package main

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

// buildWithView builds a two-photo site with the given default view and returns
// the output dir.
func buildWithView(t *testing.T, view string) string {
	t.Helper()
	content := t.TempDir()
	output := t.TempDir()
	writePNG(t, filepath.Join(content, "a.png"))
	writePNG(t, filepath.Join(content, "b.png"))

	g := NewGenerator(content, output, "http://x", "A", "@a", "bio", "", "f", "s", "m", 60, view)
	if err := g.Build(); err != nil {
		t.Fatalf("build (%s): %v", view, err)
	}
	return output
}

func exists(p string) bool { _, err := os.Stat(p); return err == nil }

func TestDefaultViewTimeline(t *testing.T) {
	out := buildWithView(t, viewTimeline)

	// Timeline owns the root; grid is the secondary under /grid/.
	if !exists(filepath.Join(out, "index.html")) {
		t.Error("root index.html missing")
	}
	if !exists(filepath.Join(out, "grid", "index.html")) {
		t.Error("/grid/ should exist as the secondary view")
	}
	// No /timeline/ dir — timeline is at the root, not under its own name.
	if exists(filepath.Join(out, "timeline")) {
		t.Error("/timeline/ should not exist when timeline is the default")
	}

	// The root (timeline) links to grid at /grid/.
	root := readFile(t, filepath.Join(out, "index.html"))
	if !strings.Contains(root, `href="/grid/"`) {
		t.Error("timeline root should link to /grid/")
	}
}

func TestDefaultViewGrid(t *testing.T) {
	out := buildWithView(t, viewGrid)

	// Grid owns the root; timeline is the secondary under /timeline/.
	if !exists(filepath.Join(out, "index.html")) {
		t.Error("root index.html missing")
	}
	if !exists(filepath.Join(out, "timeline", "index.html")) {
		t.Error("/timeline/ should exist as the secondary view")
	}
	// No /grid/ dir — grid is at the root now.
	if exists(filepath.Join(out, "grid")) {
		t.Error("/grid/ should not exist when grid is the default")
	}

	// The root (grid) links back to the timeline at /timeline/.
	root := readFile(t, filepath.Join(out, "index.html"))
	if !strings.Contains(root, `href="/timeline/"`) {
		t.Error("grid root should link to /timeline/")
	}
}

// TestDefaultViewSwitchCleansUp confirms that flipping the default view does not
// leave the previous root's view directory behind.
func TestDefaultViewSwitchCleansUp(t *testing.T) {
	content := t.TempDir()
	output := t.TempDir()
	writePNG(t, filepath.Join(content, "a.png"))

	// First build with grid as root → creates /timeline/.
	g1 := NewGenerator(content, output, "http://x", "A", "@a", "b", "", "f", "s", "m", 60, viewGrid)
	if err := g1.Build(); err != nil {
		t.Fatal(err)
	}
	if !exists(filepath.Join(output, "timeline")) {
		t.Fatal("expected /timeline/ after grid-default build")
	}

	// Rebuild with timeline as root → /timeline/ must be gone, /grid/ present.
	g2 := NewGenerator(content, output, "http://x", "A", "@a", "b", "", "f", "s", "m", 60, viewTimeline)
	if err := g2.Build(); err != nil {
		t.Fatal(err)
	}
	if exists(filepath.Join(output, "timeline")) {
		t.Error("/timeline/ left over after switching default to timeline")
	}
	if !exists(filepath.Join(output, "grid", "index.html")) {
		t.Error("/grid/ should exist after switching default to timeline")
	}
}

func readFile(t *testing.T, p string) string {
	t.Helper()
	b, err := os.ReadFile(p)
	if err != nil {
		t.Fatal(err)
	}
	return string(b)
}