package environment

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

// 迁移文件一旦按版本号记录进 schema_migration 就不会再执行。
// 内容修正是用版本号不变的方式提交的话，已 applied 的库永远拿不到修正，
// 造成不同库 schema 漂移（034 曾因此漏删 browser_env.image_version，
// 触发 "environment persistence operation failed"）。
// 本测试锁死规则：迁移文件内容自引入起不可变更；要改就新增版本号。
func TestMigrationFilesAreImmutableAfterIntroduction(t *testing.T) {
	// 迁移文件相对本包的路径 → 仓库根相对路径（git show 需要仓库根路径）。
	repoPath := map[string]string{
		"migrations/*.sql":            "internal/environment",
		"../creator/migrations/*.sql": "internal/creator",
		"../account/migrations/*.sql": "internal/account",
	}
	for pattern, repoDir := range repoPath {
		entries, err := filepath.Glob(pattern)
		if err != nil {
			t.Fatalf("list migrations for %s: %v", pattern, err)
		}
		for _, file := range entries {
			// repoDir 已是仓库根相对包目录，glob 出的文件按 basename 拼回。<pkg>/migrations/<name>.sql
			file, repoFile := file, repoDir+"/migrations/"+filepath.Base(file)
			t.Run(file, func(t *testing.T) {
				introduced := gitOutput(t, "log", "--format=%H", "--diff-filter=A", "--", repoFile)
				if introduced == "" {
					t.Skipf("no introducing commit found for %s", repoFile)
				}
				firstCommit := strings.SplitN(introduced, "\n", 2)[0]
				original := gitOutput(t, "show", firstCommit+":"+repoFile)
				current, err := os.ReadFile(file)
				if err != nil {
					t.Fatalf("read %s: %v", file, err)
				}
				if original != string(current) {
					t.Errorf("migration %s was modified after introduction in %s; migrations are immutable — add a new versioned migration instead", repoFile, firstCommit)
				}
			})
		}
	}
}

func gitOutput(t *testing.T, args ...string) string {
	t.Helper()
	cmd := exec.Command("git", args...)
	cmd.Dir = repoRoot(t)
	out, err := cmd.Output()
	if err != nil {
		t.Skipf("git %s unavailable: %v", args[0], err)
	}
	return string(out)
}

// repoRoot 定位 git 仓库根，保证 glob 出的包相对路径都能转成仓库根相对路径。
func repoRoot(t *testing.T) string {
	t.Helper()
	out, err := exec.Command("git", "rev-parse", "--show-toplevel").Output()
	if err != nil {
		t.Skipf("git repository unavailable: %v", err)
	}
	return strings.TrimSpace(string(out))
}