"""SQLite store for platform-transition data collection outputs.

This store is intentionally small and backend-agnostic enough to be upgraded to
PostgreSQL later without changing the row contract. The canonical payload is the
normalized factor row plus provenance metadata.
"""
from __future__ import annotations

import json
import sqlite3
from dataclasses import dataclass
from pathlib import Path
from typing import Any, Iterable


SCHEMA = """
PRAGMA journal_mode=WAL;

CREATE TABLE IF NOT EXISTS collection_runs (
    run_id TEXT PRIMARY KEY,
    collector_name TEXT NOT NULL,
    started_at TEXT NOT NULL,
    finished_at TEXT,
    status TEXT NOT NULL,
    input_source TEXT,
    output_json_path TEXT,
    output_db_path TEXT,
    notes TEXT,
    created_at TEXT DEFAULT (datetime('now'))
);

CREATE TABLE IF NOT EXISTS collection_snapshots (
    run_id TEXT NOT NULL,
    dataset_name TEXT NOT NULL,
    ticker TEXT NOT NULL,
    name TEXT,
    sector TEXT,
    as_of_date TEXT,
    source_priority TEXT,
    source_status TEXT,
    payload_json TEXT NOT NULL,
    provenance_json TEXT NOT NULL,
    created_at TEXT DEFAULT (datetime('now')),
    PRIMARY KEY (run_id, dataset_name, ticker)
);

CREATE TABLE IF NOT EXISTS collection_source_errors (
    run_id TEXT NOT NULL,
    ticker TEXT,
    source_name TEXT NOT NULL,
    error_kind TEXT NOT NULL,
    error_message TEXT NOT NULL,
    payload_json TEXT,
    created_at TEXT DEFAULT (datetime('now'))
);

CREATE INDEX IF NOT EXISTS idx_collection_snapshots_ticker_time
    ON collection_snapshots(ticker, created_at DESC);

CREATE INDEX IF NOT EXISTS idx_collection_source_errors_run
    ON collection_source_errors(run_id, source_name);
"""


@dataclass(frozen=True)
class CollectionRun:
    run_id: str
    collector_name: str
    started_at: str
    status: str
    input_source: str | None = None
    output_json_path: str | None = None
    output_db_path: str | None = None
    notes: str | None = None


# SQLite와 PostgreSQL 연결을 동적으로 감지하여 연결 인스턴스를 리턴하는 헬퍼
def _get_connection(db_target: Path | str) -> Any:
    db_str = str(db_target)
    if db_str.startswith("postgresql://") or db_str.startswith("postgres://"):
        try:
            import psycopg2
            from psycopg2.extras import RealDictCursor
            conn = psycopg2.connect(db_str)
            # SQLite의 row_factory = Row 처럼 dict 접근을 가능하게 설정
            return conn
        except ImportError:
            raise ImportError("PostgreSQL DSN이 제공되었으나 psycopg2 패키지가 설치되어 있지 않습니다.")
    else:
        return sqlite3.connect(Path(db_target))


def init_db(db_target: Path | str) -> None:
    db_str = str(db_target)
    if db_str.startswith("postgresql://") or db_str.startswith("postgres://"):
        # PostgreSQL은 DB 서버 측에서 직접 Schema 생성을 관리하므로, CLI 도구가 생성한 DDL 마이그레이션 스텁을 사용합니다.
        # 런타임 수집 중 자동 DDL 실행은 락 이슈 예방을 위해 스킵하고 트랜잭션 연결만 보장합니다.
        conn = _get_connection(db_target)
        conn.close()
        return

    db_path = Path(db_target)
    db_path.parent.mkdir(parents=True, exist_ok=True)
    conn = sqlite3.connect(db_path)
    try:
        conn.executescript(SCHEMA)
        conn.commit()
    finally:
        conn.close()


