"""Database operations for API key management.

Supports PostgreSQL (via DATABASE_URL) with SQLite fallback for local dev.
"""
import os
import sqlite3
import logging
from contextlib import contextmanager
from datetime import datetime, timezone

logger = logging.getLogger(__name__)

DATABASE_URL = os.getenv("DATABASE_URL", "")
DB_PATH = os.getenv("DB_PATH", "/tmp/data/tavily_keys.db")

_use_pg = bool(DATABASE_URL)

if _use_pg:
    import psycopg2
    import psycopg2.extras


def _ensure_dir():
    if not _use_pg:
        os.makedirs(os.path.dirname(DB_PATH), exist_ok=True)


@contextmanager
def get_db():
    if _use_pg:
        conn = psycopg2.connect(DATABASE_URL)
        conn.autocommit = False
        try:
            yield conn
            conn.commit()
        except Exception:
            conn.rollback()
            raise
        finally:
            conn.close()
    else:
        _ensure_dir()
        conn = sqlite3.connect(DB_PATH)
        conn.row_factory = sqlite3.Row
        conn.execute("PRAGMA journal_mode=WAL")
        try:
            yield conn
            conn.commit()
        except Exception:
            conn.rollback()
            raise
        finally:
            conn.close()


def _execute(conn, sql, params=None):
    if _use_pg:
        cur = conn.cursor(cursor_factory=psycopg2.extras.RealDictCursor)
    else:
        cur = conn.cursor()
    cur.execute(sql, params or ())
    return cur


def _fetchall(conn, sql, params=None):
    cur = _execute(conn, sql, params)
    rows = cur.fetchall()
    return [dict(r) for r in rows]


def _fetchone(conn, sql, params=None):
    cur = _execute(conn, sql, params)
    row = cur.fetchone()
    if row is None:
        return None
    return dict(row)


def _sql(template):
    """Convert SQL template: replace ? with %s for PostgreSQL."""
    if _use_pg:
        return template.replace("?", "%s")
    return template


# ── Initialization ──

def init_db():
    with get_db() as conn:
        if _use_pg:
            _execute(conn, """
                CREATE TABLE IF NOT EXISTS api_keys (
                    id SERIAL PRIMARY KEY,
                    email TEXT NOT NULL,
                    password TEXT DEFAULT '',
                    api_key TEXT NOT NULL UNIQUE,
                    service TEXT DEFAULT 'tavily',
                    status TEXT DEFAULT 'active',
                    created_at TEXT NOT NULL,
                    last_checked TEXT,
                    quota_remaining INTEGER,
                    use_count INTEGER DEFAULT 0
                )
            """)
            _execute(conn, """
                CREATE TABLE IF NOT EXISTS meta (
                    key TEXT PRIMARY KEY,
                    value TEXT
                )
            """)
            _execute(conn, """
                CREATE TABLE IF NOT EXISTS access_tokens (
                    id SERIAL PRIMARY KEY,
                    token TEXT NOT NULL UNIQUE,
                    name TEXT DEFAULT '',
                    quota_limit INTEGER DEFAULT 1000,
                    quota_used INTEGER DEFAULT 0,
                    is_admin BOOLEAN DEFAULT FALSE,
                    status TEXT DEFAULT 'active',
                    created_at TEXT NOT NULL,
                    last_used TEXT,
                    expires_at TEXT
                )
            """)
            _execute(conn, """
                CREATE TABLE IF NOT EXISTS config (
                    key TEXT PRIMARY KEY,
                    value TEXT NOT NULL
                )
            """)
        else:
            _execute(conn, """
                CREATE TABLE IF NOT EXISTS api_keys (
                    id INTEGER PRIMARY KEY AUTOINCREMENT,
                    email TEXT NOT NULL,
                    password TEXT DEFAULT '',
                    api_key TEXT NOT NULL UNIQUE,
                    service TEXT DEFAULT 'tavily',
                    status TEXT DEFAULT 'active',
                    created_at TEXT NOT NULL,
                    last_checked TEXT,
                    quota_remaining INTEGER,
                    use_count INTEGER DEFAULT 0
                )
            """)
            _execute(conn, """
                CREATE TABLE IF NOT EXISTS meta (
                    key TEXT PRIMARY KEY,
                    value TEXT
                )
            """)
            _execute(conn, """
                CREATE TABLE IF NOT EXISTS access_tokens (
                    id INTEGER PRIMARY KEY AUTOINCREMENT,
                    token TEXT NOT NULL UNIQUE,
                    name TEXT DEFAULT '',
                    quota_limit INTEGER DEFAULT 1000,
                    quota_used INTEGER DEFAULT 0,
                    is_admin INTEGER DEFAULT 0,
                    status TEXT DEFAULT 'active',
                    created_at TEXT NOT NULL,
                    last_used TEXT,
                    expires_at TEXT
                )
            """)
            _execute(conn, """
                CREATE TABLE IF NOT EXISTS config (
                    key TEXT PRIMARY KEY,
                    value TEXT NOT NULL
                )
            """)

