"""
generation_db.py
================

SQLite persistence for ComfyUI generation history and output file blobs.

Two tables
----------
generation_history : one row per prompt submitted to ComfyUI
generation_files   : one row per output file (image / video) as a BLOB

The module-level ``_DB_PATH`` is set by :func:`init_db`; all other
functions use that path so callers never need to pass it around.
"""

from __future__ import annotations

import json
import secrets
import sqlite3
from datetime import datetime, timezone
from pathlib import Path
from typing import Any

_DB_PATH: Path = Path(__file__).parent / "generation_history.db"

_SCHEMA = """
CREATE TABLE IF NOT EXISTS generation_history (
    id          INTEGER PRIMARY KEY AUTOINCREMENT,
    prompt_id   TEXT UNIQUE NOT NULL,
    source      TEXT NOT NULL,
    user_label  TEXT,
    overrides   TEXT,
    seed        INTEGER,
    created_at  TEXT NOT NULL
);

CREATE TABLE IF NOT EXISTS generation_files (
    id              INTEGER PRIMARY KEY AUTOINCREMENT,
    generation_id   INTEGER NOT NULL REFERENCES generation_history(id),
    filename        TEXT NOT NULL,
    file_data       BLOB NOT NULL,
    mime_type       TEXT
);

CREATE TABLE IF NOT EXISTS generation_shares (
    id          INTEGER PRIMARY KEY AUTOINCREMENT,
    share_token TEXT UNIQUE NOT NULL,
    prompt_id   TEXT NOT NULL,
    owner_label TEXT NOT NULL,
    created_at  TEXT NOT NULL
);
"""


def _connect(db_path: Path | None = None) -> sqlite3.Connection:
    path = db_path if db_path is not None else _DB_PATH
    conn = sqlite3.connect(str(path), check_same_thread=False)
    conn.row_factory = sqlite3.Row
    return conn


def _detect_mime(data: bytes) -> str:
    """Detect MIME type from magic bytes."""
    if data[:8] == b"\x89PNG\r\n\x1a\n":
        return "image/png"
    if data[:2] == b"\xff\xd8":
        return "image/jpeg"
    if len(data) >= 12 and data[:4] == b"RIFF" and data[8:12] == b"WEBP":
        return "image/webp"
    if len(data) >= 12 and data[:4] == b"RIFF" and data[8:12] == b"AVI ":
        return "video/x-msvideo"
    if len(data) >= 8 and data[4:8] == b"ftyp":
        return "video/mp4"
    if data[:4] == b"\x1aE\xdf\xa3":  # EBML (WebM/MKV)
        return "video/webm"
    return "application/octet-stream"


def init_db(db_path: Path = _DB_PATH) -> None:
    """Create tables if they don't exist. Accepts a path for testability."""
    global _DB_PATH
    _DB_PATH = db_path
    with _connect(db_path) as conn:
        conn.executescript(_SCHEMA)
        conn.commit()


def record_generation(
    prompt_id: str,
    source: str,
    user_label: str | None,
    overrides_dict: dict[str, Any] | None,
    seed: int | None,
) -> int:
    """Insert a generation history row. Returns the auto-increment ``id``."""
    overrides_json = json.dumps(overrides_dict) if overrides_dict is not None else None
    created_at = datetime.now(timezone.utc).isoformat()
    with _connect() as conn:
        cur = conn.execute(
            """
            INSERT INTO generation_history
                (prompt_id, source, user_label, overrides, seed, created_at)
            VALUES (?, ?, ?, ?, ?, ?)
            """,
            (prompt_id, source, user_label, overrides_json, seed, created_at),
        )
        conn.commit()
        return cur.lastrowid  # type: ignore[return-value]


def record_file(generation_id: int, filename: str, file_data: bytes) -> None:
    """Insert a file BLOB row, auto-detecting MIME type from magic bytes."""
    mime_type = _detect_mime(file_data)
    with _connect() as conn:
        conn.execute(
            """
            INSERT INTO generation_files (generation_id, filename, file_data, mime_type)
            VALUES (?, ?, ?, ?)
            """,
            (generation_id, filename, file_data, mime_type),
        )
        conn.commit()


def _rows_to_history(conn: sqlite3.Connection, rows) -> list[dict]:
    """Convert raw generation_history rows (with optional share_token) to dicts."""
    result: list[dict] = []
    for row in rows:
        d = dict(row)
        if d["overrides"]:
            try:
                d["overrides"] = json.loads(d["overrides"])
            except (json.JSONDecodeError, TypeError):
                d["overrides"] = {}
        else:
            d["overrides"] = {}

        files = conn.execute(
            "SELECT filename FROM generation_files WHERE generation_id = ?",
            (d["id"],),
        ).fetchall()
        d["file_paths"] = [f["filename"] for f in files]
        result.append(d)
    return result


def get_history(limit: int = 50) -> list[dict]:
    """Return recent generation rows (newest first) with a ``file_paths`` list."""
    with _connect() as conn:
        rows = conn.execute(
            """
            SELECT h.id, h.prompt_id, h.source, h.user_label, h.overrides, h.seed, h.created_at,
                   s.share_token
            FROM generation_history h
            LEFT JOIN generation_shares s ON h.prompt_id = s.prompt_id AND s.owner_label = h.user_label
            ORDER BY h.id DESC LIMIT ?
            """,
            (limit,),
        ).fetchall()
        return _rows_to_history(conn, rows)


