package core_test

import (
	"bytes"
	"os"
	"path/filepath"
	"testing"
	"time"

	"git.hrafn.xyz/aether/gosick/internal/homesick/core"
	git "github.com/go-git/go-git/v5"
	"github.com/go-git/go-git/v5/plumbing/object"
	"github.com/stretchr/testify/require"
	"github.com/stretchr/testify/suite"
)

type DiffSuite struct {
	suite.Suite
	tmpDir   string
	homeDir  string
	reposDir string
	stdout   *bytes.Buffer
	stderr   *bytes.Buffer
	app      *core.App
}

func TestDiffSuite(t *testing.T) {
	suite.Run(t, new(DiffSuite))
}

func (s *DiffSuite) SetupTest() {
	s.tmpDir = s.T().TempDir()
	s.homeDir = filepath.Join(s.tmpDir, "home")
	s.reposDir = filepath.Join(s.homeDir, ".homesick", "repos")
	require.NoError(s.T(), os.MkdirAll(s.reposDir, 0o755))

	s.stdout = &bytes.Buffer{}
	s.stderr = &bytes.Buffer{}
	s.app = &core.App{
		HomeDir:  s.homeDir,
		ReposDir: s.reposDir,
		Stdout:   s.stdout,
		Stderr:   s.stderr,
	}
}

func (s *DiffSuite) createCastleRepo(castle string) string {
	castleRoot := filepath.Join(s.reposDir, castle)
	repo, err := git.PlainInit(castleRoot, false)
	require.NoError(s.T(), err)

	filePath := filepath.Join(castleRoot, "home", ".vimrc")
	require.NoError(s.T(), os.MkdirAll(filepath.Dir(filePath), 0o755))
	require.NoError(s.T(), os.WriteFile(filePath, []byte("set number\n"), 0o644))

	wt, err := repo.Worktree()
	require.NoError(s.T(), err)
	_, err = wt.Add("home/.vimrc")
	require.NoError(s.T(), err)
	_, err = wt.Commit("initial", &git.CommitOptions{Author: &object.Signature{
		Name:  "Behavior Test",
		Email: "behavior@test.local",
		When:  time.Now(),
	}})
	require.NoError(s.T(), err)

	return castleRoot
}

func (s *DiffSuite) TestDiff_WritesGitDiffToAppStdout() {
	castleRoot := s.createCastleRepo("castle_repo")
	require.NoError(s.T(), os.WriteFile(filepath.Join(castleRoot, "home", ".vimrc"), []byte("changed\n"), 0o644))

	require.NoError(s.T(), s.app.Diff("castle_repo"))
	require.Contains(s.T(), s.stdout.String(), "diff --git")
}