    # Migrations
    for col, coltype, default in [
        ("use_count", "INTEGER", "0"),
        ("quota_remaining", "INTEGER", "NULL"),
        ("service", "TEXT", "'tavily'"),
    ]:
        try:
            with get_db() as conn:
                if _use_pg:
                    _execute(conn, f"ALTER TABLE api_keys ADD COLUMN IF NOT EXISTS {col} {coltype} DEFAULT {default}")
                else:
                    _execute(conn, f"ALTER TABLE api_keys ADD COLUMN {col} {coltype} DEFAULT {default}")
        except Exception:
            pass

    for tbl, col, coltype, default in [("access_tokens", "expires_at", "TEXT", "NULL")]:
        try:
            with get_db() as conn:
                if _use_pg:
                    _execute(conn, f"ALTER TABLE {tbl} ADD COLUMN IF NOT EXISTS {col} {coltype} DEFAULT {default}")
                else:
                    _execute(conn, f"ALTER TABLE {tbl} ADD COLUMN {col} {coltype} DEFAULT {default}")
        except Exception:
            pass

    _seed_defaults()
    db_type = "PostgreSQL" if _use_pg else f"SQLite ({DB_PATH})"
    logger.info("Database initialized: %s", db_type)


def _seed_defaults():
    """Seed default config values and admin token if not present."""
    defaults = {
        "admin_password": os.getenv("ADMIN_PASSWORD", ""),
        "admin_token": os.getenv("ADMIN_TOKEN", ""),
        "free_mode": os.getenv("FREE_MODE", "false"),
        "default_quota": os.getenv("DEFAULT_QUOTA", "1000"),
    }
    with get_db() as conn:
        for k, v in defaults.items():
            existing = _fetchone(conn, _sql("SELECT value FROM config WHERE key = ?"), (k,))
            if not existing:
                if _use_pg:
                    _execute(conn, "INSERT INTO config (key, value) VALUES (%s, %s) ON CONFLICT (key) DO NOTHING", (k, v))
                else:
                    _execute(conn, "INSERT OR IGNORE INTO config (key, value) VALUES (?, ?)", (k, v))

    # Ensure admin token exists
    admin_token = get_config("admin_token")
    if admin_token:
        with get_db() as conn:
            existing = _fetchone(conn, _sql("SELECT id FROM access_tokens WHERE token = ?"), (admin_token,))
            if not existing:
                now = datetime.now(timezone.utc).isoformat()
                if _use_pg:
                    _execute(conn,
                        "INSERT INTO access_tokens (token, name, quota_limit, quota_used, is_admin, status, created_at) "
                        "VALUES (%s, %s, %s, %s, %s, %s, %s) ON CONFLICT (token) DO NOTHING",
                        (admin_token, "Admin", 0, 0, True, "active", now))
                else:
                    _execute(conn,
                        "INSERT OR IGNORE INTO access_tokens (token, name, quota_limit, quota_used, is_admin, status, created_at) "
                        "VALUES (?, ?, ?, ?, ?, ?, ?)",
                        (admin_token, "Admin", 0, 0, 1, "active", now))


