package tempdir

import (
	"errors"
	"os"
	"path/filepath"
	"runtime"
	"strings"
	"testing"
)

func TestOutsideRemovesAllocatedPathWhenResolutionFails(t *testing.T) {
	for _, fallback := range []bool{false, true} {
		for _, operation := range []string{"absolute", "symlinks"} {
			name := operation
			if fallback {
				name += "-fallback"
			}
			t.Run(name, func(t *testing.T) {
				parent := t.TempDir()
				repository := filepath.Join(parent, "repository")
				local := filepath.Join(repository, "tmp")
				if err := os.MkdirAll(local, 0o700); err != nil {
					t.Fatal(err)
				}
				if fallback {
					setTemporaryDirectory(t, local)
				} else {
					setTemporaryDirectory(t, parent)
				}
				resolutionErr := errors.New("resolution failed")
				removalErr := errors.New("removal failed")
				calls := 0
				failed := false
				var removed string
				failAt := 2
				if fallback {
					failAt = 3
				}
				abs := func(path string) (string, error) {
					if operation == "absolute" {
						calls++
						if calls == failAt {
							failed = true
							return "", resolutionErr
						}
					}
					return filepath.Abs(path)
				}
				resolve := func(path string) (string, error) {
					if operation == "symlinks" {
						calls++
						if calls == failAt {
							failed = true
							return "", resolutionErr
						}
					}
					return filepath.EvalSymlinks(path)
				}
				remove := func(path string) error {
					if err := os.RemoveAll(path); err != nil {
						return err
					}
					if failed {
						removed = path
						return removalErr
					}
					return nil
				}
				_, err := outside(repository, "owned-", abs, resolve, remove)
				if !errors.Is(err, resolutionErr) || !errors.Is(err, removalErr) || removed == "" || !strings.Contains(err.Error(), removed) || !strings.HasPrefix(filepath.Base(removed), "owned-") {
					t.Fatalf("error = %v, removed = %q", err, removed)
				}
			})
		}
	}
}

func TestOutsideHonorsRelativeTemporaryDirectory(t *testing.T) {
	parent := t.TempDir()
	repository := t.TempDir()
	cwd, err := os.Getwd()
	if err != nil {
		t.Fatal(err)
	}
	relative, err := filepath.Rel(cwd, parent)
	if err != nil {
		t.Skip("temporary directory is on another volume")
	}
	setTemporaryDirectory(t, relative)
	directory, err := Outside(repository, "fixture-")
	if err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(directory)
	if !filepath.IsAbs(directory) || filepath.Dir(directory) != parent {
		t.Fatalf("temporary storage=%q want parent %q", directory, parent)
	}
}

func TestOutsideFallsBackWhenTemporaryDirectoryIsInsideWorktree(t *testing.T) {
	parent := t.TempDir()
	repository := filepath.Join(parent, "worktree")
	if err := os.Mkdir(repository, 0o700); err != nil {
		t.Fatal(err)
	}
	localTemporary := filepath.Join(repository, "tmp")
	if err := os.Mkdir(localTemporary, 0o700); err != nil {
		t.Fatal(err)
	}
	setTemporaryDirectory(t, localTemporary)
	directory, err := Outside(repository, "fixture-")
	if err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(directory)
	if filepath.Dir(directory) != parent {
		t.Fatalf("temporary storage=%q want external parent %q", directory, parent)
	}
	remaining, err := os.ReadDir(repository)
	if err != nil || len(remaining) != 1 || remaining[0].Name() != "tmp" {
		t.Fatalf("temporary storage left behind in worktree: %v %v", remaining, err)
	}
}

func setTemporaryDirectory(t *testing.T, directory string) {
	t.Helper()
	variable := "TMPDIR"
	if runtime.GOOS == "windows" {
		variable = "TMP"
	}
	t.Setenv(variable, directory)
}