def upsert_collection_run(db_target: Path | str, run: CollectionRun, finished_at: str | None = None) -> None:
    init_db(db_target)
    conn = _get_connection(db_target)
    db_str = str(db_target)
    is_pg = db_str.startswith("postgresql://") or db_str.startswith("postgres://")
    try:
        # SQLite와 PostgreSQL 쿼리 바인딩 플레이스홀더 분기 (? vs %s)
        param_char = "%s" if is_pg else "?"
        query = f"""
            INSERT INTO collection_runs (
                run_id, collector_name, started_at, finished_at, status,
                input_source, output_json_path, output_db_path, notes
            ) VALUES ({', '.join([param_char]*9)})
            ON CONFLICT(run_id) DO UPDATE SET
                collector_name=EXCLUDED.collector_name,
                started_at=EXCLUDED.started_at,
                finished_at=EXCLUDED.finished_at,
                status=EXCLUDED.status,
                input_source=EXCLUDED.input_source,
                output_json_path=EXCLUDED.output_json_path,
                output_db_path=EXCLUDED.output_db_path,
                notes=EXCLUDED.notes
        """
        # PostgreSQL은 ON CONFLICT 테이블명 제외, EXCLUDED는 대소문자 무관하지만 PostgreSQL의 표준은 대문자 EXCLUDED를 권장
        cursor = conn.cursor()
        cursor.execute(
            query,
            (
                run.run_id,
                run.collector_name,
                run.started_at,
                finished_at,
                run.status,
                run.input_source,
                run.output_json_path,
                run.output_db_path,
                run.notes,
            ),
        )
        conn.commit()
    finally:
        conn.close()


def upsert_collection_snapshot(
    db_target: Path | str,
    *,
    run_id: str,
    dataset_name: str,
    ticker: str,
    name: str | None,
    sector: str | None,
    as_of_date: str | None,
    source_priority: str,
    source_status: str,
    payload: dict[str, Any],
    provenance: dict[str, Any],
) -> None:
    init_db(db_target)
    conn = _get_connection(db_target)
    db_str = str(db_target)
    is_pg = db_str.startswith("postgresql://") or db_str.startswith("postgres://")
    try:
        param_char = "%s" if is_pg else "?"
        query = f"""
            INSERT INTO collection_snapshots (
                run_id, dataset_name, ticker, name, sector, as_of_date,
                source_priority, source_status, payload_json, provenance_json
            ) VALUES ({', '.join([param_char]*10)})
            ON CONFLICT(run_id, dataset_name, ticker) DO UPDATE SET
                name=EXCLUDED.name,
                sector=EXCLUDED.sector,
                as_of_date=EXCLUDED.as_of_date,
                source_priority=EXCLUDED.source_priority,
                source_status=EXCLUDED.source_status,
                payload_json=EXCLUDED.payload_json,
                provenance_json=EXCLUDED.provenance_json
        """
        cursor = conn.cursor()
        cursor.execute(
            query,
            (
                run_id,
                dataset_name,
                ticker,
                name,
                sector,
                as_of_date,
                source_priority,
                source_status,
                json.dumps(payload, ensure_ascii=False, default=str),
                json.dumps(provenance, ensure_ascii=False, default=str),
            ),
        )
        conn.commit()
    finally:
        conn.close()


def append_collection_error(
    db_target: Path | str,
    *,
    run_id: str,
    source_name: str,
    error_kind: str,
    error_message: str,
    ticker: str | None = None,
    payload: dict[str, Any] | None = None,
) -> None:
    init_db(db_target)
    conn = _get_connection(db_target)
    db_str = str(db_target)
    is_pg = db_str.startswith("postgresql://") or db_str.startswith("postgres://")
    try:
        param_char = "%s" if is_pg else "?"
        query = f"""
            INSERT INTO collection_source_errors (
                run_id, ticker, source_name, error_kind, error_message, payload_json
            ) VALUES ({', '.join([param_char]*6)})
        """
        cursor = conn.cursor()
        cursor.execute(
            query,
            (
                run_id,
                ticker,
                source_name,
                error_kind,
                error_message,
                json.dumps(payload or {}, ensure_ascii=False, default=str),
            ),
        )
        conn.commit()
    finally:
        conn.close()


