package comics

import (
	"archive/zip"
	"os"
	"path/filepath"
	"testing"
)

func writeCBZ(t *testing.T, entries map[string]string) string {
	t.Helper()
	p := filepath.Join(t.TempDir(), "test.cbz")
	f, err := os.Create(p)
	if err != nil {
		t.Fatal(err)
	}
	defer f.Close()

	zw := zip.NewWriter(f)
	for name, body := range entries {
		w, err := zw.Create(name)
		if err != nil {
			t.Fatal(err)
		}
		if _, err := w.Write([]byte(body)); err != nil {
			t.Fatal(err)
		}
	}
	if err := zw.Close(); err != nil {
		t.Fatal(err)
	}
	return p
}

func TestListPagesNaturalOrder(t *testing.T) {
	p := writeCBZ(t, map[string]string{
		"page10.jpg":           "ten",
		"page2.jpg":            "two",
		"page1.jpg":            "one",
		"notes.txt":            "not an image",
		"__MACOSX/._page1.jpg": "junk",
	})

	pages, err := ListPages(p)
	if err != nil {
		t.Fatalf("ListPages: %v", err)
	}
	want := []string{"page1.jpg", "page2.jpg", "page10.jpg"}
	if len(pages) != len(want) {
		t.Fatalf("got %d pages, want %d: %+v", len(pages), len(want), pages)
	}
	for i, name := range want {
		if pages[i].Name != name {
			t.Errorf("page %d = %q, want %q", i+1, pages[i].Name, name)
		}
		if pages[i].Index != i+1 {
			t.Errorf("page %d index = %d, want %d", i, pages[i].Index, i+1)
		}
	}
}

func TestReadPage(t *testing.T) {
	p := writeCBZ(t, map[string]string{"page1.jpg": "hello-page"})

	data, err := ReadPage(p, "page1.jpg")
	if err != nil {
		t.Fatalf("ReadPage: %v", err)
	}
	if string(data) != "hello-page" {
		t.Errorf("page content = %q", data)
	}

	if _, err := ReadPage(p, "missing.jpg"); err == nil {
		t.Error("ReadPage succeeded for a missing entry")
	}
}

func TestListPagesRejectsArchiveWithoutImages(t *testing.T) {
	p := writeCBZ(t, map[string]string{"readme.txt": "nothing to see"})
	if _, err := ListPages(p); err == nil {
		t.Error("ListPages succeeded on an archive with no images")
	}
}

func TestNaturalLess(t *testing.T) {
	cases := []struct {
		a, b string
		want bool
	}{
		{"page1.jpg", "page2.jpg", true},
		{"page2.jpg", "page10.jpg", true},
		{"page10.jpg", "page2.jpg", false},
		{"page01.jpg", "page1.jpg", false}, // equal numerically
		{"page1.jpg", "page01.jpg", false},
		{"a.jpg", "b.jpg", true},
	}
	for _, c := range cases {
		if got := naturalLess(c.a, c.b); got != c.want {
			t.Errorf("naturalLess(%q, %q) = %v, want %v", c.a, c.b, got, c.want)
		}
	}
}