings.TrimSpace(typeStr) != "" {
			return typeStr, true
		}
		if code, ok := getTypedValue[string](errInfo, "code"); ok && strings.TrimSpace(code) != "" {
			return code, true
		}
		return "上游返回结构化错误", true
	}

	objectType, hasObjectType := getTypedValue[string](apiResp, "object")
	status, hasStatus := getTypedValue[string](apiResp, "status")
	if hasObjectType && objectType == "response" && hasStatus {
		normalizedStatus := strings.ToLower(strings.TrimSpace(status))
		if normalizedStatus != "" && normalizedStatus != "completed" {
			if details, ok := getTypedValue[map[string]any](apiResp, "incomplete_details"); ok {
				if reason, ok := getTypedValue[string](details, "reason"); ok && strings.TrimSpace(reason) != "" {
					return "响应未完成: " + reason, true
				}
			}
			return "响应状态为 " + status, true
		}
	}

	return "", false
}

func finalizeParsedAPIResponse(out map[string]any, apiResp map[string]any) map[string]any {
	out["api_response"] = apiResp
	if errorMsg, ok := extractStructuredAPIError(apiResp); ok {
		out["success"] = false
		out["error"] = errorMsg
		out["api_error"] = apiResp
	}
	return out
}

func parseAPIResponse(respBody []byte, extractText func(map[string]any) (string, bool), usageKey string) map[string]any {
	out := map[string]any{}
	var apiResp map[string]any
	if err := sonic.Unmarshal(respBody, &apiResp); err == nil {
		if extractText != nil {
			if text, ok := extractText(apiResp); ok {
				out["response_text"] = text
			}
		}
		if usageKey != "" {
			if usage, ok := getTypedValue[map[string]any](apiResp, usageKey); ok {
				out["usage"] = usage
			}
		}
		return finalizeParsedAPIResponse(out, apiResp)
	}
	out["raw_response"] = string(respBody)
	return out
}

func buildTesterURL(baseURL, endpointSuffix string) string {
	if model.HasExactUpstreamURLMarker(baseURL) {
		return model.StripExactUpstreamURLMarker(baseURL)
	}
	return strings.TrimRight(strings.TrimSpace(baseURL), "/") + endpointSuffix
}

// CodexTester 兼容 Codex 风格（渠道类型: codex）
type CodexTester struct{}

// Build 构建 Codex 格式的 API 请求
func (t *CodexTester) Build(cfg *model.Config, apiKey string, req *TestChannelRequest) (string, http.Header, []byte, error) {
	testContent := req.Content
	if strings.TrimSpace(testContent) == "" {
		testContent = "test"
	}

	body, err := buildRequestFromTemplate("codex", map[string]any{
		"MODEL":   req.Model,
		"STREAM":  req.Stream,
		"CONTENT": testContent,
	})
	if err != nil {
		return "", nil, nil, err
	}

	fullURL := buildTesterURL(cfg.GetURLs()[0], "/v1/responses")

	h := make(http.Header)
	h.Set("Content-Type", "application/json")
	h.Set("Authorization", "Bearer "+apiKey)
	h.Set("User-Agent", "codex_cli_rs/0.41.0 (Mac OS 26.0.0; arm64) iTerm.app/3.6.1")
	h.Set("Openai-Beta", "responses=experimental")
	h.Set("Originator", "codex_cli_rs")
	if req.Stream {
		h.Set("Accept", "text/event-stream")
	}

	return fullURL, h, body, nil
}

// extractCodexResponseText 从Codex响应中提取文本（消除6层嵌套）
func extractCodexResponseText(apiResp map[string]any) (string, bool) {
	output, ok := getTypedValue[[]any](apiResp, "output")
	if !ok {
		return "", false
	}

	for _, item := range output {
		outputItem, ok := item.(map[string]any)
		if !ok {
			continue
		}

		outputType, ok := getTypedValue[string](outputItem, "type")
		if !ok || outputType != "message" {
			continue
		}

		content, ok := getTypedValue[[]any](outputItem, "content")
		if !ok || len(content) == 0 {
			continue
		}

		textBlock, ok := getSliceItem[map[string]any](content, 0)
		if !ok {
			continue
		}

		text, ok := getTypedValue[string](textBlock, "text")
		if ok {
			return text, true
		}
	}
	return "", false
}

// Parse 解析 Codex 格式的 API 响应
func (t *CodexTester) Parse(_ int, respBody []byte) map[string]any {
	return parseAPIResponse(respBody, extractCodexResponseText, "usage")
}