# ── API Key CRUD ──

def add_key(email: str, password: str, api_key: str, created_at: str = "",
            service: str = "tavily") -> int:
    if not created_at:
        created_at = datetime.now(timezone.utc).isoformat()
    with get_db() as conn:
        if _use_pg:
            cur = _execute(conn,
                "INSERT INTO api_keys (email, password, api_key, service, created_at) "
                "VALUES (%s, %s, %s, %s, %s) RETURNING id",
                (email, password, api_key, service, created_at))
            return cur.fetchone()["id"]
        else:
            cur = _execute(conn,
                "INSERT INTO api_keys (email, password, api_key, service, created_at) "
                "VALUES (?, ?, ?, ?, ?)",
                (email, password, api_key, service, created_at))
            return cur.lastrowid


def add_keys_batch(keys: list[dict]) -> int:
    added = 0
    with get_db() as conn:
        for k in keys:
            try:
                created = k.get("created_at", datetime.now(timezone.utc).isoformat())
                svc = k.get("service") or "tavily"
                if _use_pg:
                    cur = _execute(conn,
                        "INSERT INTO api_keys (email, password, api_key, service, created_at) "
                        "VALUES (%s, %s, %s, %s, %s) ON CONFLICT (api_key) DO NOTHING",
                        (k["email"], k.get("password", ""), k["api_key"], svc, created))
                else:
                    cur = _execute(conn,
                        "INSERT OR IGNORE INTO api_keys (email, password, api_key, service, created_at) "
                        "VALUES (?, ?, ?, ?, ?)",
                        (k["email"], k.get("password", ""), k["api_key"], svc, created))
                added += int(bool(cur.rowcount))
            except Exception:
                pass
    return added


def list_keys(status: str = "", service: str = "") -> list[dict]:
    with get_db() as conn:
        conditions, params = [], []
        if status:
            conditions.append("status = ?")
            params.append(status)
        if service:
            conditions.append("service = ?")
            params.append(service)
        where = (" WHERE " + " AND ".join(conditions)) if conditions else ""
        return _fetchall(conn, _sql(f"SELECT * FROM api_keys{where} ORDER BY id DESC"), tuple(params))


def get_key(key_id: int) -> dict | None:
    with get_db() as conn:
        return _fetchone(conn, _sql("SELECT * FROM api_keys WHERE id = ?"), (key_id,))


def delete_key(key_id: int) -> bool:
    with get_db() as conn:
        cur = _execute(conn, _sql("DELETE FROM api_keys WHERE id = ?"), (key_id,))
        return cur.rowcount > 0


def delete_keys_batch(key_ids: list[int]) -> int:
    if not key_ids:
        return 0
    with get_db() as conn:
        if _use_pg:
            cur = _execute(conn, "DELETE FROM api_keys WHERE id = ANY(%s)", (key_ids,))
        else:
            placeholders = ",".join("?" for _ in key_ids)
            cur = _execute(conn, f"DELETE FROM api_keys WHERE id IN ({placeholders})", tuple(key_ids))
        return cur.rowcount


def delete_keys_by_status(statuses: list[str]) -> int:
    if not statuses:
        return 0
    with get_db() as conn:
        if _use_pg:
            placeholders = ",".join("%s" for _ in statuses)
        else:
            placeholders = ",".join("?" for _ in statuses)
        cur = _execute(conn,
            f"DELETE FROM api_keys WHERE status IN ({placeholders})", tuple(statuses))
        return cur.rowcount


def update_status(key_id: int, status: str, quota_remaining: int | None = None):
    now = datetime.now(timezone.utc).isoformat()
    with get_db() as conn:
        if quota_remaining is not None:
            _execute(conn, _sql(
                "UPDATE api_keys SET status = ?, last_checked = ?, quota_remaining = ? WHERE id = ?"
            ), (status, now, quota_remaining, key_id))
        else:
            _execute(conn, _sql(
                "UPDATE api_keys SET status = ?, last_checked = ? WHERE id = ?"
            ), (status, now, key_id))


def update_status_batch(key_ids: list[int], status: str) -> int:
    if not key_ids:
        return 0
    now = datetime.now(timezone.utc).isoformat()
    with get_db() as conn:
        if _use_pg:
            cur = _execute(conn,
                "UPDATE api_keys SET status = %s, last_checked = %s WHERE id = ANY(%s)",
                (status, now, key_ids))
        else:
            placeholders = ",".join("?" for _ in key_ids)
            cur = _execute(conn,
                f"UPDATE api_keys SET status = ?, last_checked = ? WHERE id IN ({placeholders})",
                (status, now, *key_ids))
        return cur.rowcount


