import json
import os
import sqlite3
import time
import uuid


DEFAULT_DB_PATH = "/var/lib/recipe/metrics.sqlite3"


def db_path() -> str:
    return os.environ.get("RECIPE_METRICS_DB", DEFAULT_DB_PATH)


def initialize() -> None:
    path = db_path()
    os.makedirs(os.path.dirname(path), exist_ok=True)
    with sqlite3.connect(path) as connection:
        connection.execute("PRAGMA journal_mode=WAL")
        connection.execute("""
            CREATE TABLE IF NOT EXISTS requests (
                request_id TEXT PRIMARY KEY,
                started_at TEXT NOT NULL,
                client_ip TEXT,
                user_agent TEXT,
                method TEXT NOT NULL,
                path TEXT NOT NULL,
                image_mime TEXT,
                image_bytes INTEGER,
                prompt_chars INTEGER,
                status_code INTEGER NOT NULL,
                duration_ms INTEGER NOT NULL,
                response_bytes INTEGER,
                usage_json TEXT,
                error TEXT
            )
        """)
        connection.execute("CREATE INDEX IF NOT EXISTS idx_requests_started_at ON requests(started_at)")
        connection.execute("CREATE INDEX IF NOT EXISTS idx_requests_status_code ON requests(status_code)")
        connection.execute(
            "CREATE INDEX IF NOT EXISTS idx_requests_client_ip_started_at ON requests(client_ip, started_at)"
        )


def record(**values) -> None:
    columns = [
        "request_id", "started_at", "client_ip", "user_agent", "method",
        "path", "image_mime", "image_bytes", "prompt_chars", "status_code",
        "duration_ms", "response_bytes", "usage_json", "error",
    ]
    payload = [values.get(column) for column in columns]
    with sqlite3.connect(db_path()) as connection:
        connection.execute(
            f"INSERT INTO requests ({','.join(columns)}) VALUES ({','.join('?' for _ in columns)})",
            payload,
        )


def count_since(client_ip: str, started_at_from: str) -> int:
    with sqlite3.connect(db_path()) as connection:
        row = connection.execute(
            """
            SELECT COUNT(*)
            FROM requests
            WHERE client_ip = ?
              AND started_at >= ?
              AND path IN ('/receipt', '/receipt/', '/recipe', '/recipe/')
            """,
            (client_ip, started_at_from),
        ).fetchone()
    return int(row[0] if row else 0)


def request_context() -> tuple[str, str, float]:
    return str(uuid.uuid4()), time.strftime("%Y-%m-%dT%H:%M:%SZ", time.gmtime()), time.monotonic()


def usage_json(usage: dict) -> str:
    return json.dumps(usage, ensure_ascii=True, separators=(",", ":"))