-- 创建settings配置表
CREATE TABLE IF NOT EXISTS settings (
    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    key VARCHAR(255) NOT NULL UNIQUE,
    value TEXT,
    value_type VARCHAR(50) NOT NULL DEFAULT 'string', -- string, number, boolean, json
    description TEXT,
    category VARCHAR(100) DEFAULT 'general',
    is_encrypted BOOLEAN DEFAULT FALSE,
    is_system BOOLEAN DEFAULT FALSE, -- 系统配置，不允许删除
    is_editable BOOLEAN DEFAULT TRUE, -- 是否允许编辑
    created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
    updated_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
    created_by UUID,
    updated_by UUID
);

-- 添加字段注释
COMMENT ON COLUMN settings.id IS '配置项唯一标识符';
COMMENT ON COLUMN settings.key IS '配置键名，全局唯一';
COMMENT ON COLUMN settings.value IS '配置值';
COMMENT ON COLUMN settings.value_type IS '值类型：string, number, boolean, json';
COMMENT ON COLUMN settings.description IS '配置项描述';
COMMENT ON COLUMN settings.category IS '配置分类，便于分组管理';
COMMENT ON COLUMN settings.is_encrypted IS '是否为加密值';
COMMENT ON COLUMN settings.is_system IS '是否为系统配置';
COMMENT ON COLUMN settings.is_editable IS '是否允许编辑';
COMMENT ON COLUMN settings.created_by IS '创建者ID';
COMMENT ON COLUMN settings.updated_by IS '更新者ID';

-- 创建索引
CREATE INDEX IF NOT EXISTS idx_settings_key ON settings(key);
CREATE INDEX IF NOT EXISTS idx_settings_category ON settings(category);
CREATE INDEX IF NOT EXISTS idx_settings_is_system ON settings(is_system);
CREATE INDEX IF NOT EXISTS idx_settings_created_at ON settings(created_at);

-- 创建复合索引
CREATE INDEX IF NOT EXISTS idx_settings_category_key ON settings(category, key);

-- 为表创建更新时间触发器
CREATE TRIGGER update_settings_updated_at 
    BEFORE UPDATE ON settings 
    FOR EACH ROW 
    EXECUTE FUNCTION update_updated_at_column();

-- 插入一些默认配置
INSERT INTO settings (key, value, value_type, description, category, is_system) VALUES
('app.name', 'MMAP System', 'string', '应用名称', 'app', true),
('app.version', '1.0.0', 'string', '应用版本', 'app', true),
('app.debug', 'false', 'boolean', '调试模式', 'app', true),
('app.timezone', 'UTC', 'string', '系统时区', 'app', true),
('database.max_connections', '10', 'number', '数据库最大连接数', 'database', true),
('database.connection_timeout', '30', 'number', '数据库连接超时时间(秒)', 'database', true),
('kafka.max_retries', '3', 'number', 'Kafka最大重试次数', 'kafka', true),
('kafka.retry_delay', '1000', 'number', 'Kafka重试延迟(毫秒)', 'kafka', true),
('security.session_timeout', '3600', 'number', '会话超时时间(秒)', 'security', true),
('security.max_login_attempts', '5', 'number', '最大登录尝试次数', 'security', true),
('logging.level', 'info', 'string', '日志级别', 'logging', true),
('logging.max_files', '10', 'number', '最大日志文件数', 'logging', true),
('cache.ttl', '300', 'number', '缓存生存时间(秒)', 'cache', true),
('cache.max_size', '1000', 'number', '缓存最大条目数', 'cache', true)
ON CONFLICT (key) DO NOTHING;

-- 创建配置历史表（可选，用于审计）
CREATE TABLE IF NOT EXISTS settings_history (
    id UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
    setting_id UUID NOT NULL REFERENCES settings(id) ON DELETE CASCADE,
    old_value TEXT,
    new_value TEXT,
    changed_by UUID,
    change_reason TEXT,
    created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP
);

-- 为历史表创建索引
CREATE INDEX IF NOT EXISTS idx_settings_history_setting_id ON settings_history(setting_id);
CREATE INDEX IF NOT EXISTS idx_settings_history_created_at ON settings_history(created_at);

-- 创建配置变更触发器
CREATE OR REPLACE FUNCTION log_setting_change()
RETURNS TRIGGER AS $$
BEGIN
    IF OLD.value IS DISTINCT FROM NEW.value THEN
        INSERT INTO settings_history (setting_id, old_value, new_value, changed_by)
        VALUES (NEW.id, OLD.value, NEW.value, NEW.updated_by);
    END IF;
    RETURN NEW;
END;
$$ language 'plpgsql';

-- 为settings表创建变更日志触发器
CREATE TRIGGER log_settings_changes
    AFTER UPDATE ON settings
    FOR EACH ROW
    EXECUTE FUNCTION log_setting_change();