-- ============================================
-- 数据模型统一重构回滚脚本
-- 用于撤销data_model_unification.sql的所有变更
-- 创建时间：2025-01-15
-- 注意：执行前请确保有完整的数据备份！
-- ============================================

-- 开始事务
BEGIN;

-- 设置错误处理
\set ON_ERROR_STOP on

-- ============================================
-- 第一阶段：创建映射表（用于回滚）
-- ============================================

-- 创建回滚映射表
CREATE TABLE IF NOT EXISTS rollback_vehicle_mapping (
    vehicle_id BIGINT PRIMARY KEY,
    license_plate VARCHAR(50),
    old_vehicle_id VARCHAR(50)
);

-- 填充映射表数据
INSERT INTO rollback_vehicle_mapping (vehicle_id, license_plate, old_vehicle_id)
SELECT 
    vi.vehicle_id,
    vi.license_plate,
    vi.license_plate as old_vehicle_id
FROM sys_vehicle_info vi
ON CONFLICT (vehicle_id) DO NOTHING;

-- ============================================
-- 第二阶段：恢复CollisionAvoidanceSystem表结构
-- ============================================

-- 1. 恢复vehicle_locations表
-- 添加临时字段
ALTER TABLE vehicle_locations ADD COLUMN IF NOT EXISTS vehicle_id_old VARCHAR(50);

-- 填充旧字段数据
UPDATE vehicle_locations vl
SET vehicle_id_old = rvm.old_vehicle_id
FROM rollback_vehicle_mapping rvm
WHERE vl.vehicle_id = rvm.vehicle_id;

-- 删除新字段，重命名旧字段
ALTER TABLE vehicle_locations DROP COLUMN IF EXISTS vehicle_id;
ALTER TABLE vehicle_locations DROP COLUMN IF EXISTS license_plate;
ALTER TABLE vehicle_locations RENAME COLUMN vehicle_id_old TO vehicle_id;

-- 2. 恢复vehicle_trajectories表
-- 添加临时字段
ALTER TABLE vehicle_trajectories ADD COLUMN IF NOT EXISTS vehicle_id_old VARCHAR(50);

-- 填充旧字段数据
UPDATE vehicle_trajectories vt
SET vehicle_id_old = rvm.old_vehicle_id
FROM rollback_vehicle_mapping rvm
WHERE vt.vehicle_id = rvm.vehicle_id;

-- 删除新字段，重命名旧字段
ALTER TABLE vehicle_trajectories DROP COLUMN IF EXISTS vehicle_id;
ALTER TABLE vehicle_trajectories DROP COLUMN IF EXISTS license_plate;
ALTER TABLE vehicle_trajectories RENAME COLUMN vehicle_id_old TO vehicle_id;

-- 3. 恢复vehicle_commands表
-- 添加临时字段
ALTER TABLE vehicle_commands ADD COLUMN IF NOT EXISTS vehicle_id_old VARCHAR(50);

-- 填充旧字段数据
UPDATE vehicle_commands vc
SET vehicle_id_old = rvm.old_vehicle_id
FROM rollback_vehicle_mapping rvm
WHERE vc.vehicle_id = rvm.vehicle_id;

-- 删除新字段，重命名旧字段
ALTER TABLE vehicle_commands DROP COLUMN IF EXISTS vehicle_id;
ALTER TABLE vehicle_commands DROP COLUMN IF EXISTS license_plate;
ALTER TABLE vehicle_commands RENAME COLUMN vehicle_id_old TO vehicle_id;

-- 4. 恢复rule_violation_events表
-- 添加临时字段
ALTER TABLE rule_violation_events ADD COLUMN IF NOT EXISTS subject_id_old VARCHAR(50);

-- 填充旧字段数据
UPDATE rule_violation_events rve
SET subject_id_old = CASE 
    WHEN rve.subject_type = 'VEHICLE' THEN rvm.old_vehicle_id
    ELSE rve.subject_id
END
FROM rollback_vehicle_mapping rvm
WHERE rve.subject_type = 'VEHICLE' 
AND rve.subject_id = rvm.vehicle_id::VARCHAR;

-- 删除新字段，重命名旧字段
ALTER TABLE rule_violation_events DROP COLUMN IF EXISTS subject_id;
ALTER TABLE rule_violation_events DROP COLUMN IF EXISTS license_plate;
ALTER TABLE rule_violation_events DROP COLUMN IF EXISTS vehicle_id_new;
ALTER TABLE rule_violation_events RENAME COLUMN subject_id_old TO subject_id;

