//go:build integration

package main

// The fetch step's merge on real git repositories (issue 1676); preview_test.go proves the commands with a fake runner.

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

	"git.novox.be/novox/mesh-sdk/go/buildstep"
	"git.novox.be/novox/mesh-sdk/go/forgekey"
)

func git(t *testing.T, dir string, args ...string) string {
	t.Helper()
	cmd := exec.Command("git", append([]string{"-C", dir, "-c", "user.name=t", "-c", "user.email=t@example.invalid", "-c", "commit.gpgsign=false"}, args...)...)
	out, err := cmd.CombinedOutput()
	if err != nil {
		t.Fatalf("git %v: %v\n%s", args, err, out)
	}
	return strings.TrimSpace(string(out))
}

func TestRealFetchMergesAConflictAndAPlainFetch(t *testing.T) {
	root := t.TempDir()
	bare, work := filepath.Join(root, "forge", "o", "r.git"), filepath.Join(root, "work")
	os.MkdirAll(bare, 0o755)
	os.MkdirAll(work, 0o755)
	git(t, bare, "init", "-q", "--bare")
	git(t, work, "init", "-q", "-b", "main")
	files := typeScriptModule(`{"dependencies":{"@novox/mesh-sdk":"^0.1.6"}}`)
	files["a.txt"] = "one\ntwo\nthree\n"
	for n, c := range files {
		write(t, filepath.Join(work, n), c, 0o644)
	}
	git(t, work, "add", ".")
	git(t, work, "commit", "-q", "-m", "fork")
	fork := git(t, work, "rev-parse", "HEAD")
	change := func(from, ref string, f map[string]string) string {
		git(t, work, "checkout", "-q", "-B", "tmp", from)
		for n, c := range f {
			write(t, filepath.Join(work, n), c, 0o644)
		}
		git(t, work, "add", ".")
		git(t, work, "commit", "-q", "-m", "c")
		git(t, work, "push", "-q", "-f", bare, "HEAD:"+ref)
		return git(t, work, "rev-parse", "HEAD")
	}
	trunk := change(fork, "refs/heads/main", map[string]string{"a.txt": "one\ntwo\nTRUNK\n"})
	clean := change(fork, "refs/pull/1/head", map[string]string{"modules/m/extra.ts": "export {}\n"})
	clash := change(fork, "refs/pull/2/head", map[string]string{"a.txt": "one\ntwo\nHEAD\n"})

	m, _, _ := newMachine(t)
	m.Run = forgekey.ExecRunner
	m.RemoteBase = "file://" + filepath.Join(root, "forge") + "/"
	m.FetchOptions = []buildstep.Option{buildstep.AllowFileRemote()}

	out, err := m.fetch(context.Background(), map[string]any{"repository": "o/r", "commit": clean, "ref": "refs/pull/1/head", "base": trunk})
	if err != nil {
		t.Fatal(err)
	}
	r := out.(FetchResult)
	tree := filepath.Join(m.Work, r.Workspace, "tree")
	if r.Merge == "" || strings.Join(r.Changed, ",") != "modules/m/extra.ts" || len(r.Conflicts) != 0 || len(r.Modules) != 1 {
		t.Fatalf("clean: %+v", r)
	}
	if want := git(t, tree, "rev-parse", r.Merge+":modules/m"); r.Trees["modules/m"].Tree != want {
		t.Errorf("tree = %s, want %s", r.Trees["modules/m"].Tree, want)
	}
	if got := git(t, tree, "rev-parse", "HEAD"); got != r.Merge {
		t.Errorf("the workspace is at %s, want the merge %s", got, r.Merge)
	}

	out, err = m.fetch(context.Background(), map[string]any{"repository": "o/r", "commit": clash, "ref": "refs/pull/2/head", "base": trunk})
	if err != nil {
		t.Fatalf("a conflict failed the step: %v", err)
	}
	r = out.(FetchResult)
	if r.Merge != "" || strings.Join(r.Conflicts, ",") != "a.txt" {
		t.Fatalf("conflict: %+v", r)
	}
	if got := git(t, filepath.Join(m.Work, r.Workspace, "tree"), "rev-parse", "HEAD"); got != trunk {
		t.Errorf("after a conflict the workspace is at %s, want the trunk %s", got, trunk)
	}

	out, err = m.fetch(context.Background(), map[string]any{"repository": "o/r", "commit": clean, "ref": "refs/pull/1/head"})
	if err != nil || out.(FetchResult).Merge != "" || out.(FetchResult).Trees != nil {
		t.Errorf("no base: %+v %v", out, err)
	}
}