// OpenAITester 标准OpenAI API格式（渠道类型: openai）
type OpenAITester struct{}

// Build 构建 OpenAI 格式的 API 请求
func (t *OpenAITester) Build(cfg *model.Config, apiKey string, req *TestChannelRequest) (string, http.Header, []byte, error) {
	testContent := req.Content
	if strings.TrimSpace(testContent) == "" {
		testContent = "test"
	}
	sessionID := newTestSessionID()

	body, err := buildRequestFromTemplate("openai", map[string]any{
		"MODEL":      req.Model,
		"STREAM":     req.Stream,
		"CONTENT":    testContent,
		"SESSION_ID": sessionID,
	})
	if err != nil {
		return "", nil, nil, err
	}

	fullURL := buildTesterURL(cfg.GetURLs()[0], "/v1/chat/completions")

	h := make(http.Header)
	h.Set("Content-Type", "application/json")
	h.Set("Authorization", "Bearer "+apiKey)
	h.Set("Session_id", sessionID)
	h.Set("User-Agent", version.OutboundUserAgent())
	if req.Stream {
		h.Set("Accept", "text/event-stream")
	}

	return fullURL, h, body, nil
}

// Parse 解析 OpenAI 格式的 API 响应
func (t *OpenAITester) Parse(_ int, respBody []byte) map[string]any {
	out := map[string]any{}
	var apiResp map[string]any
	if err := sonic.Unmarshal(respBody, &apiResp); err == nil {
		// 提取choices[0].message.content
		if choices, ok := getTypedValue[[]any](apiResp, "choices"); ok && len(choices) > 0 {
			if choice, ok := getSliceItem[map[string]any](choices, 0); ok {
				if message, ok := getTypedValue[map[string]any](choice, "message"); ok {
					if content, ok := getTypedValue[string](message, "content"); ok {
						out["response_text"] = content
					}
				}
			}
		}

		// 提取usage
		if usage, ok := getTypedValue[map[string]any](apiResp, "usage"); ok {
			out["usage"] = usage
		}

		return finalizeParsedAPIResponse(out, apiResp)
	}
	out["raw_response"] = string(respBody)
	return out
}

// GeminiTester 实现 Google Gemini 测试协议
type GeminiTester struct{}

// Build 构建 Gemini 格式的 API 请求
func (t *GeminiTester) Build(cfg *model.Config, apiKey string, req *TestChannelRequest) (string, http.Header, []byte, error) {
	testContent := req.Content
	if strings.TrimSpace(testContent) == "" {
		testContent = "test"
	}

	body, err := buildRequestFromTemplate("gemini", map[string]any{
		"CONTENT": testContent,
	})
	if err != nil {
		return "", nil, nil, err
	}

	// Gemini API: 流式用 :streamGenerateContent?alt=sse，非流式用 :generateContent
	action := ":generateContent"
	if req.Stream {
		action = ":streamGenerateContent?alt=sse"
	}
	fullURL := buildTesterURL(cfg.GetURLs()[0], "/v1beta/models/"+req.Model+action)

	h := make(http.Header)
	h.Set("Content-Type", "application/json")
	h.Set("x-goog-api-key", apiKey)
	h.Set("User-Agent", version.OutboundUserAgent())

	return fullURL, h, body, nil
}

// extractGeminiResponseText 从Gemini响应中提取文本（消除5层嵌套）
func extractGeminiResponseText(apiResp map[string]any) (string, bool) {
	candidates, ok := getTypedValue[[]any](apiResp, "candidates")
	if !ok || len(candidates) == 0 {
		return "", false
	}

	candidate, ok := getSliceItem[map[string]any](candidates, 0)
	if !ok {
		return "", false
	}

	content, ok := getTypedValue[map[string]any](candidate, "content")
	if !ok {
		return "", false
	}

	parts, ok := getTypedValue[[]any](content, "parts")
	if !ok || len(parts) == 0 {
		return "", false
	}

	part, ok := getSliceItem[map[string]any](parts, 0)
	if !ok {
		return "", false
	}

	text, ok := getTypedValue[string](part, "text")
	return text, ok
}

// Parse 解析 Gemini 格式的 API 响应
func (t *GeminiTester) Parse(_ int, respBody []byte) map[string]any {
	return parseAPIResponse(respBody, extractGeminiResponseText, "usageMetadata")
}

