package archive

import (
	"archive/tar"
	"bytes"
	"io"
	"os"
	"os/exec"
	"path/filepath"
	"testing"

	"github.com/klauspost/compress/zstd"
)

func TestBuildSourceArchive_RoundTrip(t *testing.T) {
	dir := t.TempDir()
	run := func(name string, args ...string) {
		t.Helper()
		cmd := exec.Command(name, args...)
		cmd.Dir = dir
		cmd.Env = append(os.Environ(),
			"GIT_AUTHOR_NAME=t",
			"GIT_AUTHOR_EMAIL=t@t",
			"GIT_COMMITTER_NAME=t",
			"GIT_COMMITTER_EMAIL=t@t",
		)
		out, err := cmd.CombinedOutput()
		if err != nil {
			t.Fatalf("%s %v: %v\n%s", name, args, err, out)
		}
	}
	run("git", "init", "-q")
	if err := os.WriteFile(filepath.Join(dir, "plugin.mod"),
		[]byte("[plugin]\nname=\"x\"\nscope=\"@s\"\nversion=\"0.1.0\"\n"), 0o644); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(filepath.Join(dir, "ignored.log"), []byte("nope"), 0o644); err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(filepath.Join(dir, ".gitignore"), []byte("ignored.log\n"), 0o644); err != nil {
		t.Fatal(err)
	}
	run("git", "add", "plugin.mod", ".gitignore")
	run("git", "commit", "-qm", "init")

	zstdBytes, err := BuildSourceArchive(dir)
	if err != nil {
		t.Fatalf("BuildSourceArchive: %v", err)
	}
	if len(zstdBytes) == 0 {
		t.Fatal("empty archive")
	}

	dec, err := zstd.NewReader(bytes.NewReader(zstdBytes))
	if err != nil {
		t.Fatal(err)
	}
	defer dec.Close()
	tr := tar.NewReader(dec)
	got := map[string]string{}
	for {
		hdr, err := tr.Next()
		if err == io.EOF {
			break
		}
		if err != nil {
			t.Fatal(err)
		}
		buf, err := io.ReadAll(tr)
		if err != nil {
			t.Fatal(err)
		}
		got[hdr.Name] = string(buf)
	}
	if _, ok := got["plugin.mod"]; !ok {
		t.Errorf("expected plugin.mod in archive, got %v", keys(got))
	}
	if _, ok := got["ignored.log"]; ok {
		t.Errorf("ignored.log should not be in archive (gitignored + untracked)")
	}
}

func keys(m map[string]string) []string {
	out := make([]string, 0, len(m))
	for k := range m {
		out = append(out, k)
	}
	return out
}