package main

import (
	"errors"
	"os"
	"path/filepath"
	"reflect"
	"strconv"
	"strings"
	"testing"
)

const nobody = 4194400

func TestTheDeclaredWallpaperIsReadFromTheModulesFehbg(t *testing.T) {
	raw, err := os.ReadFile(filepath.Join("..", "..", "files", "fehbg"))
	if err != nil {
		t.Fatal(err)
	}
	w := parseFehbg(string(raw), "/home/op")
	if w == nil || w.Mode != "fill" || !reflect.DeepEqual(w.Images, []string{"/home/op/.local/share/feh/wallpapers/default.jpg"}) {
		t.Fatalf("%+v", w)
	}
	// The form feh writes itself, single-quoted, two monitors.
	w = parseFehbg("#!/bin/sh\nfeh --no-fehbg --bg-center '/a b/one.png' '/two.png' \n", "/home/op")
	if w.Mode != "center" || !reflect.DeepEqual(w.Images, []string{"/a b/one.png", "/two.png"}) {
		t.Fatalf("%+v", w)
	}
	if parseFehbg("#!/bin/sh\n", "/h") != nil {
		t.Fatal("a file without feh declares a wallpaper")
	}
}

func TestSetPutsTheImagesUpForThisSessionAndCurrentSaysSo(t *testing.T) {
	root := fakeMachine(t)
	fakeProcess(t, nobody, "i3", "DISPLAY=:1")
	if err := os.MkdirAll(filepath.Join(runUserDir, strconv.Itoa(os.Getuid())), 0o700); err != nil {
		t.Fatal(err)
	}
	home := filepath.Join(root, "home")
	for _, f := range []string{"Pictures/a.jpg", "Pictures/b.jpg"} {
		if err := os.MkdirAll(filepath.Dir(filepath.Join(home, f)), 0o755); err != nil {
			t.Fatal(err)
		}
		if err := os.WriteFile(filepath.Join(home, f), []byte("jpg"), 0o644); err != nil {
			t.Fatal(err)
		}
	}
	src, _ := os.ReadFile(filepath.Join("..", "..", "files", "fehbg"))
	if err := os.WriteFile(filepath.Join(home, ".fehbg"), src, 0o755); err != nil {
		t.Fatal(err)
	}
	bin := fakeBinaries(t, map[string]string{"feh": `echo "$* DISPLAY=$DISPLAY" > "$LOG"`})
	t.Setenv("LOG", filepath.Join(bin, "log"))
	got, err := Set([]string{"~/Pictures/a.jpg", "Pictures/b.jpg"}, "scale")
	if err != nil || !strings.Contains(got.Note, "next login") {
		t.Fatalf("%+v, %v", got, err)
	}
	asked, _ := os.ReadFile(filepath.Join(bin, "log"))
	want := "--no-fehbg --bg-scale " + filepath.Join(home, "Pictures/a.jpg") + " " + filepath.Join(home, "Pictures/b.jpg") + " DISPLAY=:1\n"
	if string(asked) != want {
		t.Fatalf("feh was asked %q, want %q", asked, want)
	}
	cur, err := Current()
	if err != nil || cur.Declared == nil || cur.Session == nil || cur.Session.Mode != "scale" || len(cur.Session.Images) != 2 ||
		cur.Declared.Images[0] != filepath.Join(home, ".local/share/feh/wallpapers/default.jpg") {
		t.Fatalf("%+v, %v", cur, err)
	}
}

func TestSetRefusesWhatFehCannotShow(t *testing.T) {
	fakeMachine(t)
	if _, err := Set([]string{"/nowhere.jpg"}, ""); err == nil {
		t.Fatal("a missing image was accepted")
	}
	if _, err := Set([]string{"/"}, ""); err == nil {
		t.Fatal("a directory was accepted")
	}
	if _, err := Set([]string{"/etc/hostname"}, "stretch"); err == nil {
		t.Fatal("an unknown mode was accepted")
	}
	if _, err := Set(nil, ""); err == nil {
		t.Fatal("no image was accepted")
	}
	f := filepath.Join(t.TempDir(), "x.jpg")
	if err := os.WriteFile(f, nil, 0o644); err != nil {
		t.Fatal(err)
	}
	if _, err := Set([]string{f}, ""); !errors.Is(err, ErrNoSession) {
		t.Fatalf("without a session: %v", err)
	}
}