package main

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

// minimalValidPreset returns a presets.json that satisfies the strict decoder
// (all known fields, correct types, required id+name).
const minimalValidPresetJSON = `[
  {
    "id": "test-preset",
    "name": "Test Preset",
    "description": "A minimal test preset",
    "theme": {
      "lightColors": {
        "background": "0 0% 100%",
        "foreground": "240 10% 3.9%",
        "card": "0 0% 100%",
        "cardForeground": "240 10% 3.9%",
        "popover": "0 0% 100%",
        "popoverForeground": "240 10% 3.9%",
        "primary": "240 5.9% 10%",
        "primaryForeground": "0 0% 98%",
        "secondary": "240 4.8% 95.9%",
        "secondaryForeground": "240 5.9% 10%",
        "muted": "240 4.8% 95.9%",
        "mutedForeground": "240 3.8% 46.1%",
        "accent": "240 4.8% 95.9%",
        "accentForeground": "240 5.9% 10%",
        "destructive": "0 84.2% 60.2%",
        "destructiveForeground": "0 0% 98%",
        "border": "240 5.9% 90%",
        "input": "240 5.9% 90%",
        "ring": "240 5.9% 10%"
      },
      "darkColors": {
        "background": "240 10% 3.9%",
        "foreground": "0 0% 98%",
        "card": "240 10% 3.9%",
        "cardForeground": "0 0% 98%",
        "popover": "240 10% 3.9%",
        "popoverForeground": "0 0% 98%",
        "primary": "0 0% 98%",
        "primaryForeground": "240 5.9% 10%",
        "secondary": "240 3.7% 15.9%",
        "secondaryForeground": "0 0% 98%",
        "muted": "240 3.7% 15.9%",
        "mutedForeground": "240 5% 64.9%",
        "accent": "240 3.7% 15.9%",
        "accentForeground": "0 0% 98%",
        "destructive": "0 62.8% 30.6%",
        "destructiveForeground": "0 0% 98%",
        "border": "240 3.7% 15.9%",
        "input": "240 3.7% 15.9%",
        "ring": "240 4.9% 83.9%"
      },
      "typography": {
        "fontHeading": "Inter",
        "fontBody": "Inter",
        "fontMono": "JetBrains Mono",
        "fontSizeBase": "1rem",
        "lineHeightBase": "1.5",
        "fontWeightBase": "400"
      },
      "spacing": {
        "radius": "0.5rem",
        "buttonRadius": "0.5rem",
        "cardRadius": "0.5rem",
        "inputRadius": "0.5rem",
        "pillButtons": false,
        "borderWidth": "1px",
        "containerWidth": "1280px",
        "spacingScale": "1"
      },
      "effects": {
        "shadowIntensity": 20,
        "shadowColor": "220 3% 15%",
        "shadowBlur": "8px",
        "elevationPreset": "soft",
        "transitionSpeed": "200ms",
        "reduceMotion": false,
        "hoverIntensity": "medium"
      },
      "mode": "light"
    }
  }
]`

func TestCheckPresets_ValidFile(t *testing.T) {
	dir := t.TempDir()
	writeFile(t, dir, "presets.json", minimalValidPresetJSON)

	violations := checkPresets(dir)
	if len(violations) != 0 {
		t.Fatalf("checkPresets() returned %d violations for valid presets.json, want 0: %#v", len(violations), violations)
	}
}

func TestCheckPresets_EmptyArray(t *testing.T) {
	dir := t.TempDir()
	writeFile(t, dir, "presets.json", `[]`)

	violations := checkPresets(dir)
	if len(violations) != 0 {
		t.Fatalf("checkPresets() returned %d violations for empty array, want 0", len(violations))
	}
}

func TestCheckPresets_MissingID(t *testing.T) {
	dir := t.TempDir()
	// Preset with no "id" field (empty string after decode)
	writeFile(t, dir, "presets.json", `[
  {
    "id": "",
    "name": "My Preset",
    "theme": {}
  }
]`)

	violations := checkPresets(dir)
	if len(violations) == 0 {
		t.Fatal("checkPresets() returned 0 violations for preset with empty id, want >= 1")
	}
	found := false
	for _, v := range violations {
		if containsStr(v.message, "missing \"id\"") {
			found = true
		}
	}
	if !found {
		t.Fatalf("expected 'missing id' violation, got: %#v", violations)
	}
}

func TestCheckPresets_MissingName(t *testing.T) {
	dir := t.TempDir()
	writeFile(t, dir, "presets.json", `[
  {
    "id": "my-id",
    "name": "",
    "theme": {}
  }
]`)