func newTestSessionID() string {
	return util.NewUUIDv4()
}

// AnthropicTester 实现 Anthropic 测试协议
type AnthropicTester struct{}

// newClaudeCLIUserID 生成 Claude CLI 用户ID
func newClaudeCLIUserID() string {
	// Claude Code 真实格式：metadata.user_id 是一个 JSON 字符串
	// 例如：{"device_id":"76efe6...","account_uuid":"","session_id":"ce6c5d34-..."}
	deviceID := make([]byte, 32)
	if _, err := rand.Read(deviceID); err != nil {
		return `{"device_id":"0000000000000000000000000000000000000000000000000000000000000000","account_uuid":"","session_id":"00000000-0000-0000-0000-000000000000"}`
	}

	return fmt.Sprintf(`{"device_id":"%s","account_uuid":"","session_id":"%s"}`, hex.EncodeToString(deviceID), newTestSessionID())
}

// Build 构建 Anthropic 格式的 API 请求
func (t *AnthropicTester) Build(cfg *model.Config, apiKey string, req *TestChannelRequest) (string, http.Header, []byte, error) {
	maxTokens := req.MaxTokens
	if maxTokens == 0 {
		maxTokens = 32000
	}
	testContent := req.Content

	body, err := buildRequestFromTemplate("anthropic", map[string]any{
		"MODEL":      req.Model,
		"STREAM":     req.Stream,
		"CONTENT":    testContent,
		"MAX_TOKENS": maxTokens,
		"USER_ID":    newClaudeCLIUserID(),
	})
	if err != nil {
		return "", nil, nil, err
	}

	fullURL := buildTesterURL(cfg.GetURLs()[0], "/v1/messages?beta=true")

	h := make(http.Header)
	h.Set("Accept", "application/json")
	h.Set("Content-Type", "application/json")
	h.Set("Authorization", "Bearer "+apiKey)
	// Claude Code CLI headers
	h.Set("User-Agent", "claude-cli/2.1.97 (external, cli)")
	h.Set("x-app", "cli")
	h.Set("anthropic-version", "2023-06-01")
	h.Set("anthropic-beta", "claude-code-20250219,context-1m-2025-08-07,interleaved-thinking-2025-05-14,context-management-2025-06-27,prompt-caching-scope-2026-01-05,advanced-tool-use-2025-11-20,effort-2025-11-24")
	h.Set("anthropic-dangerous-direct-browser-access", "true")
	// x-stainless-* headers
	h.Set("x-stainless-arch", "arm64")
	h.Set("x-stainless-lang", "js")
	h.Set("x-stainless-os", "MacOS")
	h.Set("x-stainless-package-version", "0.81.0")
	h.Set("x-stainless-retry-count", "0")
	h.Set("x-stainless-runtime", "node")
	h.Set("x-stainless-runtime-version", "v24.3.0")
	h.Set("x-stainless-timeout", "300")
	h.Set("X-Claude-Code-Session-Id", newTestSessionID())
	if req.Stream {
		h.Set("x-stainless-helper-method", "stream")
	}

	return fullURL, h, body, nil
}

// extractAnthropicResponseText 从Anthropic响应中提取文本
// 遍历content数组，跳过thinking block，取第一个type=text的block
func extractAnthropicResponseText(apiResp map[string]any) (string, bool) {
	content, ok := getTypedValue[[]any](apiResp, "content")
	if !ok || len(content) == 0 {
		return "", false
	}

	for i := range content {
		block, ok := getSliceItem[map[string]any](content, i)
		if !ok {
			continue
		}
		// 优先匹配 type=text 的 block
		if blockType, ok := getTypedValue[string](block, "type"); ok && blockType != "text" {
			continue
		}
		if text, ok := getTypedValue[string](block, "text"); ok {
			return text, true
		}
	}
	return "", false
}

// Parse 解析 Anthropic 格式的 API 响应
func (t *AnthropicTester) Parse(_ int, respBody []byte) map[string]any {
	out := map[string]any{}
	var apiResp map[string]any
	if err := sonic.Unmarshal(respBody, &apiResp); err == nil {
		// 提取文本响应（使用辅助函数）
		if text, ok := extractAnthropicResponseText(apiResp); ok {
			out["response_text"] = text
		}

		// 提取usage（与其他Tester保持一致，便于上层统一处理）
		if usage, ok := getTypedValue[map[string]any](apiResp, "usage"); ok {
			out["usage"] = usage
		}

		return finalizeParsedAPIResponse(out, apiResp)
	}
	out["raw_response"] = string(respBody)
	return out
}