import os
import sqlite3
from contextlib import contextmanager
from typing import Optional, Dict, Any, List, Tuple
from datetime import datetime

DEFAULT_DB_PATH = None  # set by set_db_path at runtime

def set_db_path(db_path: str):
    global DEFAULT_DB_PATH
    DEFAULT_DB_PATH = db_path
    os.makedirs(os.path.dirname(db_path), exist_ok=True)

def get_connection():
    if not DEFAULT_DB_PATH:
        raise ValueError("Database path not set. Call set_db_path(path) first.")
    return sqlite3.connect(DEFAULT_DB_PATH)
    
@contextmanager
def get_conn(db_path: Optional[str] = None):
    path = db_path or DEFAULT_DB_PATH
    conn = sqlite3.connect(path, check_same_thread=False)
    conn.row_factory = sqlite3.Row
    try:
        yield conn
        conn.commit()
    finally:
        conn.close()

def init_schema():
    with get_conn() as conn:
        c = conn.cursor()
        # (tus tablas existentes)
        c.execute("""
        CREATE TABLE IF NOT EXISTS users (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            username TEXT UNIQUE NOT NULL,
            password_hash TEXT,
            role TEXT NOT NULL,
            created_at TEXT NOT NULL
        );
        """)
        # Migraciones: asegurar columnas esperadas
        try:
            c.execute("PRAGMA table_info(users)")
            cols = {row[1] for row in c.fetchall()}  # set de nombres de columnas
            if "password_hash" not in cols:
                c.execute("ALTER TABLE users ADD COLUMN password_hash TEXT")
            if "role" not in cols:
                c.execute("ALTER TABLE users ADD COLUMN role TEXT NOT NULL DEFAULT 'verd'")
            if "created_at" not in cols:
                c.execute("ALTER TABLE users ADD COLUMN created_at TEXT NOT NULL DEFAULT ''")
        except sqlite3.OperationalError:
            pass
        # Intento de limpieza de columna antigua si existiera (SQLite no permite DROP COLUMN en versiones antiguas)
        try:
            c.execute("ALTER TABLE users DROP COLUMN pw_hash;")
        except sqlite3.OperationalError:
            pass
        # (opcional: tus otras tablas)

        # >>> NUEVA TABLA PARA FEEDBACK DE AD (no depende de videos)
        c.execute("""
        CREATE TABLE IF NOT EXISTS feedback_ad (
            id INTEGER PRIMARY KEY AUTOINCREMENT,
            video_name TEXT NOT NULL,          -- nombre de carpeta dentro de videos/completed
            user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
            transcripcio INTEGER NOT NULL,     -- 1..10
            identificacio INTEGER NOT NULL,    -- 1..10
            localitzacions INTEGER NOT NULL,   -- 1..10
            activitats INTEGER NOT NULL,       -- 1..10
            narracions INTEGER NOT NULL,       -- 1..10
            expressivitat INTEGER NOT NULL,    -- 1..10
            comments TEXT,
            created_at TEXT NOT NULL
        );
        """)
        # Add column if it doesn't exist, for backwards compatibility
        try:
            c.execute("ALTER TABLE feedback_ad ADD COLUMN expressivitat INTEGER NOT NULL DEFAULT 7;")
        except sqlite3.OperationalError:
            pass  # column already exists

def add_feedback_ad(video_name: str, user_id: int,
                    transcripcio: int, identificacio: int, localitzacions: int,
                    activitats: int, narracions: int, expressivitat: int, comments: str | None):
    with get_conn() as conn:
        conn.execute(
            """INSERT INTO feedback_ad
               (video_name, user_id, transcripcio, identificacio, localitzacions, activitats, narracions, expressivitat, comments, created_at)
               VALUES (?,?,?,?,?,?,?,?,?,?)""",
            (video_name, user_id, transcripcio, identificacio, localitzacions, activitats, narracions, expressivitat, comments, now_str())
        )

def get_feedback_ad_for_video(video_name: str):
    with get_conn() as conn:
        cur = conn.execute(
            """SELECT * FROM feedback_ad WHERE video_name=? ORDER BY created_at DESC""",
            (video_name,)
        )
        return cur.fetchall()

