package template

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

func TestNewCache(t *testing.T) {
	cache := NewCache("")
	if cache == nil {
		t.Fatal("NewCache returned nil")
	}
	if cache.templates == nil {
		t.Fatal("templates map not initialized")
	}
}

func TestPositionalReplacement(t *testing.T) {
	tmpl := &Template{
		name:    "test",
		content: "Hello {0}, you are {1} years old!",
	}

	result := tmpl.RenderPositional("Alice", 25)
	expected := "Hello Alice, you are 25 years old!"

	if result != expected {
		t.Errorf("Expected %q, got %q", expected, result)
	}
}

func TestNamedReplacement(t *testing.T) {
	tmpl := &Template{
		name:    "test",
		content: "Hello {name}, you are {age} years old!",
	}

	data := map[string]any{
		"name": "Bob",
		"age":  30,
	}

	result := tmpl.RenderNamed(data)
	expected := "Hello Bob, you are 30 years old!"

	if result != expected {
		t.Errorf("Expected %q, got %q", expected, result)
	}
}

func TestDotNotationReplacement(t *testing.T) {
	tmpl := &Template{
		name:    "test",
		content: "User: {user.name}, Email: {user.contact.email}",
	}

	data := map[string]any{
		"user": map[string]any{
			"name": "Charlie",
			"contact": map[string]any{
				"email": "charlie@example.com",
			},
		},
	}

	result := tmpl.RenderNamed(data)
	expected := "User: Charlie, Email: charlie@example.com"

	if result != expected {
		t.Errorf("Expected %q, got %q", expected, result)
	}
}

func TestTemplateLoadingAndCaching(t *testing.T) {
	tmpDir, err := os.MkdirTemp("", "template_test")
	if err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(tmpDir)

	templatesDir := filepath.Join(tmpDir, "templates")
	err = os.MkdirAll(templatesDir, 0755)
	if err != nil {
		t.Fatal(err)
	}

	templateFile := filepath.Join(templatesDir, "test.html")
	content := "Hello {name}!"
	err = os.WriteFile(templateFile, []byte(content), 0644)
	if err != nil {
		t.Fatal(err)
	}

	cache := NewCache(tmpDir)

	tmpl, err := cache.Load("test.html")
	if err != nil {
		t.Fatal(err)
	}

	if tmpl.content != content {
		t.Errorf("Expected content %q, got %q", content, tmpl.content)
	}

	tmpl2, err := cache.Load("test.html")
	if err != nil {
		t.Fatal(err)
	}

	if tmpl != tmpl2 {
		t.Error("Template should be cached and return same instance")
	}
}

func TestTemplateReloading(t *testing.T) {
	tmpDir, err := os.MkdirTemp("", "template_test")
	if err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(tmpDir)

	templatesDir := filepath.Join(tmpDir, "templates")
	err = os.MkdirAll(templatesDir, 0755)
	if err != nil {
		t.Fatal(err)
	}

	templateFile := filepath.Join(templatesDir, "test.html")
	content1 := "Hello {name}!"
	err = os.WriteFile(templateFile, []byte(content1), 0644)
	if err != nil {
		t.Fatal(err)
	}

	cache := NewCache(tmpDir)

	tmpl, err := cache.Load("test.html")
	if err != nil {
		t.Fatal(err)
	}

	if tmpl.content != content1 {
		t.Errorf("Expected content %q, got %q", content1, tmpl.content)
	}

	time.Sleep(10 * time.Millisecond)

	content2 := "Hi {name}, welcome!"
	err = os.WriteFile(templateFile, []byte(content2), 0644)
	if err != nil {
		t.Fatal(err)
	}

	tmpl2, err := cache.Load("test.html")
	if err != nil {
		t.Fatal(err)
	}

	if tmpl2.content != content2 {
		t.Errorf("Expected reloaded content %q, got %q", content2, tmpl2.content)
	}
}

func TestGetNestedValue(t *testing.T) {
	tmpl := &Template{}

	data := map[string]any{
		"level1": map[string]any{
			"level2": map[string]any{
				"value": "found",
			},
		},
	}

