package repository

import (
	"database/sql"
	"fmt"
	"os"
	"strings"
	"testing"

	"cmautobuy/admin/config"
	"cmautobuy/admin/spec"
)

// TestMySQLMigrate_真实MySQL8 只在显式提供隔离测试库时运行。
// 库名必须以 _test 结尾，防止测试清理误碰生产库。
func TestMySQLMigrate_真实MySQL8(t *testing.T) {
	if os.Getenv("CMAUTOBUY_MYSQL_TEST") != "1" {
		t.Skip("未启用真实 MySQL 8 集成测试")
	}
	cfg, err := config.LoadDatabaseFromEnv()
	if err != nil {
		t.Fatal(err)
	}
	if !strings.HasSuffix(cfg.Name, "_test") {
		t.Fatalf("拒绝清理非测试数据库 %q：库名必须以 _test 结尾", cfg.Name)
	}
	db, err := OpenMySQL(cfg)
	if err != nil {
		t.Fatal(err)
	}
	defer db.Close()

	cleanMySQLTestSchema(t, db)
	defer cleanMySQLTestSchema(t, db)
	if err := MigrateMySQL(db); err != nil {
		t.Fatalf("首次建立 MySQL schema 失败: %v", err)
	}
	if err := MigrateMySQL(db); err != nil {
		t.Fatalf("重复迁移应该无副作用: %v", err)
	}
	var version int
	if err := db.QueryRow(`SELECT MAX(version) FROM schema_migrations`).Scan(&version); err != nil {
		t.Fatal(err)
	}
	if version != mysqlSchemaVersion {
		t.Fatalf("schema 版本=%d，期望 %d", version, mysqlSchemaVersion)
	}
}

func TestMySQLMigrate_V2升级V3并转换真实主链路(t *testing.T) {
	db := openMySQLMigrationTestDB(t)
	defer db.Close()
	cleanMySQLTestSchema(t, db)
	defer cleanMySQLTestSchema(t, db)
	prepareMySQLV2(t, db)
	now := "2026-08-10T03:00:00Z"
	mustExec(t, db, `INSERT INTO shopee_products (goods_id,title,created_at,updated_at) VALUES ('REPORT-1','报表商品',?,?)`, now, now)
	mustExec(t, db, `INSERT INTO shopee_skus (sku_id,goods_id,spec_raw,created_at,updated_at) VALUES ('SKU-1','REPORT-1','黑色, M',?,?)`, now, now)
	mustExec(t, db, `INSERT INTO sku_mappings (shopee_sku_id,pdd_goods_id,pdd_option_key,pdd_options,goods_id,mapped_at) VALUES ('SKU-1','PDD-1','color=黑色&size=M','color=黑色&size=M','REPORT-1',?)`, now)
	mustExec(t, db, `INSERT INTO syb_orders (syb_id,order_no,title,shopee_goods_id,product_spec,quantity,syb_data,created_at,updated_at) VALUES
		('SYB-1','ORDER-1','报表商品','REPORT-1','  黑色,   M  ',1,'{}',?,?),
		('SYB-2','ORDER-2','骨架商品','SKELETON-1','白色,L',1,'{}',?,?),
		('SYB-3','ORDER-3','空规格','EMPTY-1',NULL,1,'{}',?,?)`, now, now, now, now, now, now)

	if err := MigrateMySQL(db); err != nil {
		t.Fatalf("v2→v3 失败: %v", err)
	}
	var key string
	if err := db.QueryRow(`SELECT spec_key FROM syb_orders WHERE syb_id='SYB-1'`).Scan(&key); err != nil || key != "黑色, M" {
		t.Fatalf("规格回填=%q err=%v", key, err)
	}
	var empty sql.NullString
	if err := db.QueryRow(`SELECT spec_key FROM syb_orders WHERE syb_id='SYB-3'`).Scan(&empty); err != nil || empty.Valid {
		t.Fatalf("空规格必须保持 NULL: %+v err=%v", empty, err)
	}
	var source string
	if err := db.QueryRow(`SELECT source FROM shopee_products WHERE goods_id='SKELETON-1'`).Scan(&source); err != nil || source != "syb" {
		t.Fatalf("骨架来源=%q err=%v", source, err)
	}
	var mappingCount int
	if err := db.QueryRow(`SELECT COUNT(*) FROM spec_mappings WHERE shopee_goods_id='REPORT-1' AND spec_key='黑色, M' AND pdd_goods_id='PDD-1'`).Scan(&mappingCount); err != nil || mappingCount != 1 {
		t.Fatalf("旧映射转换数量=%d err=%v", mappingCount, err)
	}
	if exists, _ := mysqlTableExists(db, "sku_mappings"); exists {
		t.Fatal("旧 sku_mappings 应已删除")
	}
	if exists, _ := mysqlTableExists(db, "sku_mappings_v3_backup"); !exists {
		t.Fatal("删除旧表前必须保留受限备份表")
	}
}

