"""완료 작업 이력 DB.

작업의 비용, 소요시간, 토큰 사용량을 SQLite에 기록한다.
"""
from __future__ import annotations

import logging
import os

import aiosqlite

logger = logging.getLogger(__name__)

_CREATE_TABLE = """
CREATE TABLE IF NOT EXISTS task_history (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    task_id TEXT UNIQUE NOT NULL,
    thread_id TEXT NOT NULL,
    issue_number INTEGER NOT NULL DEFAULT 0,
    repo_name TEXT NOT NULL DEFAULT '',
    source TEXT NOT NULL DEFAULT '',
    status TEXT NOT NULL,
    created_at TEXT NOT NULL,
    completed_at TEXT NOT NULL,
    duration_seconds REAL NOT NULL DEFAULT 0,
    tokens_input INTEGER NOT NULL DEFAULT 0,
    tokens_output INTEGER NOT NULL DEFAULT 0,
    cost_usd REAL NOT NULL DEFAULT 0,
    error_message TEXT NOT NULL DEFAULT ''
)
"""


class TaskHistory:
    def __init__(self, db_path: str = "/data/task_history.db"):
        self._db_path = db_path
        self._db: aiosqlite.Connection | None = None

    async def initialize(self) -> None:
        self._db = await aiosqlite.connect(self._db_path)
        self._db.row_factory = aiosqlite.Row
        await self._db.execute(_CREATE_TABLE)
        await self._db.commit()

    async def close(self) -> None:
        if self._db:
            await self._db.close()

    async def record(
        self, task_id: str, thread_id: str, issue_number: int, repo_name: str,
        source: str, status: str, created_at: str, completed_at: str,
        duration_seconds: float, tokens_input: int, tokens_output: int,
        cost_usd: float, error_message: str = "",
    ) -> None:
        await self._db.execute(
            "INSERT OR REPLACE INTO task_history "
            "(task_id, thread_id, issue_number, repo_name, source, status, "
            "created_at, completed_at, duration_seconds, tokens_input, tokens_output, "
            "cost_usd, error_message) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)",
            (task_id, thread_id, issue_number, repo_name, source, status,
             created_at, completed_at, duration_seconds, tokens_input, tokens_output,
             cost_usd, error_message),
        )
        await self._db.commit()
        logger.info("Recorded history: task=%s status=%s cost=$%.4f", task_id, status, cost_usd)

    async def get_recent(self, limit: int = 20) -> list[dict]:
        cursor = await self._db.execute(
            "SELECT * FROM task_history ORDER BY completed_at DESC LIMIT ?", (limit,),
        )
        rows = await cursor.fetchall()
        return [dict(row) for row in rows]


_history: TaskHistory | None = None


async def get_task_history() -> TaskHistory:
    global _history
    if _history is None:
        db_path = os.environ.get("TASK_HISTORY_DB", "/data/task_history.db")
        _history = TaskHistory(db_path=db_path)
        await _history.initialize()
    return _history