package sync

import (
	"bytes"
	"encoding/base64"
	"log"
	"os"
	"os/exec"
	"path/filepath"
	"strings"
	"testing"
)

// R-616: the catalog credentials must never be stored in the clone. A fake https remote is served from
// a local repository through git's own url.<base>.insteadOf (in a test-only HOME), so the real clone
// and fetch paths run with no network: git REWRITES the URL it dials but STORES the URL it was given —
// which is exactly the URL the product chose, credentialed or not.
func r616Fixture(t *testing.T) (s *Syncer, logs *bytes.Buffer, src string) {
	t.Helper()
	if _, err := exec.LookPath("git"); err != nil {
		t.Skip("git not on PATH")
	}
	root := t.TempDir()
	src = filepath.Join(root, "src")
	run := func(dir string, args ...string) {
		t.Helper()
		cmd := exec.Command("git", args...)
		cmd.Dir = dir
		if out, err := cmd.CombinedOutput(); err != nil {
			t.Fatalf("git %v: %v\n%s", args, err, out)
		}
	}
	home := filepath.Join(root, "home")
	os.MkdirAll(home, 0o755)
	t.Setenv("HOME", home)
	t.Setenv("XDG_CONFIG_HOME", filepath.Join(home, ".config"))
	t.Setenv("GIT_CONFIG_NOSYSTEM", "1")
	gitcfg := "[user]\n\tname = t\n\temail = t@example.invalid\n" +
		"[url \"file://" + src + "\"]\n" +
		"\tinsteadOf = https://user:tok-SECRET@catalog.example.invalid/admin/catalog.git\n" +
		"\tinsteadOf = https://catalog.example.invalid/admin/catalog.git\n"
	if err := os.WriteFile(filepath.Join(home, ".gitconfig"), []byte(gitcfg), 0o644); err != nil {
		t.Fatal(err)
	}
	os.MkdirAll(src, 0o755)
	run(src, "init", "-q", "-b", "main")
	os.WriteFile(filepath.Join(src, "README"), []byte("x\n"), 0o644)
	run(src, "add", "README")
	run(src, "commit", "-q", "-m", "init")

	s = newTestSyncer(t, "https://catalog.example.invalid/admin/catalog.git")
	s.cfg.Git.Username = "user"
	s.cfg.Git.Token = "tok-SECRET"
	logs = &bytes.Buffer{}
	s.logger = log.New(logs, "", 0)
	return s, logs, src
}

func storedOrigin(t *testing.T, dir string) string {
	t.Helper()
	out, err := exec.Command("git", "-C", dir, "config", "--get", "remote.origin.url").Output()
	if err != nil {
		t.Fatalf("read origin: %v", err)
	}
	return strings.TrimSpace(string(out))
}

func TestR616_CloneStoresNoCredentials(t *testing.T) {
	s, logs, _ := r616Fixture(t)
	if err := s.gitCloneOrPull(); err != nil {
		t.Fatalf("clone: %v", err)
	}
	origin := storedOrigin(t, s.cacheDir)
	if strings.Contains(origin, "@") || strings.Contains(origin, "tok-SECRET") {
		t.Errorf("the clone's stored origin carries credentials: %q", origin)
	}
	cfgBytes, _ := os.ReadFile(filepath.Join(s.cacheDir, ".git", "config"))
	if strings.Contains(string(cfgBytes), "tok-SECRET") {
		t.Errorf(".git/config holds the token in the clear:\n%s", cfgBytes)
	}
	// A pull (fetch + reset) still works on the clean clone.
	if err := s.gitCloneOrPull(); err != nil {
		t.Fatalf("pull: %v", err)
	}
	if strings.Contains(logs.String(), "tok-SECRET") {
		t.Errorf("the token reached the log:\n%s", logs.String())
	}
}

