# -*- coding: utf-8 -*-
"""M5 Web 编辑器的 SQLite 存储层。

表 events：group(PK)/title/theme/status/ir_json/updated_at/updated_by/notes。
末次写入生效（设计接受），不做锁。
表 sessions：token(PK)/user/expires_at——登录会话（cookie 只存随机 token，不存口令）。
"""
import json
import os
import sqlite3

# DB 路径：容器内用 STORY_DB_PATH 指向挂载卷（持久化）；本地默认同目录。
_DB_PATH = os.environ.get("STORY_DB_PATH") or \
    os.path.join(os.path.dirname(os.path.abspath(__file__)), "story_events.db")

STATUSES = ("pending", "confirmed", "discarded")


def _conn(path=None):
    c = sqlite3.connect(path or _DB_PATH)
    c.row_factory = sqlite3.Row
    return c


def init_db(path=None):
    d = os.path.dirname(path or _DB_PATH)
    if d and not os.path.isdir(d):
        os.makedirs(d, exist_ok=True)
    with _conn(path) as c:
        c.execute(
            """CREATE TABLE IF NOT EXISTS events (
                "group"    TEXT PRIMARY KEY,
                title      TEXT,
                theme      TEXT,
                scene      TEXT DEFAULT '',
                status     TEXT NOT NULL DEFAULT 'pending',
                ir_json    TEXT NOT NULL,
                updated_at TEXT,
                updated_by TEXT,
                notes      TEXT
            )"""
        )
        # 旧库迁移：补 scene 列（海选审核按场景分组的归类维度，镜像自 ir.scene）。
        try:
            c.execute("ALTER TABLE events ADD COLUMN scene TEXT DEFAULT ''")
        except sqlite3.OperationalError:
            pass  # 已存在
        c.execute(
            """CREATE TABLE IF NOT EXISTS sessions (
                token      TEXT PRIMARY KEY,
                user       TEXT NOT NULL,
                expires_at REAL NOT NULL
            )"""
        )


# ---------- 会话 ----------
def create_session(token, user, expires_at, path=None):
    with _conn(path) as c:
        c.execute("INSERT OR REPLACE INTO sessions (token, user, expires_at) "
                  "VALUES (?,?,?)", (token, user, expires_at))


def get_session_user(token, now, path=None):
    """token 有效返回用户名；过期则顺手删除并返回 None。"""
    with _conn(path) as c:
        r = c.execute("SELECT user, expires_at FROM sessions WHERE token=?",
                      (token,)).fetchone()
        if not r:
            return None
        if r["expires_at"] < now:
            c.execute("DELETE FROM sessions WHERE token=?", (token,))
            return None
        return r["user"]


def delete_session(token, path=None):
    with _conn(path) as c:
        c.execute("DELETE FROM sessions WHERE token=?", (token,))


def purge_sessions(now, path=None):
    with _conn(path) as c:
        c.execute("DELETE FROM sessions WHERE expires_at < ?", (now,))


def list_events(status=None, path=None):
    """列表（不含 ir_json，轻量）。"""
    sql = ('SELECT "group", title, theme, scene, status, updated_at, updated_by, notes '
           "FROM events")
    args = []
    if status and status != "all":
        sql += " WHERE status = ?"
        args.append(status)
    sql += " ORDER BY updated_at DESC"
    with _conn(path) as c:
        return [dict(r) for r in c.execute(sql, args).fetchall()]


def get_event(group, path=None):
    with _conn(path) as c:
        r = c.execute('SELECT * FROM events WHERE "group" = ?', (group,)).fetchone()
        if not r:
            return None
        d = dict(r)
        d["ir"] = json.loads(d.pop("ir_json"))
        return d


def upsert_event(ir, by, now, notes=None, keep_status=True, path=None):
    """插入或更新。已存在时默认保留状态（仅刷新 ir/title/theme/元信息）。"""
    group = ir["id"]
    title = ir.get("title", "")
    theme = ir.get("theme", "")
    scene = ir.get("scene", "") or ""   # 海选审核分组维度，镜像自 ir.scene
    ir_str = json.dumps(ir, ensure_ascii=False)
    with _conn(path) as c:
        exists = c.execute('SELECT status FROM events WHERE "group" = ?',
                           (group,)).fetchone()
        if exists:
            c.execute(
                'UPDATE events SET title=?, theme=?, scene=?, ir_json=?, updated_at=?, '
                'updated_by=?, notes=COALESCE(?, notes) WHERE "group"=?',
                (title, theme, scene, ir_str, now, by, notes, group),
            )
        else:
            c.execute(
                'INSERT INTO events ("group", title, theme, scene, status, ir_json, '
                "updated_at, updated_by, notes) VALUES (?,?,?,?,?,?,?,?,?)",
                (group, title, theme, scene, "pending", ir_str, now, by, notes or ""),
            )
    return group


def set_status(group, status, by, now, path=None):
    if status not in STATUSES:
        raise ValueError("非法状态: %r" % status)
    with _conn(path) as c:
        cur = c.execute(
            'UPDATE events SET status=?, updated_at=?, updated_by=? WHERE "group"=?',
            (status, now, by, group),
        )
        return cur.rowcount > 0


def confirmed_events(path=None):
    """所有 confirmed 事件的 (group, ir) 列表，供导出编译。"""
    with _conn(path) as c:
        rows = c.execute(
            'SELECT "group", ir_json FROM events WHERE status=? ORDER BY "group"',
            ("confirmed",),
        ).fetchall()
    return [(r["group"], json.loads(r["ir_json"])) for r in rows]