def get_next_active_key(service: str = "tavily") -> dict | None:
    """Get the least-recently-checked active key for a service (round-robin) and increment use_count."""
    with get_db() as conn:
        row = _fetchone(conn, _sql(
            "SELECT * FROM api_keys WHERE status = 'active' AND service = ? "
            "ORDER BY last_checked ASC NULLS FIRST LIMIT 1"), (service,))
        if row:
            now = datetime.now(timezone.utc).isoformat()
            _execute(conn, _sql(
                "UPDATE api_keys SET last_checked = ?, use_count = COALESCE(use_count, 0) + 1 WHERE id = ?"
            ), (now, row["id"]))
            return row
        return None


def get_stats() -> dict:
    with get_db() as conn:
        total = _fetchone(conn, "SELECT COUNT(*) as cnt FROM api_keys")["cnt"]
        active = _fetchone(conn, "SELECT COUNT(*) as cnt FROM api_keys WHERE status='active'")["cnt"]
        inactive = _fetchone(conn, "SELECT COUNT(*) as cnt FROM api_keys WHERE status='inactive'")["cnt"]
        exhausted = _fetchone(conn, "SELECT COUNT(*) as cnt FROM api_keys WHERE status='exhausted'")["cnt"]
        total_usage = _fetchone(conn, "SELECT COALESCE(SUM(use_count), 0) as cnt FROM api_keys")["cnt"]
        quota_sum = _fetchone(conn,
            "SELECT COALESCE(SUM(quota_remaining), 0) as cnt FROM api_keys "
            "WHERE status='active' AND quota_remaining IS NOT NULL")["cnt"]
        last_reg = _fetchone(conn, "SELECT created_at FROM api_keys ORDER BY id DESC LIMIT 1")
        last_check = _fetchone(conn, "SELECT value FROM meta WHERE key='last_healthcheck'")

        by_service = {}
        for svc in ("tavily", "firecrawl", "exa"):
            s_total = _fetchone(conn, _sql("SELECT COUNT(*) as cnt FROM api_keys WHERE service = ?"), (svc,))["cnt"]
            if s_total == 0:
                continue
            s_active = _fetchone(conn, _sql("SELECT COUNT(*) as cnt FROM api_keys WHERE service = ? AND status='active'"), (svc,))["cnt"]
            s_inactive = _fetchone(conn, _sql("SELECT COUNT(*) as cnt FROM api_keys WHERE service = ? AND status='inactive'"), (svc,))["cnt"]
            s_exhausted = _fetchone(conn, _sql("SELECT COUNT(*) as cnt FROM api_keys WHERE service = ? AND status='exhausted'"), (svc,))["cnt"]
            s_usage = _fetchone(conn, _sql("SELECT COALESCE(SUM(use_count), 0) as cnt FROM api_keys WHERE service = ?"), (svc,))["cnt"]
            s_quota = _fetchone(conn, _sql(
                "SELECT COALESCE(SUM(quota_remaining), 0) as cnt FROM api_keys "
                "WHERE service = ? AND status='active' AND quota_remaining IS NOT NULL"), (svc,))["cnt"]
            by_service[svc] = {
                "total_keys": s_total, "active_keys": s_active,
                "inactive_keys": s_inactive, "exhausted_keys": s_exhausted,
                "total_usage": s_usage,
                "total_quota_remaining": s_quota if s_quota else None,
            }

        return {
            "total_keys": total,
            "active_keys": active,
            "inactive_keys": inactive,
            "exhausted_keys": exhausted,
            "total_usage": total_usage,
            "total_quota_remaining": quota_sum if quota_sum else None,
            "last_registration": last_reg["created_at"] if last_reg else None,
            "last_healthcheck": last_check["value"] if last_check else None,
            "by_service": by_service,
        }


def set_meta(key: str, value: str):
    with get_db() as conn:
        if _use_pg:
            _execute(conn,
                "INSERT INTO meta (key, value) VALUES (%s, %s) "
                "ON CONFLICT (key) DO UPDATE SET value = EXCLUDED.value",
                (key, value))
        else:
            _execute(conn, "INSERT OR REPLACE INTO meta (key, value) VALUES (?, ?)", (key, value))


def export_all_keys() -> list[dict]:
    with get_db() as conn:
        return _fetchall(conn,
            "SELECT email, password, api_key, service, status, created_at, last_checked, "
            "COALESCE(use_count, 0) as use_count FROM api_keys ORDER BY id")


