package main

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

func TestCheckPostCSSConfig_BarePlugin(t *testing.T) {
	dir := t.TempDir()
	configPath := filepath.Join(dir, "postcss.config.js")
	if err := os.WriteFile(configPath, []byte(`export default {
  plugins: {
    tailwindcss: {},
    autoprefixer: {},
  },
}
`), 0644); err != nil {
		t.Fatal(err)
	}

	violations := checkPostCSSConfig(dir)
	if len(violations) == 0 {
		t.Fatal("expected violations for bare tailwindcss plugin")
	}

	foundPlugin := false
	for _, v := range violations {
		if v.rule == "postcss-v4-plugin" {
			foundPlugin = true
		}
	}
	if !foundPlugin {
		t.Fatalf("expected postcss-v4-plugin violation, got %v", violations)
	}
}

func TestCheckPostCSSConfig_V4Plugin_OK(t *testing.T) {
	dir := t.TempDir()
	configPath := filepath.Join(dir, "postcss.config.js")
	if err := os.WriteFile(configPath, []byte(`export default {
  plugins: {
    '@tailwindcss/postcss': {},
  },
}
`), 0644); err != nil {
		t.Fatal(err)
	}

	violations := checkPostCSSConfig(dir)
	if len(violations) > 0 {
		t.Fatalf("unexpected violations for v4 postcss config: %v", violations)
	}
}

func TestCheckPostCSSConfig_AutoprefixerWithV4(t *testing.T) {
	dir := t.TempDir()
	configPath := filepath.Join(dir, "postcss.config.js")
	if err := os.WriteFile(configPath, []byte(`export default {
  plugins: {
    '@tailwindcss/postcss': {},
    autoprefixer: {},
  },
}
`), 0644); err != nil {
		t.Fatal(err)
	}

	violations := checkPostCSSConfig(dir)
	foundAutoprefixer := false
	for _, v := range violations {
		if v.rule == "postcss-no-autoprefixer" {
			foundAutoprefixer = true
		}
	}
	if !foundAutoprefixer {
		t.Fatalf("expected postcss-no-autoprefixer violation, got %v", violations)
	}
}

func TestCheckCSSDirectives_V3Syntax(t *testing.T) {
	dir := t.TempDir()
	cssPath := filepath.Join(dir, "index.css")
	if err := os.WriteFile(cssPath, []byte(`@tailwind base;
@tailwind components;
@tailwind utilities;
`), 0644); err != nil {
		t.Fatal(err)
	}

	violations := checkCSSDirectives(dir, dir)
	if len(violations) != 3 {
		t.Fatalf("expected 3 violations for @tailwind directives, got %d: %v", len(violations), violations)
	}
	for _, v := range violations {
		if v.rule != "css-v4-import" {
			t.Fatalf("expected css-v4-import rule, got %s", v.rule)
		}
	}
}

func TestCheckCSSDirectives_V4Syntax_OK(t *testing.T) {
	dir := t.TempDir()
	cssPath := filepath.Join(dir, "index.css")
	if err := os.WriteFile(cssPath, []byte(`@import "tailwindcss";
@config "../tailwind.config.ts";
`), 0644); err != nil {
		t.Fatal(err)
	}

	parentDir := filepath.Dir(dir)
	configPath := filepath.Join(parentDir, "tailwind.config.ts")
	if err := os.WriteFile(configPath, []byte(`export default {}`), 0644); err != nil {
		t.Fatal(err)
	}

	violations := checkCSSDirectives(dir, parentDir)
	if len(violations) > 0 {
		t.Fatalf("unexpected violations for v4 CSS: %v", violations)
	}
}

func TestCheckCSSDirectives_MissingConfig(t *testing.T) {
	dir := t.TempDir()
	srcDir := filepath.Join(dir, "src")
	if err := os.MkdirAll(srcDir, 0755); err != nil {
		t.Fatal(err)
	}

	cssPath := filepath.Join(srcDir, "index.css")
	if err := os.WriteFile(cssPath, []byte(`@import "tailwindcss";
`), 0644); err != nil {
		t.Fatal(err)
	}

	configPath := filepath.Join(dir, "tailwind.config.ts")
	if err := os.WriteFile(configPath, []byte(`export default {}`), 0644); err != nil {
		t.Fatal(err)
	}

	violations := checkCSSDirectives(srcDir, dir)
	foundMissing := false
	for _, v := range violations {
		if v.rule == "css-missing-config" {
			foundMissing = true
		}
	}
	if !foundMissing {
		t.Fatalf("expected css-missing-config violation, got %v", violations)
	}
}

func TestCheckPostCSSConfig_PostCSSRC_JSON(t *testing.T) {
	dir := t.TempDir()
	configPath := filepath.Join(dir, ".postcssrc.json")
	if err := os.WriteFile(configPath, []byte(`{
  "plugins": {
    "tailwindcss": {},
    "autoprefixer": {}
  }
}
`), 0644); err != nil {
		t.Fatal(err)
	}

	violations := checkPostCSSConfig(dir)
	foundPlugin := false
	for _, v := range violations {
		if v.rule == "postcss-v4-plugin" {
			foundPlugin = true
		}
	}
	if !foundPlugin {
		t.Fatalf("expected postcss-v4-plugin violation for .postcssrc.json, got %v", violations)
	}
}

func TestCheckCSSDirectives_PlainCSS_NoViolation(t *testing.T) {
	dir := t.TempDir()
	srcDir := filepath.Join(dir, "src")
	if err := os.MkdirAll(srcDir, 0755); err != nil {
		t.Fatal(err)
	}

	cssPath := filepath.Join(srcDir, "components.css")
	if err := os.WriteFile(cssPath, []byte(`.btn { padding: 8px 16px; }
.card { border: 1px solid #ccc; }
`), 0644); err != nil {
		t.Fatal(err)
	}

	configPath := filepath.Join(dir, "tailwind.config.ts")
	if err := os.WriteFile(configPath, []byte(`export default {}`), 0644); err != nil {
		t.Fatal(err)
	}

	violations := checkCSSDirectives(srcDir, dir)
	if len(violations) > 0 {
		t.Fatalf("plain CSS file should not trigger violations, got %v", violations)
	}
}

func TestCheckCSSDirectives_NodeModulesSkipped(t *testing.T) {
	dir := t.TempDir()
	nmDir := filepath.Join(dir, "node_modules", "some-lib")
	if err := os.MkdirAll(nmDir, 0755); err != nil {
		t.Fatal(err)
	}

	cssPath := filepath.Join(nmDir, "style.css")
	if err := os.WriteFile(cssPath, []byte(`@tailwind base;
@tailwind components;
@tailwind utilities;
`), 0644); err != nil {
		t.Fatal(err)
	}

	violations := checkCSSDirectives(dir, dir)
	if len(violations) > 0 {
		t.Fatalf("node_modules CSS should be skipped, got %v", violations)
	}
}