import sqlite3
import json
from contextlib import contextmanager
from typing import List, Dict, Any, Tuple
from config import DB_PATH

@contextmanager
def get_db_connection():
    """Context manager for database connections."""
    conn = sqlite3.connect(DB_PATH)
    conn.row_factory = sqlite3.Row
    try:
        yield conn
    finally:
        conn.close()

def fetch_all_embeddings(table: str) -> List[Tuple[int, str, List[float]]]:
    """Fetch all embeddings from a table."""
    with get_db_connection() as conn:
        cur = conn.cursor()
        cur.execute(f"SELECT id, full_text, embedding FROM {table}")
        rows = cur.fetchall()
        
    parsed = []
    for row in rows:
        try:
            parsed.append((row['id'], row['full_text'], json.loads(row['embedding'])))
        except (json.JSONDecodeError, TypeError):
            continue
    return parsed

def fetch_row_by_id(table: str, row_id: int) -> Dict[str, Any]:
    """Fetch a single row by ID."""
    with get_db_connection() as conn:
        cur = conn.cursor()
        cur.execute(f"SELECT * FROM {table} WHERE id = ?", (row_id,))
        row = cur.fetchone()
        return dict(row) if row else {}

def fetch_all_faq_embeddings() -> List[Tuple[int, str, str, List[float]]]:
    """Fetch all FAQ embeddings."""
    with get_db_connection() as conn:
        cur = conn.cursor()
        cur.execute("SELECT id, question, answer, embedding FROM faq_entries")
        rows = cur.fetchall()
        
    parsed = []
    for row in rows:
        try:
            parsed.append((row['id'], row['question'], row['answer'], json.loads(row['embedding'])))
        except (json.JSONDecodeError, TypeError):
            continue
    return parsed

def log_question(
    question: str, 
    session_id: str = None, 
    category: str = None, 
    answer: str = None,
    detected_mode: str = None,
    routing_question: str = None,
    rule_triggered: str = None,
    link_provided: bool = False
):
    """Log a user question to the database with comprehensive observability metadata.
    
    Args:
        question: The user's question
        session_id: Session identifier
        category: Question category (e.g., 'faq_match', 'llm_generated', 'policy_violation')
        answer: The bot's response
        detected_mode: Operating mode ('Mode A' or 'Mode B')
        routing_question: The routing question asked (if any)
        rule_triggered: Business rule that was triggered (e.g., 'audit_rule', 'free_class_first')
        link_provided: Whether a direct link was included in the response
    """
    with get_db_connection() as conn:
        cur = conn.cursor()
        
        try:
            cur.execute("""
                INSERT INTO question_logs (
                    session_id, question, category, answer, 
                    detected_mode, routing_question, rule_triggered, link_provided
                ) 
                VALUES (?, ?, ?, ?, ?, ?, ?, ?)
            """, (
                session_id, question, category, answer,
                detected_mode, routing_question, rule_triggered, 
                1 if link_provided else 0
            ))
        except sqlite3.OperationalError as e:
            # Fallback for older schema versions (shouldn't happen after migration)
            print(f"⚠️  Logging error: {e}. Falling back to basic logging.")
        conn.commit()

def get_recent_history(session_id: str, limit: int = 5) -> List[Dict[str, str]]:
    """Retrieve recent conversation history for a session from the logs."""
    if not session_id:
        return []
        
    with get_db_connection() as conn:
        cur = conn.cursor()
        cur.execute("""
            SELECT question, answer 
            FROM question_logs 
            WHERE session_id = ? 
            AND answer IS NOT NULL
            ORDER BY timestamp DESC 
            LIMIT ?
        """, (session_id, limit))
        rows = cur.fetchall()
        
    # Reverse to get chronological order
    history = []
    for row in reversed(rows):
        history.append({"role": "user", "content": row['question']})
        history.append({"role": "assistant", "content": row['answer']})
    return history

def get_session_state(session_id: str) -> Dict[str, Any]:
    """Get session state from DB"""
    with get_db_connection() as conn:
        cur = conn.cursor()
        cur.execute("SELECT * FROM user_sessions WHERE session_id = ?", (session_id,))
        row = cur.fetchone()
        if row:
            return dict(row)
    return {"preference": None, "msg_count": 0, "clarification_count": 0, "knowledge_context": "{}"}

def update_session_state(session_id: str, preference: str = None, increment_count: bool = True, increment_clarification: bool = False, reset_clarification: bool = False, knowledge_update: Dict = None):
    """Update session state with Knowledge Dictionary support"""
    with get_db_connection() as conn:
        cur = conn.cursor()
        
        # Check if exists
        cur.execute("SELECT preference, msg_count, clarification_count, knowledge_context FROM user_sessions WHERE session_id = ?", (session_id,))
        row = cur.fetchone()
        
        current_knowledge = {}
        if row:
            curr_pref, curr_count, curr_clarification, curr_knowledge_json = row
            try:
                current_knowledge = json.loads(curr_knowledge_json)
            except:
                current_knowledge = {}

            new_pref = preference if preference else curr_pref
            new_count = curr_count + 1 if increment_count else curr_count
            