-- ============================================
-- 第三阶段：恢复QAUP-Management表结构
-- ============================================

-- 1. 恢复sys_vehicle_info表字段名
ALTER TABLE sys_vehicle_info RENAME COLUMN license_plate TO license_plate_number;

-- 2. 删除自动创建的车辆记录
DELETE FROM sys_vehicle_info 
WHERE create_by = 'system' 
AND remark = '数据模型统一时自动创建';

-- ============================================
-- 第四阶段：恢复索引
-- ============================================

-- 1. 恢复vehicle_locations表索引
DROP INDEX IF EXISTS idx_vehicle_locations_vehicle_id;
DROP INDEX IF EXISTS idx_vehicle_locations_license_plate;
CREATE INDEX idx_vehicle_locations_vehicle_id ON vehicle_locations(vehicle_id);

-- 2. 恢复vehicle_trajectories表索引
DROP INDEX IF EXISTS idx_vehicle_trajectories_vehicle_id;
DROP INDEX IF EXISTS idx_vehicle_trajectories_license_plate;
CREATE INDEX idx_vehicle_trajectories_vehicle_id ON vehicle_trajectories(vehicle_id);

-- 3. 恢复vehicle_commands表索引
DROP INDEX IF EXISTS idx_vehicle_commands_vehicle_id;
DROP INDEX IF EXISTS idx_vehicle_commands_license_plate;
CREATE INDEX idx_vehicle_commands_vehicle_id ON vehicle_commands(vehicle_id);

-- 4. 恢复rule_violation_events表索引
DROP INDEX IF EXISTS idx_rule_violations_license_plate;

-- ============================================
-- 第五阶段：删除外键约束（如果存在）
-- ============================================

-- 删除外键约束
ALTER TABLE vehicle_locations DROP CONSTRAINT IF EXISTS fk_vehicle_locations_vehicle_id;
ALTER TABLE vehicle_trajectories DROP CONSTRAINT IF EXISTS fk_vehicle_trajectories_vehicle_id;
ALTER TABLE vehicle_commands DROP CONSTRAINT IF EXISTS fk_vehicle_commands_vehicle_id;

-- ============================================
-- 第六阶段：恢复业务视图
-- ============================================

-- 删除新视图
DROP VIEW IF EXISTS vehicle_complete_info;
DROP VIEW IF EXISTS vehicle_status_summary;
DROP VIEW IF EXISTS vehicle_info_with_location;
DROP VIEW IF EXISTS vehicle_trajectory_view;

-- 重新创建原始视图（基于原始字段结构）
CREATE VIEW vehicle_complete_info AS
SELECT 
    vi.vehicle_id,
    vi.license_plate_number,
    vi.vin_number,
    vi.type_id,
    vt.type_name,
    vi.brand,
    vi.owning_unit,
    vi.contact_person,
    vi.phone_number,
    vi.image_url,
    vl.location,
    vl.altitude,
    vl.heading,
    vl.speed,
    vl.timestamp as last_location_time,
    vl.data_quality,
    vi.create_time,
    vi.update_time
FROM sys_vehicle_info vi
LEFT JOIN sys_vehicle_type vt ON vi.type_id = vt.type_id
LEFT JOIN LATERAL (
    SELECT * FROM vehicle_locations 
    WHERE vehicle_id = vi.license_plate_number 
    ORDER BY timestamp DESC 
    LIMIT 1
) vl ON true;

-- 车辆状态统计视图
CREATE VIEW vehicle_status_summary AS
SELECT 
    vehicle_type,
    COUNT(*) as total_vehicles,
    COUNT(CASE WHEN timestamp > NOW() - INTERVAL '5 minutes' THEN 1 END) as active_vehicles,
    COUNT(CASE WHEN timestamp <= NOW() - INTERVAL '5 minutes' THEN 1 END) as inactive_vehicles,
    AVG(speed) as avg_speed,
    MAX(speed) as max_speed
FROM vehicle_locations vl
WHERE timestamp > NOW() - INTERVAL '24 hours'
GROUP BY vehicle_type;

