package main

import (
	"os"
	"path/filepath"
	"strings"
	"testing"
	"time"
)

var when = time.Date(2026, 8, 27, 12, 0, 0, 0, time.UTC)

// A directory gets a generated name: writing into ~/photos/weather is more
// useful than refusing, and two days do not overwrite each other.
func TestResolveOutIntoADirectory(t *testing.T) {
	dir := t.TempDir()
	got, err := resolveOut(dir, "Krakow, PL", when, "svg")
	if err != nil {
		t.Fatal(err)
	}
	want := filepath.Join(dir, "krakow-pl-2026-08-27.svg")
	if got != want {
		t.Fatalf("got %q, want %q", got, want)
	}

	// A different day must not collide with the first.
	other, _ := resolveOut(dir, "Krakow, PL", when.AddDate(0, 0, 1), "svg")
	if other == got {
		t.Error("two days produced the same filename")
	}
}

func TestResolveOutCreatesATrailingSlashDirectory(t *testing.T) {
	dir := filepath.Join(t.TempDir(), "photos", "weather") + string(os.PathSeparator)
	got, err := resolveOut(dir, "Krakow, PL", when, "svg")
	if err != nil {
		t.Fatal(err)
	}
	if fi, err := os.Stat(filepath.Dir(got)); err != nil || !fi.IsDir() {
		t.Fatalf("directory was not created: %v", err)
	}
}

// "-o weather" should not produce an extensionless file no viewer will open.
func TestResolveOutAddsTheExtensionToABareName(t *testing.T) {
	base := filepath.Join(t.TempDir(), "weather")
	got, err := resolveOut(base, "Krakow, PL", when, "svg")
	if err != nil {
		t.Fatal(err)
	}
	if !strings.HasSuffix(got, ".svg") {
		t.Fatalf("got %q, want a .svg suffix", got)
	}
}

// An explicit extension is respected, whatever the format's default.
func TestResolveOutKeepsAnExplicitExtension(t *testing.T) {
	base := filepath.Join(t.TempDir(), "chart.png")
	got, _ := resolveOut(base, "Krakow, PL", when, "svg")
	if got != base {
		t.Fatalf("got %q, want %q unchanged", got, base)
	}
}

func TestSlug(t *testing.T) {
	for in, want := range map[string]string{
		"Krakow, PL":       "krakow-pl",
		"Tarnów, PL":       "tarnow-pl",
		"Zbylitowska Góra": "zbylitowska-gora",
		"Gdańsk":           "gdansk",
		"Łódź":             "lodz",
		"  spaced  out  ":  "spaced-out",
		"50.0617,19.9373":  "50-0617-19-9373",
		"!!!":              "",
	} {
		if got := slug(in); got != want {
			t.Errorf("slug(%q) = %q, want %q", in, got, want)
		}
	}
}

// A slug must never contain a path separator, or -o would write outside the
// directory it was given.
func TestSlugCannotEscapeADirectory(t *testing.T) {
	for _, nasty := range []string{"../../etc/passwd", "a/b", `c\d`} {
		got := slug(nasty)
		if strings.ContainsAny(got, `/\`) || strings.Contains(got, "..") {
			t.Errorf("slug(%q) = %q, which can escape the directory", nasty, got)
		}
	}
}