import os
import re
import json
import torch
from sentence_transformers import SentenceTransformer, util
from transformers import AutoTokenizer, AutoModelForSeq2SeqLM


# ==========================================
# STEP 1: Load Training Data Safely
# ==========================================
def load_training_data(data_folder):
    data = []
    missing_code = 0
    missing_query = 0

    for file in os.listdir(data_folder):
        if file.endswith(".json"):
            path = os.path.join(data_folder, file)
            with open(path, "r", encoding="utf-8") as f:
                try:
                    entries = json.load(f)
                    for e in entries:
                        if not e.get("pandas_code"):
                            missing_code += 1
                            continue
                        if not (e.get("english") or e.get("query")):
                            missing_query += 1
                            continue
                        data.append(e)
                except Exception as e:
                    print(f"⚠️ Skipped {file}: {e}")

    print(f"📚 Loaded {len(data)} valid query–code pairs from {data_folder}")
    print(f"⚠️ Skipped {missing_code} missing-code and {missing_query} missing-query entries.")
    return data


# ==========================================
# STEP 2: Enhanced Retriever
# ==========================================
class EnhancedRetriever:
    def __init__(self, data):
        self.model = SentenceTransformer("all-MiniLM-L6-v2")

        valid_data = [
            item for item in data
            if (item.get("pandas_code") and (item.get("english") or item.get("query")))
        ]

        if not valid_data:
            raise ValueError("No valid query–code pairs found in dataset!")

        self.queries = [
            item.get("english") or item.get("query")
            for item in valid_data
        ]
        self.codes = [item["pandas_code"] for item in valid_data]

        print(f"✅ Using {len(valid_data)} valid items for retrieval.")
        print("🧠 Encoding queries for retrieval...")
        self.query_embeddings = self.model.encode(self.queries, convert_to_tensor=True)

    def retrieve_best_match(self, user_query, top_k=3):
        user_emb = self.model.encode(user_query, convert_to_tensor=True)
        similarity = util.pytorch_cos_sim(user_emb, self.query_embeddings)[0]
        top_results = torch.topk(similarity, k=top_k)

        results = []
        for i in range(top_k):
            results.append({
                "query": self.queries[top_results.indices[i]],
                "pandas_code": self.codes[top_results.indices[i]],
                "similarity": float(top_results.values[i])
            })

        return results


# ==========================================
# STEP 3: Generator (CodeT5 / fine-tuned model)
# ==========================================
class Generator:
    def __init__(self, model_dir="./text2code_model"):
        if not os.path.exists(model_dir):
            print("⚙️ No fine-tuned model found — using base CodeT5.")
            model_dir = "Salesforce/codet5-small"

        self.tokenizer = AutoTokenizer.from_pretrained(model_dir)
        self.model = AutoModelForSeq2SeqLM.from_pretrained(model_dir)

    def generate(self, query):
        prompt = f"Generate Pandas code for: {query}"
        inputs = self.tokenizer(prompt, return_tensors="pt")
        outputs = self.model.generate(**inputs, max_length=128)
        return self.tokenizer.decode(outputs[0], skip_special_tokens=True)


# ==========================================
# STEP 4: Adaptation Utilities
# ==========================================
def extract_column_names(text):
    """Extract potential column names from text"""
    words = re.findall(r'\b[a-zA-Z_][a-zA-Z0-9_]*\b', text)
    stopwords = {
        'show', 'display', 'find', 'get', 'the', 'and', 'or', 'where',
        'what', 'how', 'many', 'much', 'list', 'give', 'me', 'all',
        'with', 'for', 'bottom', 'top', 'average', 'mean', 'sum',
        'median', 'count', 'minimum', 'maximum', 'highest', 'lowest'
    }
    cols =  [w for w in words if w.lower() not in stopwords and len(w) > 2]
    return [normalize_name(c) for c in cols]

def extract_values(text):
    """Extract quoted values and numbers from text"""
    quoted = re.findall(r"'([^']*)'", text)
    numbers = re.findall(r'\b\d+\b', text)
    return quoted + numbers

##commented for only the testing it is working but not only normalize
# def enhanced_adaptation(user_query, code, original_retrieved_query):
#     """More intelligent code adaptation"""
#     query_columns = extract_column_names(user_query)
#     original_columns = extract_column_names(original_retrieved_query)
#     query_values = extract_values(user_query)
#     original_values = extract_values(original_retrieved_query)

#     new_code = code

#     for orig_col, new_col in zip(original_columns, query_columns):
#         if orig_col and new_col and orig_col.lower() != new_col.lower():
#             for pattern in [rf"'{orig_col}'", rf'"{orig_col}"', rf"\b{orig_col}\b"]:
#                 new_code = re.sub(pattern, new_col, new_code, flags=re.IGNORECASE)