-- 车辆信息与位置关联视图
CREATE VIEW vehicle_info_with_location AS
SELECT 
    vi.vehicle_id as sys_vehicle_id,
    vi.license_plate_number as vehicle_plate,
    vi.brand,
    vi.owning_unit,
    vt.type_name as vehicle_type_name,
    vl.vehicle_type as location_vehicle_type,
    vl.location,
    ST_X(vl.location) as longitude,
    ST_Y(vl.location) as latitude,
    vl.altitude,
    vl.heading,
    vl.speed,
    vl.timestamp as last_update_time,
    CASE 
        WHEN vl.timestamp > NOW() - INTERVAL '5 minutes' THEN 'ACTIVE'
        WHEN vl.timestamp > NOW() - INTERVAL '30 minutes' THEN 'INACTIVE'
        ELSE 'OFFLINE'
    END as status
FROM sys_vehicle_info vi
LEFT JOIN sys_vehicle_type vt ON vi.type_id = vt.type_id
LEFT JOIN LATERAL (
    SELECT * FROM vehicle_locations 
    WHERE vehicle_id = vi.license_plate_number 
    ORDER BY timestamp DESC 
    LIMIT 1
) vl ON true;

-- 车辆轨迹查询视图
CREATE VIEW vehicle_trajectory_view AS
SELECT 
    vi.vehicle_id as sys_vehicle_id,
    vi.license_plate_number as vehicle_plate,
    vi.brand,
    vt.trajectory_date,
    vt.trajectory_line,
    vt.total_distance,
    vt.max_speed,
    vt.avg_speed,
    vt.duration_seconds,
    vt.start_time,
    vt.end_time
FROM sys_vehicle_info vi
INNER JOIN vehicle_trajectories vt ON vt.vehicle_id = vi.license_plate_number
LEFT JOIN sys_vehicle_type vtype ON vi.type_id = vtype.type_id;

-- ============================================
-- 第七阶段：恢复字段注释
-- ============================================

-- 恢复sys_vehicle_info表字段注释
COMMENT ON COLUMN sys_vehicle_info.license_plate_number IS '车牌号';

-- 恢复vehicle_locations表字段注释
COMMENT ON COLUMN vehicle_locations.vehicle_id IS '车辆标识符（车牌号、航班号等）';

-- 恢复vehicle_trajectories表字段注释
COMMENT ON COLUMN vehicle_trajectories.vehicle_id IS '车辆标识符（车牌号、航班号等）';

-- 恢复vehicle_commands表字段注释
COMMENT ON COLUMN vehicle_commands.vehicle_id IS '车辆ID';

-- ============================================
-- 第八阶段：清理临时数据
-- ============================================

-- 删除回滚映射表
DROP TABLE IF EXISTS rollback_vehicle_mapping;

-- ============================================
-- 最终验证
-- ============================================

DO $$
DECLARE
    qaup_count INTEGER;
    locations_count INTEGER;
    trajectories_count INTEGER;
    commands_count INTEGER;
    violations_count INTEGER;
BEGIN
    -- 统计各表记录数
    SELECT COUNT(*) INTO qaup_count FROM sys_vehicle_info;
    SELECT COUNT(*) INTO locations_count FROM vehicle_locations;
    SELECT COUNT(*) INTO trajectories_count FROM vehicle_trajectories;
    SELECT COUNT(*) INTO commands_count FROM vehicle_commands;
    SELECT COUNT(*) INTO violations_count FROM rule_violation_events WHERE subject_type = 'VEHICLE';
    
    -- 输出统计信息
    RAISE NOTICE '==============================================';
    RAISE NOTICE '数据模型统一重构回滚完成！';
    RAISE NOTICE '==============================================';
    RAISE NOTICE '车辆信息记录: %', qaup_count;
    RAISE NOTICE '位置记录: %', locations_count;
    RAISE NOTICE '轨迹记录: %', trajectories_count;
    RAISE NOTICE '指令记录: %', commands_count;
    RAISE NOTICE '违规事件记录: %', violations_count;
    RAISE NOTICE '==============================================';
    RAISE NOTICE '已恢复到原始数据模型：';
    RAISE NOTICE '1. vehicle_id恢复为字符串类型（车牌号）';
    RAISE NOTICE '2. license_plate_number恢复为原始字段名';
    RAISE NOTICE '3. 删除了所有新增字段';
    RAISE NOTICE '4. 恢复了原始业务视图';
    RAISE NOTICE '5. 恢复了原始索引结构';
    RAISE NOTICE '==============================================';
END $$;

-- 提交事务
COMMIT;

-- 显示完成消息
\echo '数据模型统一重构回滚脚本执行完成！'
\echo '已恢复到原始数据模型状态。'