package codegen

import (
	"strings"
	"testing"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func TestGenerateClass_Good(t *testing.T) {
	js, err := GenerateClass("photo-grid", "C")
	require.NoError(t, err)
	assert.Contains(t, js, "class PhotoGrid extends HTMLElement")
	assert.Contains(t, js, "attachShadow")
	assert.Contains(t, js, `mode: "closed"`)
	assert.Contains(t, js, "photo-grid")
}

func TestGenerateClass_Bad_InvalidTag(t *testing.T) {
	_, err := GenerateClass("invalid", "C")
	assert.Error(t, err, "custom element names must contain a hyphen")

	_, err = GenerateClass("Nav-Bar", "C")
	assert.Error(t, err, "custom element names must be lowercase")

	_, err = GenerateClass("nav bar", "C")
	assert.Error(t, err, "custom element names must reject spaces")
}

func TestGenerateRegistration_Good(t *testing.T) {
	js := GenerateRegistration("photo-grid", "PhotoGrid")
	assert.Contains(t, js, "customElements.define")
	assert.Contains(t, js, `"photo-grid"`)
	assert.Contains(t, js, "PhotoGrid")
}

func TestTagToClassName_Good(t *testing.T) {
	tests := []struct{ tag, want string }{
		{"photo-grid", "PhotoGrid"},
		{"nav-breadcrumb", "NavBreadcrumb"},
		{"my-super-widget", "MySuperWidget"},
	}
	for _, tt := range tests {
		got := TagToClassName(tt.tag)
		assert.Equal(t, tt.want, got, "TagToClassName(%q)", tt.tag)
	}
}

func TestGenerateBundle_Good(t *testing.T) {
	slots := map[string]string{
		"C": "main-content",
		"H": "nav-bar",
		"F": "page-footer",
	}
	js, err := GenerateBundle(slots)
	require.NoError(t, err)
	assert.Contains(t, js, "NavBar")
	assert.Contains(t, js, "MainContent")
	assert.Contains(t, js, "PageFooter")
	assert.Equal(t, 3, strings.Count(js, "extends HTMLElement"))

	h := strings.Index(js, "NavBar")
	c := strings.Index(js, "MainContent")
	f := strings.Index(js, "PageFooter")
	assert.True(t, h >= 0 && c >= 0 && f >= 0, "expected all generated classes in output")
	assert.True(t, h < c && c < f, "expected canonical HLCRF order in generated bundle")
}

func TestGenerateBundle_DeduplicatesTags(t *testing.T) {
	slots := map[string]string{
		"H": "nav-bar",
		"C": "nav-bar",
		"F": "page-footer",
	}

	js, err := GenerateBundle(slots)
	require.NoError(t, err)

	assert.Equal(t, 2, strings.Count(js, "extends HTMLElement"))
	assert.Equal(t, 1, strings.Count(js, "class NavBar extends HTMLElement"))
	assert.Equal(t, 1, strings.Count(js, "class PageFooter extends HTMLElement"))
}

func TestGenerateBundle_Bad_InvalidSlotKey(t *testing.T) {
	slots := map[string]string{
		"H": "nav-bar",
		"X": "custom-widget",
	}

	_, err := GenerateBundle(slots)
	require.Error(t, err)
	assert.Contains(t, err.Error(), "invalid slot key")
	assert.Contains(t, err.Error(), `"X"`)
}

func TestGenerateTypeDefinitions_Good(t *testing.T) {
	slots := map[string]string{
		"H": "nav-bar",
		"C": "main-content",
	}

	dts, err := GenerateTypeDefinitions(slots)
	require.NoError(t, err)
	assert.Contains(t, dts, "declare global")
	assert.Contains(t, dts, "interface WcReadyDetail")
	assert.Contains(t, dts, `interface HTMLElementEventMap`)
	assert.Contains(t, dts, `"wc-ready": CustomEvent<WcReadyDetail>;`)
	assert.Contains(t, dts, "export declare class NavBar extends HTMLElement")
	assert.Contains(t, dts, "export declare class MainContent extends HTMLElement")
	assert.Contains(t, dts, `"nav-bar": NavBar;`)
	assert.Contains(t, dts, `"main-content": MainContent;`)
	assert.Contains(t, dts, "export {};")
}

func TestGenerateTypeDefinitions_DeduplicatesTags(t *testing.T) {
	slots := map[string]string{
		"H": "nav-bar",
		"C": "nav-bar",
		"F": "page-footer",
	}

	dts, err := GenerateTypeDefinitions(slots)
	require.NoError(t, err)

	assert.Equal(t, 2, strings.Count(dts, "extends HTMLElement"))
	assert.Equal(t, 1, strings.Count(dts, `"nav-bar": NavBar;`))
	assert.Equal(t, 1, strings.Count(dts, `"page-footer": PageFooter;`))
}

func TestGenerateTypeDefinitions_SkipsInvalidTags(t *testing.T) {
	slots := map[string]string{
		"H": "nav-bar",
		"C": "Nav-Bar",
		"F": "nav bar",
	}

	dts, err := GenerateTypeDefinitions(slots)
	require.NoError(t, err)

	assert.Contains(t, dts, `"nav-bar": NavBar;`)
	assert.NotContains(t, dts, "Nav-Bar")
	assert.NotContains(t, dts, "nav bar")
	assert.Equal(t, 1, strings.Count(dts, "extends HTMLElement"))
}