	violations := checkPresets(dir)
	if len(violations) == 0 {
		t.Fatal("checkPresets() returned 0 violations for preset with empty name, want >= 1")
	}
	found := false
	for _, v := range violations {
		if containsStr(v.message, "missing \"name\"") {
			found = true
		}
	}
	if !found {
		t.Fatalf("expected 'missing name' violation, got: %#v", violations)
	}
}

func TestCheckPresets_BothIDAndNameMissing(t *testing.T) {
	dir := t.TempDir()
	writeFile(t, dir, "presets.json", `[
  {
    "id": "",
    "name": "",
    "theme": {}
  }
]`)

	violations := checkPresets(dir)
	if len(violations) < 2 {
		t.Fatalf("checkPresets() returned %d violations, want at least 2 (id+name): %#v", len(violations), violations)
	}
}

func TestCheckPresets_InvalidJSON(t *testing.T) {
	dir := t.TempDir()
	writeFile(t, dir, "presets.json", `{ this is not valid json`)

	violations := checkPresets(dir)
	if len(violations) == 0 {
		t.Fatal("checkPresets() returned 0 violations for invalid JSON, want >= 1")
	}
	found := false
	for _, v := range violations {
		if containsStr(v.message, "invalid JSON") {
			found = true
		}
	}
	if !found {
		t.Fatalf("expected 'invalid JSON' violation, got: %#v", violations)
	}
}

func TestCheckPresets_UnknownField(t *testing.T) {
	dir := t.TempDir()
	// Valid except for an extra unknown field — triggers "stale preset data" path
	writeFile(t, dir, "presets.json", `[
  {
    "id": "test",
    "name": "Test",
    "unknownExtraField": "oops",
    "theme": {}
  }
]`)

	violations := checkPresets(dir)
	if len(violations) == 0 {
		t.Fatal("checkPresets() returned 0 violations for unknown field, want >= 1")
	}
	found := false
	for _, v := range violations {
		if containsStr(v.message, "unknown fields") || containsStr(v.message, "stale preset data") {
			found = true
		}
	}
	if !found {
		t.Fatalf("expected 'unknown fields' violation, got: %#v", violations)
	}
}

func TestCheckPresets_NoPresetsFileReturnsClean(t *testing.T) {
	dir := t.TempDir()
	// No presets.json at all — should return 0 violations
	violations := checkPresets(dir)
	if len(violations) != 0 {
		t.Fatalf("checkPresets() returned %d violations for dir without presets.json, want 0", len(violations))
	}
}

func TestFindPresetsFiles_SkipsVendorAndWeb(t *testing.T) {
	root := t.TempDir()

	// Legitimate presets.json at root level
	writeFile(t, root, "presets.json", `[]`)

	// Should be skipped (vendor/)
	vendorDir := filepath.Join(root, "vendor", "somelib")
	if err := os.MkdirAll(vendorDir, 0755); err != nil {
		t.Fatalf("mkdir vendor: %v", err)
	}
	writeFile(t, vendorDir, "presets.json", `[]`)

	// Should be skipped (web/)
	webDir := filepath.Join(root, "web", "src")
	if err := os.MkdirAll(webDir, 0755); err != nil {
		t.Fatalf("mkdir web: %v", err)
	}
	writeFile(t, webDir, "presets.json", `[]`)

	files := findPresetsFiles(root)
	if len(files) != 1 {
		t.Fatalf("findPresetsFiles() returned %d files, want 1 (only root-level): %v", len(files), files)
	}
}

func TestFindPresetsFiles_FindsInSubdir(t *testing.T) {
	root := t.TempDir()
	pluginDir := filepath.Join(root, "internal", "plugins", "myplugin")
	if err := os.MkdirAll(pluginDir, 0755); err != nil {
		t.Fatalf("mkdir plugin: %v", err)
	}
	writeFile(t, pluginDir, "presets.json", `[]`)

	files := findPresetsFiles(root)
	if len(files) != 1 {
		t.Fatalf("findPresetsFiles() returned %d files, want 1: %v", len(files), files)
	}
}

// containsStr is a helper to test substring containment.
func containsStr(s, substr string) bool {
	return len(s) > 0 && len(substr) > 0 && func() bool {
		for i := 0; i <= len(s)-len(substr); i++ {
			if s[i:i+len(substr)] == substr {
				return true
			}
		}
		return false
	}()
}