#     for orig_val, new_val in zip(original_values, query_values):
#         if orig_val and new_val and orig_val != new_val:
#             new_code = re.sub(rf"'{re.escape(orig_val)}'", f"'{new_val}'", new_code)
#             new_code = re.sub(rf'"{re.escape(orig_val)}"', f'"{new_val}"', new_code)
#             new_code = re.sub(rf"\b{re.escape(orig_val)}\b", new_val, new_code)

#     new_code = adapt_operations_based_on_query(user_query, new_code)
#     new_code = adapt_filters_based_on_query(user_query, new_code)

#     return new_code





def enhanced_adaptation(user_query, code, original_retrieved_query):
    """Smarter code adaptation with normalized column matching"""
    query_columns = extract_column_names(user_query)
    original_columns = extract_column_names(original_retrieved_query)
    query_values = extract_values(user_query)
    original_values = extract_values(original_retrieved_query)

    new_code = code

    # 🆕 Replace columns based on normalized mapping
    for orig_col, new_col in zip(original_columns, query_columns):
        if orig_col and new_col and normalize_name(orig_col) != normalize_name(new_col):
            for pattern in [rf"'{orig_col}'", rf'"{orig_col}"', rf"\b{orig_col}\b"]:
                new_code = re.sub(pattern, new_col, new_code, flags=re.IGNORECASE)

    # 🆕 Optional: map normalized query columns to known dataset columns
    if hasattr(bot, "col_map"):
        for norm_col in query_columns:
            if norm_col in bot.col_map:
                correct_name = bot.col_map[norm_col]
                new_code = re.sub(rf"\b{norm_col}\b", correct_name, new_code, flags=re.IGNORECASE)

    # Keep value and operation adaptation
    for orig_val, new_val in zip(original_values, query_values):
        if orig_val and new_val and orig_val != new_val:
            new_code = re.sub(rf"'{re.escape(orig_val)}'", f"'{new_val}'", new_code)
            new_code = re.sub(rf'"{re.escape(orig_val)}"', f'"{new_val}"', new_code)
            new_code = re.sub(rf"\b{re.escape(orig_val)}\b", new_val, new_code)

    new_code = adapt_operations_based_on_query(user_query, new_code)
    new_code = adapt_filters_based_on_query(user_query, new_code)

    return new_code

def adapt_operations_based_on_query(query, code):
    q = query.lower()
    c = code

    if any(word in q for word in ["average", "mean", "avg"]):
        c = re.sub(r"\.(sum|min|max|count)\(\)", ".mean()", c)
    elif any(word in q for word in ["total", "sum", "add", "together"]):
        c = re.sub(r"\.(mean|min|max|count)\(\)", ".sum()", c)
    elif any(word in q for word in ["minimum", "min", "lowest", "smallest"]):
        c = re.sub(r"\.(mean|sum|max|count)\(\)", ".min()", c)
    elif any(word in q for word in ["maximum", "max", "highest", "largest"]):
        c = re.sub(r"\.(mean|sum|min|count)\(\)", ".max()", c)
    elif any(word in q for word in ["count", "number", "how many"]):
        c = re.sub(r"\.(mean|sum|min|max)\(\)", ".count()", c)

    return c


def adapt_filters_based_on_query(query, code):
    q = query.lower()
    c = code

    if "status" in q and "rejected" in q:
        c = re.sub(r"df\[df\['\w+'\] == '[^']*'\]", "df[df['Status'] == 'rejected']", c)
    elif "status" in q and "approved" in q:
        c = re.sub(r"df\[df\['\w+'\] == '[^']*'\]", "df[df['Status'] == 'approved']", c)

    if "top" in q and "head" not in c:
        nums = re.findall(r'\d+', q)
        if nums:
            c = re.sub(r"\.tail\(\d+\)", f".head({nums[0]})", c)
            if "head" not in c and "sort_values" in c:
                c += f".head({nums[0]})"
    elif "bottom" in q and "tail" not in c:
        nums = re.findall(r'\d+', q)
        if nums:
            c = re.sub(r"\.head\(\d+\)", f".tail({nums[0]})", c)
            if "tail" not in c and "sort_values" in c:
                c += f".tail({nums[0]})"

    return c


# ==========================================
# STEP 5: Template Selection
# ==========================================
def select_best_template(retrieved_results, user_query):
    user_query_lower = user_query.lower()
    user_ops = []

    if any(op in user_query_lower for op in ['average', 'mean', 'avg']): user_ops.append('mean')
    if any(op in user_query_lower for op in ['sum', 'total']): user_ops.append('sum')
    if any(op in user_query_lower for op in ['median']): user_ops.append('median')
    if any(op in user_query_lower for op in ['count', 'number']): user_ops.append('count')
    if any(op in user_query_lower for op in ['minimum', 'min', 'lowest']): user_ops.append('min')
    if any(op in user_query_lower for op in ['maximum', 'max', 'highest']): user_ops.append('max')
    if any(op in user_query_lower for op in ['group', 'grouped']): user_ops.append('groupby')
    if any(op in user_query_lower for op in ['filter', 'where', 'condition']): user_ops.append('filter')