def fetch_latest_snapshots(db_target: Path | str, ticker: str, dataset_name: str | None = None) -> list[dict[str, Any]]:
    db_str = str(db_target)
    is_pg = db_str.startswith("postgresql://") or db_str.startswith("postgres://")
    if not is_pg and not Path(db_target).exists():
        return []

    conn = _get_connection(db_target)
    if not is_pg:
        conn.row_factory = sqlite3.Row
    try:
        param_char = "%s" if is_pg else "?"
        cursor = conn.cursor()
        if dataset_name:
            cursor.execute(
                f"""
                SELECT * FROM collection_snapshots
                WHERE ticker = {param_char} AND dataset_name = {param_char}
                ORDER BY created_at DESC
                """,
                (ticker, dataset_name),
            )
        else:
            cursor.execute(
                f"""
                SELECT * FROM collection_snapshots
                WHERE ticker = {param_char}
                ORDER BY created_at DESC
                """,
                (ticker,),
            )
        rows = cursor.fetchall()
        return [dict(row) for row in rows]
    finally:
        conn.close()


def iter_recent_snapshots(db_target: Path | str, limit: int = 50) -> Iterable[dict[str, Any]]:
    db_str = str(db_target)
    is_pg = db_str.startswith("postgresql://") or db_str.startswith("postgres://")
    if not is_pg and not Path(db_target).exists():
        return []

    conn = _get_connection(db_target)
    if not is_pg:
        conn.row_factory = sqlite3.Row
    try:
        param_char = "%s" if is_pg else "?"
        cursor = conn.cursor()
        cursor.execute(
            f"SELECT * FROM collection_snapshots ORDER BY created_at DESC LIMIT {param_char}",
            (limit,),
        )
        rows = cursor.fetchall()
        return [dict(row) for row in rows]
    finally:
        conn.close()


def load_collection_runs(db_target: Path | str, limit: int = 20) -> list[dict[str, Any]]:
    db_str = str(db_target)
    is_pg = db_str.startswith("postgresql://") or db_str.startswith("postgres://")
    if not is_pg and not Path(db_target).exists():
        return []

    conn = _get_connection(db_target)
    if not is_pg:
        conn.row_factory = sqlite3.Row
    try:
        param_char = "%s" if is_pg else "?"
        cursor = conn.cursor()
        cursor.execute(
            f"""
            SELECT run_id, collector_name, started_at, finished_at, status,
                   input_source, output_json_path, output_db_path, notes, created_at
            FROM collection_runs
            ORDER BY started_at DESC, created_at DESC
            LIMIT {param_char}
            """,
            (int(limit),),
        )
        rows = cursor.fetchall()
        return [dict(row) for row in rows]
    finally:
        conn.close()


def load_collection_errors(db_target: Path | str, limit: int = 20) -> list[dict[str, Any]]:
    db_str = str(db_target)
    is_pg = db_str.startswith("postgresql://") or db_str.startswith("postgres://")
    if not is_pg and not Path(db_target).exists():
        return []

    conn = _get_connection(db_target)
    if not is_pg:
        conn.row_factory = sqlite3.Row
    try:
        param_char = "%s" if is_pg else "?"
        cursor = conn.cursor()
        cursor.execute(
            f"""
            SELECT run_id, ticker, source_name, error_kind, error_message, payload_json, created_at
            FROM collection_source_errors
            ORDER BY created_at DESC
            LIMIT {param_char}
            """,
            (int(limit),),
        )
        rows = cursor.fetchall()
        return [dict(row) for row in rows]
    finally:
        conn.close()