def get_feedback_ad_stats():
    # medias por vídeo y ranking
    with get_conn() as conn:
        cur = conn.execute("""
            SELECT
              video_name,
              COUNT(*) AS n,
              AVG(transcripcio)   AS avg_transcripcio,
              AVG(identificacio)  AS avg_identificacio,
              AVG(localitzacions) AS avg_localitzacions,
              AVG(activitats)     AS avg_activitats,
              AVG(narracions)     AS avg_narracions,
              AVG(expressivitat)  AS avg_expressivitat,
              (AVG(transcripcio)+AVG(identificacio)+AVG(localitzacions)+AVG(activitats)+AVG(narracions)+AVG(expressivitat))/6.0 AS avg_global
            FROM feedback_ad
            GROUP BY video_name
            ORDER BY avg_global DESC, n DESC;
        """)
        return cur.fetchall()
        
def now_str():
    return datetime.utcnow().isoformat(timespec="seconds") + "Z"

# Users
def create_user(username: str, password_hash: str, role: str):
    with get_conn() as conn:
        conn.execute(
            "INSERT INTO users(username, password_hash, role, created_at) VALUES (?,?,?,?)",
            (username, password_hash, role, now_str()),
        )

def get_user(username: str):
    with get_conn() as conn:
        cur = conn.execute("SELECT * FROM users WHERE username=?", (username,))
        return cur.fetchone()

def get_all_users() -> List[Dict[str, Any]]:
    with get_conn() as conn:
        cur = conn.execute("SELECT id, username, role FROM users ORDER BY username")
        return cur.fetchall()

def update_user_password(username: str, password_hash: str):
    with get_conn() as conn:
        conn.execute(
            "UPDATE users SET password_hash = ? WHERE username = ?",
            (password_hash, username)
        )

# Videos
def create_video(filename: str, original_name: str, uploader: str, status: str) -> int:
    with get_conn() as conn:
        cur = conn.execute(
            "INSERT INTO videos(filename, original_name, uploader, status, created_at) VALUES (?,?,?,?,?)",
            (filename, original_name, uploader, status, now_str()),
        )
        return cur.lastrowid

def update_video_status(video_id: int, status: str):
    with get_conn() as conn:
        conn.execute("UPDATE videos SET status=? WHERE id=?", (status, video_id))

def list_videos(limit: int = 200):
    with get_conn() as conn:
        cur = conn.execute(
            "SELECT * FROM videos ORDER BY id DESC LIMIT ?", (limit,)
        )
        return cur.fetchall()

def get_video(video_id: int):
    with get_conn() as conn:
        cur = conn.execute("SELECT * FROM videos WHERE id=?", (video_id,))
        return cur.fetchone()

# Results
def upsert_result(video_id: int, mode: str, text_path: str = None, srt_path: str = None,
                  mp3_path: str = None, characters_json: str = None, metrics_json: str = None):
    with get_conn() as conn:
        cur = conn.execute(
            "SELECT id FROM results WHERE video_id=? AND mode=?", (video_id, mode)
        )
        row = cur.fetchone()
        if row:
            conn.execute(
                "UPDATE results SET text_path=?, srt_path=?, mp3_path=?, characters_json=?, metrics_json=? WHERE id=?",
                (text_path, srt_path, mp3_path, characters_json, metrics_json, row["id"])
            )
        else:
            conn.execute(
                "INSERT INTO results(video_id, mode, text_path, srt_path, mp3_path, characters_json, metrics_json, created_at) VALUES (?,?,?,?,?,?,?,?)",
                (video_id, mode, text_path, srt_path, mp3_path, characters_json, metrics_json, now_str())
            )

def get_results(video_id: int):
    with get_conn() as conn:
        cur = conn.execute("SELECT * FROM results WHERE video_id=?", (video_id,))
        return cur.fetchall()

