package migrate

import (
	"database/sql"
	"path/filepath"
	"strings"
	"testing"

	_ "git.ycl.pub/yl32940/TsDB2/DB/driver"
)

// 现场复验: 59566B 的 TEXT param → 迁成 Blob → 驱动分页查询读回逐字节一致。
func TestBlobPagingRepro(t *testing.T) {
	dir := t.TempDir()
	srcPath := filepath.Join(dir, "src.sqlite")
	src, err := OpenSQLite(srcPath, quiet())
	if err != nil {
		t.Fatal(err)
	}
	big := strings.Repeat("P", 59566)
	if _, err := src.db.Exec(`CREATE TABLE "sys_logs" ("id" INTEGER PRIMARY KEY, "param" TEXT, "msg" TEXT)`); err != nil {
		t.Fatal(err)
	}
	for i := 1; i <= 20; i++ {
		p := big
		if i == 7 {
			p = "small"
		}
		if _, err := src.db.Exec(`INSERT INTO "sys_logs" (id, param, msg) VALUES (?, ?, ?)`, i, p, "m"); err != nil {
			t.Fatal(err)
		}
	}
	src.Close()

	dstPath := filepath.Join(dir, "dst.db")
	s, _ := OpenSQLite(srcPath, quiet())
	d, _ := OpenVRTX(dstPath, quiet())
	if _, err := Run(s, d, quiet()); err != nil {
		t.Fatal(err)
	}
	d.Close()
	s.Close()

	// 分页查询形态 (LIMIT/OFFSET 翻页读完 20 行, 每页 7 行)
	vdb, err := sql.Open("vrtx", dstPath)
	if err != nil {
		t.Fatal(err)
	}
	defer vdb.Close()
	var got []string
	for page := 0; page < 3; page++ {
		rows, err := vdb.Query(`SELECT id, param FROM sys_logs ORDER BY id LIMIT 7 OFFSET ?`, page*7)
		if err != nil {
			t.Fatalf("分页查询: %v", err)
		}
		for rows.Next() {
			var id int
			var p []byte
			if err := rows.Scan(&id, &p); err != nil {
				t.Fatalf("读取 BLOB 列 param: %v", err)
			}
			got = append(got, string(p))
		}
		rows.Close()
	}
	if len(got) != 20 {
		t.Fatalf("行数 %d", len(got))
	}
	for i, g := range got {
		want := big
		if i == 6 {
			want = "small"
		}
		if g != want {
			t.Fatalf("第 %d 行 param 不一致 (len=%d want %d)", i+1, len(g), len(want))
		}
	}
	t.Logf("20 行分页读回全部逐字节一致 (含 59566B 大 blob ×19)")
}