-- 音乐总分类 / 子分类 + 曲目多对多。种子：首页 + 分类1/2/3；按 demo 曲名分配到子分类。

CREATE TABLE IF NOT EXISTS t_music_categories (
    id          BIGINT PRIMARY KEY AUTO_INCREMENT COMMENT '分类自增 id',
    parent_id   BIGINT NULL COMMENT 'NULL=总分类；非空=所属总分类 id',
    name        VARCHAR(128) NOT NULL DEFAULT '' COMMENT '分类名称（后台可改）',
    sort_order  INT NOT NULL DEFAULT 0 COMMENT '越小越靠前',
    enabled     TINYINT(1) NOT NULL DEFAULT 1 COMMENT '1=启用',
    created_at  DATETIME(3) NOT NULL COMMENT '创建时间',
    updated_at  DATETIME(3) NOT NULL COMMENT '更新时间',
    KEY idx_music_cat_parent (parent_id, enabled, sort_order, id),
    KEY idx_music_cat_name (name)
) COMMENT='音乐总分类与子分类';

CREATE TABLE IF NOT EXISTS t_music_category_tracks (
    category_id BIGINT NOT NULL COMMENT '分类 id',
    track_id    BIGINT NOT NULL COMMENT '曲目 id',
    created_at  DATETIME(3) NOT NULL COMMENT '绑定时间',
    PRIMARY KEY (category_id, track_id),
    KEY idx_mct_track (track_id)
) COMMENT='曲目与分类多对多（同一曲可属多个分类）';

INSERT INTO t_music_categories (parent_id, name, sort_order, enabled, created_at, updated_at)
SELECT NULL, '首页', 0, 1, CURRENT_TIMESTAMP(3), CURRENT_TIMESTAMP(3)
FROM DUAL
WHERE NOT EXISTS (
    SELECT 1 FROM t_music_categories WHERE parent_id IS NULL AND name = '首页'
);

INSERT INTO t_music_categories (parent_id, name, sort_order, enabled, created_at, updated_at)
SELECT p.id, '分类1', 1, 1, CURRENT_TIMESTAMP(3), CURRENT_TIMESTAMP(3)
FROM t_music_categories p
WHERE p.parent_id IS NULL AND p.name = '首页'
  AND NOT EXISTS (
    SELECT 1 FROM t_music_categories c WHERE c.parent_id = p.id AND c.name = '分类1'
  );

INSERT INTO t_music_categories (parent_id, name, sort_order, enabled, created_at, updated_at)
SELECT p.id, '分类2', 2, 1, CURRENT_TIMESTAMP(3), CURRENT_TIMESTAMP(3)
FROM t_music_categories p
WHERE p.parent_id IS NULL AND p.name = '首页'
  AND NOT EXISTS (
    SELECT 1 FROM t_music_categories c WHERE c.parent_id = p.id AND c.name = '分类2'
  );

INSERT INTO t_music_categories (parent_id, name, sort_order, enabled, created_at, updated_at)
SELECT p.id, '分类3', 3, 1, CURRENT_TIMESTAMP(3), CURRENT_TIMESTAMP(3)
FROM t_music_categories p
WHERE p.parent_id IS NULL AND p.name = '首页'
  AND NOT EXISTS (
    SELECT 1 FROM t_music_categories c WHERE c.parent_id = p.id AND c.name = '分类3'
  );

INSERT INTO t_music_category_tracks (category_id, track_id, created_at)
SELECT c.id, t.id, CURRENT_TIMESTAMP(3)
FROM t_music_categories c
JOIN t_music_tracks t ON t.title IN ('晨光微风', '城市夜行', '雨巷漫步', '山间回响')
WHERE c.name = '分类1'
  AND c.parent_id IS NOT NULL
  AND NOT EXISTS (
    SELECT 1 FROM t_music_category_tracks x WHERE x.category_id = c.id AND x.track_id = t.id
  );

INSERT INTO t_music_category_tracks (category_id, track_id, created_at)
SELECT c.id, t.id, CURRENT_TIMESTAMP(3)
FROM t_music_categories c
JOIN t_music_tracks t ON t.title IN ('海边日落', '咖啡馆时光', '极光之夜', '纸飞机')
WHERE c.name = '分类2'
  AND c.parent_id IS NOT NULL
  AND NOT EXISTS (
    SELECT 1 FROM t_music_category_tracks x WHERE x.category_id = c.id AND x.track_id = t.id
  );

INSERT INTO t_music_category_tracks (category_id, track_id, created_at)
SELECT c.id, t.id, CURRENT_TIMESTAMP(3)
FROM t_music_categories c
JOIN t_music_tracks t ON t.title IN ('极光之夜', '星河入梦', '旅途序曲', '晨光微风')
WHERE c.name = '分类3'
  AND c.parent_id IS NOT NULL
  AND NOT EXISTS (
    SELECT 1 FROM t_music_category_tracks x WHERE x.category_id = c.id AND x.track_id = t.id
  );