# Feedback
def add_feedback(video_id: int, user_id: int, clarity: int, sync: int, relevance: int,
                 naturalness: int, overall: int, comments: str):
    with get_conn() as conn:
        conn.execute(
            "INSERT INTO feedback(video_id, user_id, clarity, sync, relevance, naturalness, overall, comments, created_at) VALUES (?,?,?,?,?,?,?,?,?)",
            (video_id, user_id, clarity, sync, relevance, naturalness, overall, comments, now_str())
        )

def get_feedback_for_video(video_id: int):
    with get_conn() as conn:
        cur = conn.execute("SELECT * FROM feedback WHERE video_id=?", (video_id,))
        return cur.fetchall()

def get_feedback_stats():
    with get_conn() as conn:
        cur = conn.execute("""
        SELECT
          v.id as video_id,
          v.original_name as name,
          COUNT(f.id) as n,
          AVG(f.overall) as overall_avg,
          AVG(f.clarity) as clarity_avg,
          AVG(f.sync) as sync_avg,
          AVG(f.relevance) as relevance_avg,
          AVG(f.naturalness) as naturalness_avg
        FROM videos v
        LEFT JOIN feedback f ON f.video_id = v.id
        GROUP BY v.id
        ORDER BY overall_avg DESC NULLS LAST, n DESC, v.id DESC
        """)
        return cur.fetchall()


def get_feedback_with_users():
    with get_conn() as conn:
        cur = conn.execute("""
        SELECT f.*, u.role as user_role
        FROM feedback f
        JOIN users u ON u.id = f.user_id
        """)
        return cur.fetchall()

def get_feedback_stats_weighted(role_weights: Dict[str, float] = None):
    role_weights = role_weights or {'verd':1.0,'groc':1.0,'taronja':0.0,'blau':1.5}
    # Aggregate in Python to apply weights
    with get_conn() as conn:
        # Bring minimal info to Python for weighting
        cur = conn.execute("""
        SELECT v.id as video_id, v.original_name as name FROM videos v
        """)
        videos = cur.fetchall()

        # Pull feedback + roles
        cur = conn.execute("""
        SELECT f.video_id, f.clarity, f.sync, f.relevance, f.naturalness, f.overall, u.role as user_role
        FROM feedback f
        JOIN users u ON u.id = f.user_id
        """)
        fb = cur.fetchall()

    by_vid = {v["video_id"]: {"name": v["name"], "n":0, "w_sum":0.0,
                              "overall":0.0,"clarity":0.0,"sync":0.0,"relevance":0.0,"naturalness":0.0}
              for v in videos}
    for r in fb:
        w = role_weights.get(r["user_role"], 0.0)
        if r["video_id"] not in by_vid:  # safety
            continue
        by_vid[r["video_id"]]["n"] += 1
        by_vid[r["video_id"]]["w_sum"] += w
        by_vid[r["video_id"]]["overall"] += w * r["overall"]
        by_vid[r["video_id"]]["clarity"] += w * r["clarity"]
        by_vid[r["video_id"]]["sync"] += w * r["sync"]
        by_vid[r["video_id"]]["relevance"] += w * r["relevance"]
        by_vid[r["video_id"]]["naturalness"] += w * r["naturalness"]

    # Build result rows with weighted averages
    rows = []
    for vid, agg in by_vid.items():
        w = agg["w_sum"] if agg["w_sum"]>0 else None
        def avg(val): 
            return (val / w) if w else None
        rows.append({
            "video_id": vid,
            "name": agg["name"],
            "n_ratings": agg["n"],
            "w_count": agg["w_sum"],
            "overall_avg_w": avg(agg["overall"]),
            "clarity_avg_w": avg(agg["clarity"]),
            "sync_avg_w": avg(agg["sync"]),
            "relevance_avg_w": avg(agg["relevance"]),
            "naturalness_avg_w": avg(agg["naturalness"]),
        })
    # Sort: by weighted overall desc, then n_ratings desc
    rows.sort(key=lambda r: (r["overall_avg_w"] is None, -(r["overall_avg_w"] or 0), -r["n_ratings"], -r["w_count"]))
    return rows