// SPDX-FileCopyrightText: 2025 Romain Maneschi <romain@gitroot.dev>
//
// SPDX-License-Identifier: EUPL-1.2

package repository

import (
	"context"
	"fmt"
	"testing"

	"github.com/go-git/go-git/v6/plumbing"
	"gitroot.dev/server/configuration"
	"gitroot.dev/server/logger"
	"gitroot.dev/server/user"
)

// | commit5
// | | - commit4 -- branch2
// | | commit3
// | - commit2 -- branch1
// - commit1
// - init -- main
func TestFoundAncestor(t *testing.T) {
	dataDir := t.TempDir()
	conf := configuration.NewConfiguration(dataDir)
	userManager, _ := user.NewManager(conf)
	m := NewManager(conf, userManager)
	err := m.CreateUserRepo(context.TODO(), RepoConf{Name: "foundAncestor", DefaultBranch: "main"}, []user.SimpleUser{}, []byte(""))
	if err != nil {
		t.Fatal(err)
	}
	repo, err := m.Open(context.TODO(), "foundAncestor")
	if err != nil {
		t.Fatal(err)
	}
	repoWriter, err := repo.WillWrite(plumbing.HEAD)
	if err != nil {
		t.Fatal(err)
	}
	h1 := makeCommit(repoWriter, 1, t, userManager)
	if err := repoWriter.Branch("branch1", h1); err != nil {
		t.Fatal(err)
	}
	h2 := makeCommit(repoWriter, 2, t, userManager)
	com2, _ := repoWriter.repoWrite.CommitObject(h2)
	comAncestor, _ := foundAncestor(repoWriter.repoWrite, logger.NewLogger("test"), RepoConfiguration{DefaultBranch: "main"}, com2)
	if comAncestor.Hash != h1 {
		t.Fatal("should be h1")
	}
	h3 := makeCommit(repoWriter, 3, t, userManager)
	if err := repoWriter.Branch("branch2", h3); err != nil {
		t.Fatal(err)
	}
	h4 := makeCommit(repoWriter, 4, t, userManager)
	com4, _ := repoWriter.repoWrite.CommitObject(h4)
	comAncestor4, _ := foundAncestor(repoWriter.repoWrite, logger.NewLogger("test"), RepoConfiguration{DefaultBranch: "main"}, com4)
	if comAncestor4.Hash != h3 {
		t.Fatal("should be h3", comAncestor4.Hash, h1, h2, h3)
	}
	if err := repoWriter.Checkout(plumbing.NewBranchReferenceName("main")); err != nil {
		t.Fatal(err)
	}
	// h5 := makeCommit(repoWriter, 5, t, userManager)
	// comAncestor5, _ := foundAncestor(repoWriter.repoWrite, logger.NewLogger("test"), RepoConfiguration{DefaultBranch: "main"}, com2)
	// if comAncestor5.Hash != h1 {
	// 	t.Fatal("should be h1", comAncestor5.Hash, h1, h2, h3, h4, h5)
	// }
	repo.Close()
}

func makeCommit(repo *GitRootRepositoryWrite, nb int, t *testing.T, u *user.Manager) plumbing.Hash {
	if err := repo.Write("README.md", []byte(fmt.Sprintf("commit%d", nb))); err != nil {
		t.Fatal(err)
	}
	h, err := repo.CommitAll(fmt.Sprintf("commit%d", nb), u.RootCommiter())
	if err != nil {
		t.Fatal(err)
	}
	return h
}