package db

import (
	"context"
	"os"
	"path/filepath"
	"strings"
	"testing"
)

// newSQLiteFile 建一个 sqlite 测试库文件并执行建表/插数语句,返回 ConnReq。
func newSQLiteFile(t *testing.T, stmts ...string) ConnReq {
	t.Helper()
	path := filepath.Join(t.TempDir(), "test.db")
	if err := os.WriteFile(path, []byte{}, 0600); err != nil {
		t.Fatal(err)
	}
	for _, s := range stmts {
		res := ExecSQL(context.Background(), ConnReq{Driver: "sqlite", Database: path, SQL: s})
		if res.Error != "" {
			t.Fatalf("初始化语句失败 %q: %s", s, res.Error)
		}
	}
	return ConnReq{Driver: "sqlite", Database: path}
}

// R2-B5:sqlite 返回 sqlite_master 中的原始建表语句。
func TestGetDDLSQLite(t *testing.T) {
	c := newSQLiteFile(t, `CREATE TABLE t_person (id INTEGER PRIMARY KEY, name TEXT NOT NULL, age INTEGER)`)
	c.Table = "t_person"
	ddl, err := GetDDL(context.Background(), c)
	if err != nil {
		t.Fatal(err)
	}
	if !strings.Contains(ddl, "CREATE TABLE t_person") || !strings.Contains(ddl, "name TEXT") {
		t.Fatalf("DDL 内容不符: %s", ddl)
	}

	c.Table = "no_such_table"
	if _, err := GetDDL(context.Background(), c); err == nil {
		t.Fatal("不存在的表应报错")
	}
}

func TestGetDDLRedis(t *testing.T) {
	_, err := GetDDL(context.Background(), ConnReq{Driver: "redis", Table: "k"})
	if err == nil || !strings.Contains(err.Error(), "不支持") {
		t.Fatalf("redis 应报不支持: %v", err)
	}
}

func TestGetDDLMissingTable(t *testing.T) {
	_, err := GetDDL(context.Background(), ConnReq{Driver: "sqlite", Table: ""})
	if err == nil {
		t.Fatal("空表名应报错")
	}
}

// R2-B5:pg/mssql/oracle 族用列元数据拼装,各 family 引号不同。
func TestBuildDDLFromColumns(t *testing.T) {
	cols := []ColumnInfo{
		{Name: "id", Type: "integer", Nullable: false, Key: "PRI"},
		{Name: "na\"me", Type: "text", Nullable: true},
	}
	// pg:双引号加倍
	ddl, err := buildDDLFromColumns("postgres", "public.t", cols)
	if err != nil {
		t.Fatal(err)
	}
	if !strings.Contains(ddl, `"public"."t"`) || !strings.Contains(ddl, `"na""me" text`) ||
		!strings.Contains(ddl, `"id" integer NOT NULL,`) || !strings.Contains(ddl, `PRIMARY KEY ("id")`) {
		t.Fatalf("pg DDL 不符:\n%s", ddl)
	}
	// mssql:中括号
	ddl, err = buildDDLFromColumns("mssql", "dbo.t", cols)
	if err != nil {
		t.Fatal(err)
	}
	if !strings.Contains(ddl, `[id] integer NOT NULL`) || !strings.Contains(ddl, `PRIMARY KEY ([id])`) {
		t.Fatalf("mssql DDL 不符:\n%s", ddl)
	}
	// oracle:原名
	ddl, err = buildDDLFromColumns("oracle", "T", cols)
	if err != nil {
		t.Fatal(err)
	}
	if !strings.Contains(ddl, `CREATE TABLE T (`) || !strings.Contains(ddl, `PRIMARY KEY (id)`) {
		t.Fatalf("oracle DDL 不符:\n%s", ddl)
	}
	// 无列报错
	if _, err := buildDDLFromColumns("postgres", "t", nil); err == nil {
		t.Fatal("无列应报错")
	}
}