            # 10-Message Memory Rule: Reset if we hit the limit
            if new_count > 10:
                print(f"🔄 Session {session_id} reached 10 messages. Resetting memory context.")
                new_count = 1
                new_pref = None
                current_knowledge = {}
                new_clarification = 0
            else:
                new_clarification = curr_clarification
                if reset_clarification:
                    new_clarification = 0
                elif increment_clarification:
                    new_clarification = curr_clarification + 1
            
            # Merge knowledge updates
            if knowledge_update:
                current_knowledge.update(knowledge_update)
                
            new_knowledge_json = json.dumps(current_knowledge)

            cur.execute("""
                UPDATE user_sessions 
                SET preference = ?, msg_count = ?, clarification_count = ?, knowledge_context = ?, last_updated = CURRENT_TIMESTAMP 
                WHERE session_id = ?
            """, (new_pref, new_count, new_clarification, new_knowledge_json, session_id))
        else:
            new_pref = preference
            new_count = 1 if increment_count else 0
            new_clarification = 1 if increment_clarification else 0
            
            if knowledge_update:
                current_knowledge.update(knowledge_update)
            new_knowledge_json = json.dumps(current_knowledge)
            
            cur.execute("""
                INSERT INTO user_sessions (session_id, preference, msg_count, clarification_count, knowledge_context)
                VALUES (?, ?, ?, ?, ?)
            """, (session_id, new_pref, new_count, new_clarification, new_knowledge_json))
            
        conn.commit()

def update_faq_entry(faq_id: int, question: str, answer: str):
    """Update an existing FAQ entry."""
    with get_db_connection() as conn:
        cur = conn.cursor()
        cur.execute(
            "UPDATE faq_entries SET question = ?, answer = ?, embedding = NULL WHERE id = ?",
            (question, answer, faq_id)
        )
        conn.commit()

def delete_faq_entry(faq_id: int):
    """Delete an FAQ entry."""
    with get_db_connection() as conn:
        cur = conn.cursor()
        cur.execute("DELETE FROM faq_entries WHERE id = ?", (faq_id,))
        conn.commit()

def add_faq_entry(question: str, answer: str):
    """Add a new FAQ entry."""
    with get_db_connection() as conn:
        cur = conn.cursor()
        cur.execute(
            "INSERT INTO faq_entries (question, answer) VALUES (?, ?)",
            (question, answer)
        )
        conn.commit()

def bulk_update_faqs(entries: List[Dict[str, str]]):
    """Bulk update FAQs from a list of dictionaries."""
    with get_db_connection() as conn:
        cur = conn.cursor()
        for entry in entries:
            question = entry.get('Question') or entry.get('question')
            answer = entry.get('Answer') or entry.get('answer')
            if question and answer:
                cur.execute(
                    "INSERT INTO faq_entries (question, answer) VALUES (?, ?)",
                    (question, answer)
                )
        conn.commit()

def bulk_update_podcasts(entries: List[Dict[str, str]]):
    """Bulk update Podcasts from a list of dictionaries."""
    with get_db_connection() as conn:
        cur = conn.cursor()
        for entry in entries:
            guest = entry.get('Guest Name') or entry.get('guest_name')
            url = entry.get('YouTube URL') or entry.get('youtube_url')
            summary = entry.get('Summary') or entry.get('summary')
            if guest and url and summary:
                # Format full_text as required by the existing logic
                full_text = f"Guest: {guest}. Summary: {summary}"
                # Store summary in highlight_json as a simple list for compatibility
                h_json = json.dumps([{"summary": summary}])
                cur.execute(
                    "INSERT INTO podcast_episodes (guest_name, youtube_url, highlight_json, full_text) VALUES (?, ?, ?, ?)",
                    (guest, url, h_json, full_text)
                )
        conn.commit()

def fetch_all_podcast_metadata() -> List[Dict[str, Any]]:
    """Fetch all podcast metadata for the admin table."""
    with get_db_connection() as conn:
        cur = conn.cursor()
        cur.execute("SELECT id, guest_name, youtube_url, highlight_json FROM podcast_episodes")
        rows = cur.fetchall()
        results = []
        for row in rows:
            d = dict(row)
            # Try to extract plain summary from JSON for the table
            try:
                h = json.loads(d['highlight_json'])
                d['summary'] = h[0]['summary'] if h and isinstance(h, list) else d['highlight_json']
            except:
                d['summary'] = d['highlight_json']
            results.append(d)
        return results

def fetch_all_faq_metadata() -> List[Dict[str, Any]]:
    """Fetch all FAQ metadata for the admin table."""
    with get_db_connection() as conn:
        cur = conn.cursor()
        cur.execute("SELECT id, question, answer FROM faq_entries")
        return [dict(row) for row in cur.fetchall()]