def get_history_for_user(user_label: str, limit: int = 50) -> list[dict]:
    """Return recent generation rows for a specific user (newest first)."""
    with _connect() as conn:
        rows = conn.execute(
            """
            SELECT h.id, h.prompt_id, h.source, h.user_label, h.overrides, h.seed, h.created_at,
                   s.share_token
            FROM generation_history h
            LEFT JOIN generation_shares s ON h.prompt_id = s.prompt_id AND s.owner_label = ?
            WHERE h.user_label = ?
            ORDER BY h.id DESC LIMIT ?
            """,
            (user_label, user_label, limit),
        ).fetchall()
        return _rows_to_history(conn, rows)


def get_generation(prompt_id: str) -> dict | None:
    """Return the generation_history row for *prompt_id*, or None."""
    with _connect() as conn:
        row = conn.execute(
            "SELECT id, prompt_id, user_label FROM generation_history WHERE prompt_id = ?",
            (prompt_id,),
        ).fetchone()
        return dict(row) if row else None


def get_generation_full(prompt_id: str) -> dict | None:
    """Return overrides (parsed) + seed for *prompt_id*, or None if not found."""
    with _connect() as conn:
        row = conn.execute(
            "SELECT prompt_id, user_label, overrides, seed FROM generation_history WHERE prompt_id = ?",
            (prompt_id,),
        ).fetchone()
        if row is None:
            return None
        d = dict(row)
        if d["overrides"]:
            try:
                d["overrides"] = json.loads(d["overrides"])
            except (json.JSONDecodeError, TypeError):
                d["overrides"] = {}
        else:
            d["overrides"] = {}
        return d


def search_history_for_user(user_label: str, query: str, limit: int = 50) -> list[dict]:
    """Return history rows where the overrides JSON contains *query* (case-insensitive)."""
    with _connect() as conn:
        rows = conn.execute(
            """
            SELECT h.id, h.prompt_id, h.source, h.user_label, h.overrides, h.seed, h.created_at,
                   s.share_token
            FROM generation_history h
            LEFT JOIN generation_shares s ON h.prompt_id = s.prompt_id AND s.owner_label = ?
            WHERE h.user_label = ? AND LOWER(h.overrides) LIKE LOWER(?)
            ORDER BY h.id DESC LIMIT ?
            """,
            (user_label, user_label, f"%{query}%", limit),
        ).fetchall()
        return _rows_to_history(conn, rows)


def search_history(query: str, limit: int = 50) -> list[dict]:
    """Admin version: search all users' history for *query* in overrides JSON."""
    with _connect() as conn:
        rows = conn.execute(
            """
            SELECT h.id, h.prompt_id, h.source, h.user_label, h.overrides, h.seed, h.created_at,
                   s.share_token
            FROM generation_history h
            LEFT JOIN generation_shares s ON h.prompt_id = s.prompt_id AND s.owner_label = h.user_label
            WHERE LOWER(h.overrides) LIKE LOWER(?)
            ORDER BY h.id DESC LIMIT ?
            """,
            (f"%{query}%", limit),
        ).fetchall()
        return _rows_to_history(conn, rows)


def create_share(prompt_id: str, owner_label: str) -> str:
    """Create a share token for *prompt_id*. Idempotent — returns the same token if one exists."""
    token = secrets.token_urlsafe(32)
    created_at = datetime.now(timezone.utc).isoformat()
    with _connect() as conn:
        conn.execute(
            """
            INSERT OR IGNORE INTO generation_shares (share_token, prompt_id, owner_label, created_at)
            VALUES (?, ?, ?, ?)
            """,
            (token, prompt_id, owner_label, created_at),
        )
        conn.commit()
        row = conn.execute(
            "SELECT share_token FROM generation_shares WHERE prompt_id = ? AND owner_label = ?",
            (prompt_id, owner_label),
        ).fetchone()
        return row["share_token"]


def revoke_share(prompt_id: str, owner_label: str) -> bool:
    """Delete the share token for *prompt_id*. Returns True if a row was deleted."""
    with _connect() as conn:
        cur = conn.execute(
            "DELETE FROM generation_shares WHERE prompt_id = ? AND owner_label = ?",
            (prompt_id, owner_label),
        )
        conn.commit()
        return cur.rowcount > 0


def get_share_by_token(token: str) -> dict | None:
    """Return generation info for a share token, or None if not found/revoked."""
    with _connect() as conn:
        row = conn.execute(
            """
            SELECT h.prompt_id, h.overrides, h.seed, h.created_at
            FROM generation_shares s
            JOIN generation_history h ON h.prompt_id = s.prompt_id
            WHERE s.share_token = ?
            """,
            (token,),
        ).fetchone()
        if row is None:
            return None
        d = dict(row)
        if d["overrides"]:
            try:
                d["overrides"] = json.loads(d["overrides"])
            except (json.JSONDecodeError, TypeError):
                d["overrides"] = {}
        else:
            d["overrides"] = {}
        return d


def get_files(prompt_id: str) -> list[dict]:
    """Return all output files for *prompt_id* as ``[{filename, data, mime_type}]``."""
    with _connect() as conn:
        gen_row = conn.execute(
            "SELECT id FROM generation_history WHERE prompt_id = ?",
            (prompt_id,),
        ).fetchone()
        if not gen_row:
            return []

        files = conn.execute(
            "SELECT filename, file_data, mime_type FROM generation_files WHERE generation_id = ?",
            (gen_row["id"],),
        ).fetchall()
        return [
            {
                "filename": f["filename"],
                "data": bytes(f["file_data"]),
                "mime_type": f["mime_type"],
            }
            for f in files
        ]