    best_score = -1
    best_result = retrieved_results[0]

    for result in retrieved_results:
        score = result["similarity"]
        code = result["pandas_code"].lower()

        for op in user_ops:
            if op in code:
                score += 0.1

        if 'groupby' in user_ops and 'groupby' in code:
            score += 0.15
        if 'filter' in user_ops and 'df[' in code and '==' in code:
            score += 0.15

        if score > best_score:
            best_score = score
            best_result = result

    return best_result


# ==========================================
# STEP 6: Validation & Post-Processing
# ==========================================
def validate_code_against_query(code, user_query):
    query_lower = user_query.lower()
    code_lower = code.lower()
    issues = []

    if any(w in query_lower for w in ['average', 'mean', 'avg']) and 'mean' not in code_lower:
        issues.append("Query asks for average but code doesn't use mean()")
    if any(w in query_lower for w in ['sum', 'total']) and 'sum' not in code_lower:
        issues.append("Query asks for sum but code doesn't use sum()")
    if 'median' in query_lower and 'median' not in code_lower:
        issues.append("Query asks for median but code doesn't use median()")
    if any(w in query_lower for w in ['group', 'grouped']) and 'groupby' not in code_lower:
        issues.append("Query asks for grouping but code doesn't use groupby()")
    if any(w in query_lower for w in ['filter', 'where']) and '==' not in code_lower:
        issues.append("Query asks for filtering but code doesn't have filter condition")

    return issues


def post_process_code(code, user_query):
    code = re.sub(r'\.groupby\(\)\.groupby\(\)', '.groupby()', code)
    if 'df[' not in code and "df." not in code and "groupby" in code:
        code = f"df.{code}" if "=" not in code else f"df[{code}]"
    code = re.sub(r'\.\.', '.', code)
    return code

def normalize_name(name):
    """Normalize column names for consistent comparison"""
    if not isinstance(name, str):
        return name
    # Lowercase, remove special chars and spaces
    return re.sub(r'[^a-z0-9]', '', name.lower())

# ==========================================
# STEP 7: Main Hybrid System
# ==========================================
class RobustHybridText2Code:
    def __init__(self, data_folder="data",
                 model_dir=r"D:\final_claimbotics\claimbotics_model\kaggle\working\codegen_model\final_model"):
        self.data = load_training_data(data_folder)
        self.retriever = EnhancedRetriever(self.data)
        self.generator = Generator(model_dir)
               
        all_cols = set()
        for item in self.data:
            code = item.get("pandas_code", "")
            # Extract column names from code strings
            cols = re.findall(r"df\[['\"]([^'\"]+)['\"]\]", code)
            all_cols.update(cols)
        self.col_map = {normalize_name(c): c for c in all_cols}

    def get_code(self, user_query):
        retrieved_results = self.retriever.retrieve_best_match(user_query, top_k=3)
        best = select_best_template(retrieved_results, user_query)

        print(f"🔍 [Best Match Similarity: {best['similarity']:.2f}]")
        print(f"📝 Original Query: {best['query']}")

        if best["similarity"] > 0.90:
            print("🎯 High similarity (≥ 0.90) — using code directly from data.")
            code = best["pandas_code"]
            
        elif best["similarity"] >= 0.75:
            print("🔄 Using retrieved code with enhanced adaptation...")
            code = enhanced_adaptation(user_query, best["pandas_code"], best["query"])
        else:
            print("🤖 Low similarity — generating new code...")
            code = self.generator.generate(user_query)

        code = post_process_code(code, user_query)
        issues = validate_code_against_query(code, user_query)
        if issues:
            print(f"⚠️ Validation issues: {issues}")

        return code


# ==========================================
# STEP 8: Run Interactive Chat
# ==========================================
if __name__ == "__main__":
    print("💬 Enhanced ClaimBotics Hybrid Text→Code System Ready!\n")
    print("=" * 60)

    bot = RobustHybridText2Code(
        data_folder="data",
        model_dir=r"D:\final_claimbotics\claimbotics_model\kaggle\working\codegen_model\final_model"
    )

    while True:
        user_input = input("\n🧑 You: ").strip()
        if user_input.lower() in ["exit", "quit", "bye"]:
            print("👋 Goodbye!")
            break
        if not user_input:
            continue

        try:
            code = bot.get_code(user_input)
            print(f"\n🤖 Suggested Pandas Code:\n{code}")
            print("=" * 60)
        except Exception as e:
            print(f"❌ Error: {e}")
            print("Please try again with a different query.")