func TestMySQLMigrate_V3三个中断点重跑收敛(t *testing.T) {
	for _, tc := range []struct {
		name    string
		prepare func(*testing.T, *sql.DB)
	}{
		{"DDL完成回填未开始", func(t *testing.T, db *sql.DB) {
			if err := ensureMySQLV3Columns(db); err != nil {
				t.Fatal(err)
			}
			mustExec(t, db, mysqlSchemaV3SpecMappings)
		}},
		{"回填到一半", func(t *testing.T, db *sql.DB) {
			if err := ensureMySQLV3Columns(db); err != nil {
				t.Fatal(err)
			}
			mustExec(t, db, mysqlSchemaV3SpecMappings)
			key, _ := spec.SpecKey("黑色,M")
			mustExec(t, db, `UPDATE syb_orders SET spec_key=? WHERE syb_id='SYB-A'`, key)
		}},
		{"全部完成版本未记录", func(t *testing.T, db *sql.DB) {
			if err := migrateMySQLV3(db); err != nil {
				t.Fatal(err)
			}
		}},
	} {
		t.Run(tc.name, func(t *testing.T) {
			db := openMySQLMigrationTestDB(t)
			defer db.Close()
			cleanMySQLTestSchema(t, db)
			defer cleanMySQLTestSchema(t, db)
			prepareMySQLV2(t, db)
			now := "2026-08-10T03:00:00Z"
			mustExec(t, db, `INSERT INTO syb_orders (syb_id,order_no,title,shopee_goods_id,product_spec,quantity,syb_data,created_at,updated_at) VALUES ('SYB-A','A','A','G-A','黑色,M',1,'{}',?,?),('SYB-B','B','B','G-B','白色,L',1,'{}',?,?)`, now, now, now, now)
			tc.prepare(t, db)
			if err := MigrateMySQL(db); err != nil {
				t.Fatalf("重跑失败: %v", err)
			}
			if err := MigrateMySQL(db); err != nil {
				t.Fatalf("再次重跑失败: %v", err)
			}
			var count int
			if err := db.QueryRow(`SELECT COUNT(*) FROM syb_orders WHERE spec_key IS NOT NULL`).Scan(&count); err != nil || count != 2 {
				t.Fatalf("回填未收敛 count=%d err=%v", count, err)
			}
		})
	}
}

func TestMySQLMigrate_V3字段存在但约束缺失可收敛(t *testing.T) {
	db := openMySQLMigrationTestDB(t)
	defer db.Close()
	cleanMySQLTestSchema(t, db)
	defer cleanMySQLTestSchema(t, db)
	prepareMySQLV2(t, db)
	mustExec(t, db, `INSERT INTO shopee_products(goods_id,title,created_at,updated_at) VALUES ('EXISTING-1','存量商品','2026-08-10T00:00:00Z','2026-08-10T00:00:00Z')`)
	mustExec(t, db, `ALTER TABLE shopee_products ADD COLUMN source VARCHAR(16) NULL`)
	if err := MigrateMySQL(db); err != nil {
		t.Fatal(err)
	}
	var existingSource string
	if err := db.QueryRow(`SELECT source FROM shopee_products WHERE goods_id='EXISTING-1'`).Scan(&existingSource); err != nil || existingSource != "report" {
		t.Fatalf("可空 source 中断点的存量行未收敛: source=%q err=%v", existingSource, err)
	}
	mustExec(t, db, `INSERT INTO shopee_products(goods_id,title,source,created_at,updated_at) VALUES ('CHECK-1','检查','report','2026-08-10T00:00:00Z','2026-08-10T00:00:00Z')`)
	if _, err := db.Exec(`UPDATE shopee_products SET source='typo'`); err == nil {
		t.Fatal("source CHECK 必须拒绝非法值")
	}
}

func TestMySQLMigrate_V3形状自检失败不记版本(t *testing.T) {
	db := openMySQLMigrationTestDB(t)
	defer db.Close()
	cleanMySQLTestSchema(t, db)
	defer cleanMySQLTestSchema(t, db)
	prepareMySQLV2(t, db)
	mustExec(t, db, `CREATE TABLE spec_mappings (
		shopee_goods_id VARCHAR(191) NOT NULL,
		spec_key VARCHAR(191) NOT NULL,
		pdd_goods_id VARCHAR(191) NOT NULL,
		pdd_option_key VARCHAR(191) NOT NULL,
		pdd_options LONGTEXT NOT NULL,
		spec_raw TEXT NOT NULL,
		mapped_at VARCHAR(35) NOT NULL,
		PRIMARY KEY (shopee_goods_id, pdd_goods_id, spec_key)
	) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4`)
	if err := MigrateMySQL(db); err == nil {
		t.Fatal("错误主键顺序必须让 v3 形状自检失败")
	}
	var count int
	if err := db.QueryRow(`SELECT COUNT(*) FROM schema_migrations WHERE version=3`).Scan(&count); err != nil || count != 0 {
		t.Fatalf("自检失败时不得记录 v3: count=%d err=%v", count, err)
	}
}