// A clone made BEFORE the fix (origin with userinfo) is scrubbed on the next pull.
func TestR616_PreFixCloneIsScrubbedOnPull(t *testing.T) {
	s, logs, _ := r616Fixture(t)
	cmd := exec.Command("git", "clone", "-q", "--depth", "1", "--branch", "main",
		"https://user:tok-SECRET@catalog.example.invalid/admin/catalog.git", s.cacheDir)
	if out, err := cmd.CombinedOutput(); err != nil {
		t.Fatalf("pre-fix clone: %v\n%s", err, out)
	}
	if !strings.Contains(storedOrigin(t, s.cacheDir), "tok-SECRET") {
		t.Fatal("fixture: the pre-fix clone should carry the token")
	}
	if err := s.gitCloneOrPull(); err != nil {
		t.Fatalf("pull: %v", err)
	}
	if got := storedOrigin(t, s.cacheDir); got != "https://catalog.example.invalid/admin/catalog.git" {
		t.Errorf("stored origin not scrubbed: %q", got)
	}
	if strings.Contains(logs.String(), "tok-SECRET") {
		t.Errorf("the token reached the log:\n%s", logs.String())
	}
}

// The credentials still reach git: the header is scoped to the remote's origin and carries the same
// Basic pair the URL form sent. Checked with git's own URL matcher, no network.
func TestR616_AuthHeaderScopedToTheRemote(t *testing.T) {
	if _, err := exec.LookPath("git"); err != nil {
		t.Skip("git not on PATH")
	}
	s := newTestSyncer(t, "https://catalog.example.invalid/admin/catalog.git")
	if env := s.gitAuthEnv(); env != nil {
		t.Errorf("no credentials configured -> no auth env, got %v", env)
	}
	s.cfg.Git.Username, s.cfg.Git.Token = "user", "tok-SECRET"
	env := s.gitAuthEnv()
	want := "Authorization: Basic " + base64.StdEncoding.EncodeToString([]byte("user:tok-SECRET"))
	match := func(url string) string {
		cmd := exec.Command("git", "config", "--get-urlmatch", "http.extraHeader", url)
		cmd.Env = append(os.Environ(), env...)
		out, _ := cmd.Output()
		return strings.TrimSpace(string(out))
	}
	t.Setenv("GIT_CONFIG_NOSYSTEM", "1")
	t.Setenv("HOME", t.TempDir())
	if got := match("https://catalog.example.invalid/admin/catalog.git"); got != want {
		t.Errorf("header for the remote = %q, want the Basic pair", got)
	}
	if got := match("https://other.example.invalid/x.git"); got != "" {
		t.Errorf("the header must not reach another host, got %q", got)
	}
	s.cfg.Git.RepoURL = "/local/path/catalog"
	if env := s.gitAuthEnv(); env != nil {
		t.Errorf("a non-https remote gets no auth env, got %v", env)
	}
}

// R-616 × R-615: with a token set and the SAME repository configured, repeated syncs never re-clone
// (the configured URL carries no credentials to differ from the stored origin) and the stored origin
// stays free of '@'. A re-clone is detected by a marker file planted inside the cache: RemoveAll would
// take it with it.
func TestR616_TokenSetSameRepoNoRecloneOriginClean(t *testing.T) {
	s, logs, _ := r616Fixture(t)
	if err := s.gitCloneOrPull(); err != nil {
		t.Fatalf("clone: %v", err)
	}
	marker := filepath.Join(s.cacheDir, ".git", "r616-no-reclone")
	if err := os.WriteFile(marker, []byte("x"), 0o644); err != nil {
		t.Fatal(err)
	}
	for i := 0; i < 3; i++ {
		if err := s.gitCloneOrPull(); err != nil {
			t.Fatalf("pull %d: %v", i, err)
		}
	}
	if _, err := os.Stat(marker); err != nil {
		t.Error("the cache was RE-CLONED on a same-repo sync with a token set")
	}
	if o := storedOrigin(t, s.cacheDir); strings.Contains(o, "@") {
		t.Errorf("stored origin carries credentials: %q", o)
	}
	if strings.Contains(logs.String(), "re-cloning") || strings.Contains(logs.String(), "tok-SECRET") {
		t.Errorf("unexpected re-clone or token in the log:\n%s", logs.String())
	}
}