	result := tmpl.getNestedValue(data, "level1.level2.value")
	if result != "found" {
		t.Errorf("Expected 'found', got %v", result)
	}

	result = tmpl.getNestedValue(data, "level1.nonexistent")
	if result != nil {
		t.Errorf("Expected nil for nonexistent path, got %v", result)
	}
}

func TestMixedReplacementTypes(t *testing.T) {
	tmpl := &Template{
		name:    "test",
		content: "Hello {name}, you have {count} {items.type}s!",
	}

	data := map[string]any{
		"name":  "Dave",
		"count": 5,
		"items": map[string]any{
			"type": "apple",
		},
	}

	result := tmpl.RenderNamed(data)
	expected := "Hello Dave, you have 5 apples!"

	if result != expected {
		t.Errorf("Expected %q, got %q", expected, result)
	}
}

func TestIncludeSupport(t *testing.T) {
	tmpDir, err := os.MkdirTemp("", "template_test")
	if err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(tmpDir)

	templatesDir := filepath.Join(tmpDir, "templates")
	err = os.MkdirAll(templatesDir, 0755)
	if err != nil {
		t.Fatal(err)
	}

	// Create main template with include
	mainTemplate := `<html><head>{include "header.html"}</head><body>Hello {name}!</body></html>`
	err = os.WriteFile(filepath.Join(templatesDir, "main.html"), []byte(mainTemplate), 0644)
	if err != nil {
		t.Fatal(err)
	}

	// Create included template
	headerTemplate := `<title>{title}</title><meta charset="utf-8">`
	err = os.WriteFile(filepath.Join(templatesDir, "header.html"), []byte(headerTemplate), 0644)
	if err != nil {
		t.Fatal(err)
	}

	cache := NewCache(tmpDir)
	tmpl, err := cache.Load("main.html")
	if err != nil {
		t.Fatal(err)
	}

	data := map[string]any{
		"name":  "Alice",
		"title": "Welcome",
	}

	result := tmpl.RenderNamed(data)
	expected := "<html><head><title>Welcome</title><meta charset=\"utf-8\"></head><body>Hello Alice!</body></html>"

	if result != expected {
		t.Errorf("Expected %q, got %q", expected, result)
	}
}

func TestBlocksAndYield(t *testing.T) {
	tmpl := &Template{
		name:    "test",
		content: `{block "content"}Default content{/block}<main>{yield content}</main>`,
	}

	result := tmpl.RenderNamed(map[string]any{})
	expected := "<main>Default content</main>"

	if result != expected {
		t.Errorf("Expected %q, got %q", expected, result)
	}
}

func TestTemplateInheritance(t *testing.T) {
	tmpDir, err := os.MkdirTemp("", "template_test")
	if err != nil {
		t.Fatal(err)
	}
	defer os.RemoveAll(tmpDir)

	templatesDir := filepath.Join(tmpDir, "templates")
	err = os.MkdirAll(templatesDir, 0755)
	if err != nil {
		t.Fatal(err)
	}

	// Layout template
	layoutTemplate := `<!DOCTYPE html><html><head><title>{title}</title></head><body>{yield content}</body></html>`
	err = os.WriteFile(filepath.Join(templatesDir, "layout.html"), []byte(layoutTemplate), 0644)
	if err != nil {
		t.Fatal(err)
	}

	// Page template that extends layout
	pageTemplate := `{include "layout.html"}{block "content"}<h1>Welcome {name}!</h1><p>This is the content block.</p>{/block}`
	err = os.WriteFile(filepath.Join(templatesDir, "page.html"), []byte(pageTemplate), 0644)
	if err != nil {
		t.Fatal(err)
	}

	cache := NewCache(tmpDir)
	tmpl, err := cache.Load("page.html")
	if err != nil {
		t.Fatal(err)
	}

	data := map[string]any{
		"title": "Test Page",
		"name":  "Bob",
	}

	result := tmpl.RenderNamed(data)
	expected := `<!DOCTYPE html><html><head><title>Test Page</title></head><body><h1>Welcome Bob!</h1><p>This is the content block.</p></body></html>`

	if result != expected {
		t.Errorf("Expected %q, got %q", expected, result)
	}
}