# ── Access Token CRUD ──

def add_access_token(token: str, name: str = "", quota_limit: int = 1000,
                     is_admin: bool = False, expires_at: str | None = None) -> int:
    now = datetime.now(timezone.utc).isoformat()
    with get_db() as conn:
        if _use_pg:
            cur = _execute(conn,
                "INSERT INTO access_tokens (token, name, quota_limit, is_admin, status, created_at, expires_at) "
                "VALUES (%s, %s, %s, %s, %s, %s, %s) RETURNING id",
                (token, name, quota_limit, is_admin, "active", now, expires_at))
            return cur.fetchone()["id"]
        else:
            cur = _execute(conn,
                "INSERT INTO access_tokens (token, name, quota_limit, is_admin, status, created_at, expires_at) "
                "VALUES (?, ?, ?, ?, ?, ?, ?)",
                (token, name, quota_limit, 1 if is_admin else 0, "active", now, expires_at))
            return cur.lastrowid


def list_access_tokens() -> list[dict]:
    with get_db() as conn:
        rows = _fetchall(conn, "SELECT * FROM access_tokens ORDER BY id")
        for r in rows:
            r["is_admin"] = bool(r.get("is_admin"))
        return rows


def get_access_token(token: str) -> dict | None:
    with get_db() as conn:
        row = _fetchone(conn, _sql("SELECT * FROM access_tokens WHERE token = ? AND status = 'active'"), (token,))
        if row:
            row["is_admin"] = bool(row.get("is_admin"))
            exp = row.get("expires_at")
            if exp:
                try:
                    if datetime.fromisoformat(exp.replace("Z", "+00:00")) < datetime.now(timezone.utc):
                        return None
                except ValueError:
                    pass
        return row


def delete_access_token(token_id: int) -> bool:
    with get_db() as conn:
        cur = _execute(conn, _sql("DELETE FROM access_tokens WHERE id = ?"), (token_id,))
        return cur.rowcount > 0


def update_access_token(token_id: int, **kwargs) -> bool:
    allowed = {"name", "quota_limit", "status", "expires_at"}
    updates = {k: v for k, v in kwargs.items() if k in allowed}
    if not updates:
        return False
    with get_db() as conn:
        if _use_pg:
            set_clause = ", ".join(f"{k} = %s" for k in updates)
            _execute(conn, f"UPDATE access_tokens SET {set_clause} WHERE id = %s",
                     (*updates.values(), token_id))
        else:
            set_clause = ", ".join(f"{k} = ?" for k in updates)
            _execute(conn, f"UPDATE access_tokens SET {set_clause} WHERE id = ?",
                     (*updates.values(), token_id))
        return True


def increment_token_usage(token: str) -> bool:
    now = datetime.now(timezone.utc).isoformat()
    with get_db() as conn:
        cur = _execute(conn, _sql(
            "UPDATE access_tokens SET quota_used = quota_used + 1, last_used = ? WHERE token = ?"),
            (now, token))
        return cur.rowcount > 0


def reset_token_usage(token_id: int) -> bool:
    with get_db() as conn:
        cur = _execute(conn, _sql("UPDATE access_tokens SET quota_used = 0 WHERE id = ?"), (token_id,))
        return cur.rowcount > 0


# ── Config ──

def get_config(key: str) -> str | None:
    with get_db() as conn:
        row = _fetchone(conn, _sql("SELECT value FROM config WHERE key = ?"), (key,))
        return row["value"] if row else None


def set_config(key: str, value: str):
    with get_db() as conn:
        if _use_pg:
            _execute(conn,
                "INSERT INTO config (key, value) VALUES (%s, %s) "
                "ON CONFLICT (key) DO UPDATE SET value = EXCLUDED.value",
                (key, value))
        else:
            _execute(conn, "INSERT OR REPLACE INTO config (key, value) VALUES (?, ?)", (key, value))


def get_all_config() -> dict:
    with get_db() as conn:
        rows = _fetchall(conn, "SELECT key, value FROM config ORDER BY key")
        return {r["key"]: r["value"] for r in rows}