-- HBR 爬蟲系統資料表結構
-- 資料庫: HBR_scraper
-- 建立日期: 2024-12-22

-- 1. 文章主表 (articles)
CREATE TABLE IF NOT EXISTS `articles` (
    `id` BIGINT UNSIGNED NOT NULL AUTO_INCREMENT COMMENT '文章唯一識別碼',
    `title` VARCHAR(500) NOT NULL COMMENT '文章標題',
    `url` VARCHAR(1000) NOT NULL COMMENT '文章網址',
    `author` VARCHAR(200) DEFAULT NULL COMMENT '作者名稱',
    `publish_date` DATETIME DEFAULT NULL COMMENT '發布日期',
    `summary` TEXT DEFAULT NULL COMMENT '文章摘要',
    `is_paywalled` TINYINT(1) NOT NULL DEFAULT 0 COMMENT '是否為付費文章 (1=是, 0=否)',
    `category` VARCHAR(100) DEFAULT NULL COMMENT '文章分類',
    `tags` VARCHAR(500) DEFAULT NULL COMMENT '標籤（逗號分隔字串，非正規化設計）',
    `content` TEXT DEFAULT NULL COMMENT '文章內容（僅非付費文章）',
    `language` VARCHAR(10) DEFAULT 'zh-TW' COMMENT '語言代碼（zh-TW, en, ko）',
    `crawl_count` INT DEFAULT 1 COMMENT '爬取次數（用於追蹤歷史記錄）',
    `created_at` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '資料建立時間',
    `updated_at` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT '資料更新時間',
    `crawled_at` DATETIME DEFAULT NULL COMMENT '爬取時間',
    PRIMARY KEY (`id`),
    UNIQUE KEY `idx_url` (`url`(255)),
    KEY `idx_publish_date` (`publish_date`),
    KEY `idx_category` (`category`),
    KEY `idx_is_paywalled` (`is_paywalled`),
    KEY `idx_crawled_at` (`crawled_at`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci COMMENT='文章主表';

-- 2. 標籤表 (tags)
CREATE TABLE IF NOT EXISTS `tags` (
    `id` BIGINT UNSIGNED NOT NULL AUTO_INCREMENT COMMENT '標籤唯一識別碼',
    `name` VARCHAR(100) NOT NULL COMMENT '標籤名稱',
    `created_at` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '建立時間',
    PRIMARY KEY (`id`),
    UNIQUE KEY `idx_name` (`name`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci COMMENT='標籤表';

-- 3. 文章標籤關聯表 (article_tags)
CREATE TABLE IF NOT EXISTS `article_tags` (
    `id` BIGINT UNSIGNED NOT NULL AUTO_INCREMENT COMMENT '關聯唯一識別碼',
    `article_id` BIGINT UNSIGNED NOT NULL COMMENT '文章 ID',
    `tag_id` BIGINT UNSIGNED NOT NULL COMMENT '標籤 ID',
    `created_at` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '建立時間',
    PRIMARY KEY (`id`),
    UNIQUE KEY `idx_article_tag` (`article_id`, `tag_id`),
    KEY `idx_article_id` (`article_id`),
    KEY `idx_tag_id` (`tag_id`),
    CONSTRAINT `fk_article_tags_article` FOREIGN KEY (`article_id`) 
        REFERENCES `articles` (`id`) ON DELETE CASCADE ON UPDATE CASCADE,
    CONSTRAINT `fk_article_tags_tag` FOREIGN KEY (`tag_id`) 
        REFERENCES `tags` (`id`) ON DELETE CASCADE ON UPDATE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci COMMENT='文章標籤關聯表';