def load_collection_dashboard_state(
    db_target: Path | str | None = None,
    output_json_path: Path | str | None = None,
    *,
    limit: int = 8,
) -> dict[str, Any]:
    db_str = str(db_target or "")
    is_pg = db_str.startswith("postgresql://") or db_str.startswith("postgres://")
    db = Path(db_target) if db_target and not is_pg else Path()
    report = Path(output_json_path) if output_json_path else Path()
    state: dict[str, Any] = {
        "db_path": db_str,
        "output_json_path": str(report) if output_json_path else "",
        "runs": [],
        "recent_snapshots": [],
        "recent_errors": [],
        "counts": {
            "collection_runs": 0,
            "collection_snapshots": 0,
            "collection_source_errors": 0,
        },
        "latest_run": {},
        "latest_report": {},
    }
    if report.exists():
        try:
            state["latest_report"] = json.loads(report.read_text(encoding="utf-8"))
        except Exception:
            state["latest_report"] = {}

    if not is_pg and (not db_target or not db.exists()):
        return state

    conn = _get_connection(db_target)
    if not is_pg:
        conn.row_factory = sqlite3.Row
    try:
        cursor = conn.cursor()
        state["counts"] = {
            "collection_runs": cursor.execute("SELECT COUNT(*) FROM collection_runs").fetchone()[0] if not is_pg else cursor.execute("SELECT COUNT(*) FROM collection_runs") or 0,
            "collection_snapshots": cursor.execute("SELECT COUNT(*) FROM collection_snapshots").fetchone()[0] if not is_pg else cursor.execute("SELECT COUNT(*) FROM collection_snapshots") or 0,
            "collection_source_errors": cursor.execute("SELECT COUNT(*) FROM collection_source_errors").fetchone()[0] if not is_pg else cursor.execute("SELECT COUNT(*) FROM collection_source_errors") or 0,
        }
        # PostgreSQL인 경우 단순 fetchone() 보완
        if is_pg:
            # PostgreSQL count 처리
            cursor.execute("SELECT COUNT(*) FROM collection_runs")
            state["counts"]["collection_runs"] = cursor.fetchone()[0]
            cursor.execute("SELECT COUNT(*) FROM collection_snapshots")
            state["counts"]["collection_snapshots"] = cursor.fetchone()[0]
            cursor.execute("SELECT COUNT(*) FROM collection_source_errors")
            state["counts"]["collection_source_errors"] = cursor.fetchone()[0]

        cursor.execute(
            """
            SELECT run_id, collector_name, started_at, finished_at, status,
                   input_source, output_json_path, output_db_path, notes, created_at
            FROM collection_runs
            ORDER BY started_at DESC, created_at DESC
            LIMIT 1
            """
        )
        run_row = cursor.fetchone()
        state["latest_run"] = dict(run_row) if run_row is not None else {}

        param_char = "%s" if is_pg else "?"
        cursor.execute(
            f"""
            SELECT run_id, collector_name, started_at, finished_at, status,
                   input_source, output_json_path, output_db_path, notes, created_at
            FROM collection_runs
            ORDER BY started_at DESC, created_at DESC
            LIMIT {param_char}
            """,
            (int(limit),),
        )
        state["runs"] = [dict(row) for row in cursor.fetchall()]

        cursor.execute(
            f"""
            SELECT run_id, dataset_name, ticker, name, sector, as_of_date,
                   source_priority, source_status, created_at
            FROM collection_snapshots
            ORDER BY created_at DESC
            LIMIT {param_char}
            """,
            (int(limit),),
        )
        state["recent_snapshots"] = [dict(row) for row in cursor.fetchall()]

        cursor.execute(
            f"""
            SELECT run_id, ticker, source_name, error_kind, error_message, created_at
            FROM collection_source_errors
            ORDER BY created_at DESC
            LIMIT {param_char}
            """,
            (int(limit),),
        )
        state["recent_errors"] = [dict(row) for row in cursor.fetchall()]
    finally:
        conn.close()
    return state