package render

import (
	"html/template"
	"strings"
	"testing"

	"slidewalk/internal/parser"
)

func TestRender_OrderAndStructure(t *testing.T) {
	page := Page{
		Title: "My Deck",
		Slides: []parser.Slide{
			{Filename: "010-intro.md", Title: "Intro", HTML: template.HTML("<h1>Intro</h1>")},
			{Filename: "020-diagram.md", Class: "center", Notes: "remember the punchline", HTML: template.HTML("<h1>Diagram</h1>")},
			{Filename: "030-outro.md", HTML: template.HTML("<h1>Outro</h1>")},
		},
	}

	var buf strings.Builder
	if err := Render(&buf, page); err != nil {
		t.Fatalf("Render() error = %v", err)
	}
	out := buf.String()

	if !strings.Contains(out, "<title>My Deck</title>") {
		t.Errorf("output missing document title: %s", out)
	}

	idxFirst := strings.Index(out, `data-slide="1"`)
	idxSecond := strings.Index(out, `data-slide="2"`)
	idxThird := strings.Index(out, `data-slide="3"`)
	if idxFirst == -1 || idxSecond == -1 || idxThird == -1 {
		t.Fatalf("output missing expected data-slide attributes: %s", out)
	}
	if !(idxFirst < idxSecond && idxSecond < idxThird) {
		t.Errorf("slides not in presentation order: %s", out)
	}

	if !strings.Contains(out, `class="slide center"`) {
		t.Errorf("output missing merged slide+custom class: %s", out)
	}
	if !strings.Contains(out, `<div class="notes">remember the punchline</div>`) {
		t.Errorf("output missing rendered notes: %s", out)
	}

	if strings.Count(out, "<h1>Intro</h1>") != 1 ||
		strings.Count(out, "<h1>Diagram</h1>") != 1 ||
		strings.Count(out, "<h1>Outro</h1>") != 1 {
		t.Errorf("output missing one or more slide bodies: %s", out)
	}

	if !strings.Contains(out, `<link rel="stylesheet" href="vendor/style.css">`) {
		t.Errorf("output missing stylesheet link: %s", out)
	}
	if !strings.Contains(out, "mermaid.initialize") {
		t.Errorf("output missing mermaid.initialize call: %s", out)
	}
	if !strings.Contains(out, `<script src="vendor/nav.js">`) {
		t.Errorf("output missing nav.js script tag: %s", out)
	}
}

func TestRender_IncrementalSlideGetsDataAttribute(t *testing.T) {
	page := Page{
		Slides: []parser.Slide{
			{Filename: "010-intro.md", Incremental: true, HTML: template.HTML("<ul><li>A</li></ul>")},
			{Filename: "020-outro.md", HTML: template.HTML("<h1>Outro</h1>")},
		},
	}

	var buf strings.Builder
	if err := Render(&buf, page); err != nil {
		t.Fatalf("Render() error = %v", err)
	}
	out := buf.String()

	if !strings.Contains(out, `data-slide="1" data-incremental="true"`) {
		t.Errorf("output missing data-incremental attribute on incremental slide: %s", out)
	}
	if strings.Contains(out, `data-slide="2" data-incremental`) {
		t.Errorf("non-incremental slide should not get data-incremental attribute: %s", out)
	}
}

func TestRender_NoNotesOmitsNotesElement(t *testing.T) {
	page := Page{
		Slides: []parser.Slide{
			{Filename: "010-intro.md", HTML: template.HTML("<h1>Intro</h1>")},
		},
	}

	var buf strings.Builder
	if err := Render(&buf, page); err != nil {
		t.Fatalf("Render() error = %v", err)
	}

	if strings.Contains(buf.String(), `class="notes"`) {
		t.Errorf("output should omit notes element when Notes is empty: %s", buf.String())
	}
}

func TestRender_DevReloadScript(t *testing.T) {
	tests := []struct {
		name      string
		devReload bool
	}{
		{name: "omitted for static export", devReload: false},
		{name: "included for dev server", devReload: true},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			page := Page{
				Slides: []parser.Slide{
					{Filename: "010-intro.md", HTML: template.HTML("<h1>Intro</h1>")},
				},
				DevReload: tt.devReload,
			}

			var buf strings.Builder
			if err := Render(&buf, page); err != nil {
				t.Fatalf("Render() error = %v", err)
			}

			got := strings.Contains(buf.String(), `<script src="vendor/live-reload.js">`)
			if got != tt.devReload {
				t.Errorf("live-reload script present = %v, want %v", got, tt.devReload)
			}
		})
	}
}