package app

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

	"codeberg.org/turbo-editors/turbo-core/profile"
)

// touch creates an empty file, making its directory first.
func touch(t *testing.T, path string) {
	t.Helper()
	if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
		t.Fatalf("creating %s: %v", filepath.Dir(path), err)
	}
	if err := os.WriteFile(path, nil, 0o644); err != nil {
		t.Fatalf("writing %s: %v", path, err)
	}
}

func TestProjectRootWalksUpToTheMarker(t *testing.T) {
	root := t.TempDir()
	touch(t, filepath.Join(root, "go.mod"))
	deep := filepath.Join(root, "internal", "app", "app.go")
	touch(t, deep)

	got := ProjectRoot(profile.Profile{RootMarkers: []string{"go.mod"}}, []string{deep})

	if got != root {
		t.Errorf("ProjectRoot() = %q, want %q", got, root)
	}
}

func TestProjectRootTakesTheFirstMarkerItMeetsGoingUp(t *testing.T) {
	// A nested module is its own project; walking past it to the outer one
	// would hand the language server a workspace the file is not in.
	outer := t.TempDir()
	touch(t, filepath.Join(outer, "Cargo.toml"))
	inner := filepath.Join(outer, "crates", "parser")
	touch(t, filepath.Join(inner, "Cargo.toml"))
	file := filepath.Join(inner, "src", "lib.rs")
	touch(t, file)

	got := ProjectRoot(profile.Profile{RootMarkers: []string{"Cargo.toml"}}, []string{file})

	if got != inner {
		t.Errorf("ProjectRoot() = %q, want the nearest root %q", got, inner)
	}
}

func TestProjectRootAcceptsAnyOfTheMarkers(t *testing.T) {
	root := t.TempDir()
	touch(t, filepath.Join(root, "Cargo.toml"))
	file := filepath.Join(root, "src", "main.rs")
	touch(t, file)

	got := ProjectRoot(profile.Profile{RootMarkers: []string{"rust-toolchain.toml", "Cargo.toml"}}, []string{file})

	if got != root {
		t.Errorf("ProjectRoot() = %q, want %q", got, root)
	}
}

func TestProjectRootFallsBackToTheFilesOwnDirectory(t *testing.T) {
	// A file outside any project still has to give the server somewhere; the
	// filesystem root would be absurd.
	dir := t.TempDir()
	file := filepath.Join(dir, "scratch.go")
	touch(t, file)

	got := ProjectRoot(profile.Profile{RootMarkers: []string{"no-such-marker-file"}}, []string{file})

	if got != dir {
		t.Errorf("ProjectRoot() = %q, want %q", got, dir)
	}
}

func TestProjectRootWithNoFilesUsesTheWorkingDirectory(t *testing.T) {
	dir := t.TempDir()
	touch(t, filepath.Join(dir, "go.mod"))
	t.Chdir(dir)

	got := ProjectRoot(profile.Profile{RootMarkers: []string{"go.mod"}}, nil)

	// The temporary directory may be reached through a symlink, so the
	// comparison is on what the two resolve to.
	if resolve(t, got) != resolve(t, dir) {
		t.Errorf("ProjectRoot() = %q, want %q", got, dir)
	}
}

func TestAProfileWithNoMarkersDoesNotWalk(t *testing.T) {
	// An editor for a language with no project file at all: the directory the
	// file is in is the best answer available.
	dir := t.TempDir()
	file := filepath.Join(dir, "notes.txt")
	touch(t, file)

	got := ProjectRoot(profile.Profile{}, []string{file})

	if got != dir {
		t.Errorf("ProjectRoot() = %q, want %q", got, dir)
	}
}

// resolve follows symlinks, which is what /tmp is on some systems.
func resolve(t *testing.T, path string) string {
	t.Helper()
	resolved, err := filepath.EvalSymlinks(path)
	if err != nil {
		return path
	}
	return resolved
}