func TestMySQLMigrate_V3升级V4且断点重跑(t *testing.T) {
	db := openMySQLMigrationTestDB(t)
	defer db.Close()
	cleanMySQLTestSchema(t, db)
	defer cleanMySQLTestSchema(t, db)
	prepareMySQLV2(t, db)
	if err := migrateMySQLV3(db); err != nil {
		t.Fatal(err)
	}
	mustExec(t, db, `INSERT INTO schema_migrations(version,applied_at) VALUES (3,'2026-08-10T00:00:00Z')`)
	// 模拟 DDL 已完成、版本未记录。
	mustExec(t, db, mysqlSchemaV4Decisions)
	if err := MigrateMySQL(db); err != nil {
		t.Fatal(err)
	}
	if err := MigrateMySQL(db); err != nil {
		t.Fatalf("重跑失败: %v", err)
	}
	var versions int
	if err := db.QueryRow(`SELECT COUNT(*) FROM schema_migrations WHERE version=4`).Scan(&versions); err != nil || versions != 1 {
		t.Fatalf("v4=%d err=%v", versions, err)
	}
	mustExec(t, db, `INSERT INTO spec_mapping_decisions(shopee_goods_id,spec_key,pdd_goods_id,rules_version,chosen_option_key,accepted,decided_at) VALUES('S','K','P','rules_v1','O',1,'2026-08-10T00:00:00Z')`)
	if _, err := db.Exec(`UPDATE spec_mapping_decisions SET accepted=2`); err == nil {
		t.Fatal("accepted CHECK 必须拒绝 2")
	}
}

func TestMySQLMigrate_V4形状错误不记版本(t *testing.T) {
	db := openMySQLMigrationTestDB(t)
	defer db.Close()
	cleanMySQLTestSchema(t, db)
	defer cleanMySQLTestSchema(t, db)
	prepareMySQLV2(t, db)
	if err := migrateMySQLV3(db); err != nil {
		t.Fatal(err)
	}
	mustExec(t, db, `INSERT INTO schema_migrations(version,applied_at) VALUES (3,'2026-08-10T00:00:00Z')`)
	mustExec(t, db, strings.Replace(mysqlSchemaV4Decisions, "CHECK (accepted IN (0,1))", "CHECK (accepted IN (0,1,2))", 1))
	if err := MigrateMySQL(db); err == nil {
		t.Fatal("错误 CHECK 必须阻止 v4")
	}
	var count int
	db.QueryRow(`SELECT COUNT(*) FROM schema_migrations WHERE version=4`).Scan(&count)
	if count != 0 {
		t.Fatal("自检失败不得记 v4")
	}
}

func openMySQLMigrationTestDB(t *testing.T) *sql.DB {
	t.Helper()
	if os.Getenv("CMAUTOBUY_MYSQL_TEST") != "1" {
		t.Skip("未启用真实 MySQL 8 集成测试")
	}
	cfg, err := config.LoadDatabaseFromEnv()
	if err != nil {
		t.Fatal(err)
	}
	if !strings.HasSuffix(cfg.Name, "_test") {
		t.Fatalf("拒绝使用非 _test 数据库 %q", cfg.Name)
	}
	db, err := OpenMySQL(cfg)
	if err != nil {
		t.Fatal(err)
	}
	return db
}

func prepareMySQLV2(t *testing.T, db *sql.DB) {
	t.Helper()
	mustExec(t, db, `CREATE TABLE schema_migrations (version INT PRIMARY KEY, applied_at VARCHAR(35) NOT NULL) ENGINE=InnoDB`)
	for _, statement := range mysqlSchemaV1 {
		mustExec(t, db, statement)
	}
	for _, statement := range mysqlSchemaV2 {
		mustExec(t, db, statement)
	}
	mustExec(t, db, `INSERT INTO schema_migrations(version,applied_at) VALUES (1,'2026-08-10T00:00:00Z'),(2,'2026-08-10T00:00:00Z')`)
}

func mustExec(t *testing.T, db *sql.DB, query string, args ...any) {
	t.Helper()
	if _, err := db.Exec(query, args...); err != nil {
		t.Fatalf("执行 SQL 失败: %v", err)
	}
}

func cleanMySQLTestSchema(t *testing.T, db *sql.DB) {
	t.Helper()
	rows, err := db.Query(`SELECT table_name FROM information_schema.tables
		WHERE table_schema = DATABASE() AND table_type = 'BASE TABLE'`)
	if err != nil {
		t.Fatal(err)
	}
	var tables []string
	for rows.Next() {
		var table string
		if err := rows.Scan(&table); err != nil {
			rows.Close()
			t.Fatal(err)
		}
		tables = append(tables, table)
	}
	if err := rows.Close(); err != nil {
		t.Fatal(err)
	}
	if _, err := db.Exec(`SET FOREIGN_KEY_CHECKS = 0`); err != nil {
		t.Fatal(err)
	}
	defer db.Exec(`SET FOREIGN_KEY_CHECKS = 1`)
	for _, table := range tables {
		// 表名只来自当前 _test 数据库的 information_schema，并对反引号转义。
		quoted := "`" + strings.ReplaceAll(table, "`", "``") + "`"
		if _, err := db.Exec("DROP TABLE " + quoted); err != nil {
			t.Fatal(fmt.Errorf("清理 MySQL 测试表 %s 失败: %w", table, err))
		}
	}
}