package prompt

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

// mockReader implements the Reader interface for testing
type mockReader struct {
	input string
	pos   int
}

func (m *mockReader) ReadString(delim byte) (string, error) {
	if m.pos >= len(m.input) {
		return "", io.EOF
	}

	idx := strings.IndexByte(m.input[m.pos:], delim)
	if idx == -1 {
		result := m.input[m.pos:]
		m.pos = len(m.input)
		return result, nil
	}

	result := m.input[m.pos : m.pos+idx+1]
	m.pos += idx + 1
	return result, nil
}

func TestPromptStringWithReader(t *testing.T) {
	tests := []struct {
		name         string
		input        string
		defaultValue string
		required     bool
		expected     string
		expectError  bool
	}{
		{
			name:         "user enters value",
			input:        "testvalue\n",
			defaultValue: "default",
			required:     false,
			expected:     "testvalue",
			expectError:  false,
		},
		{
			name:         "user accepts default",
			input:        "\n",
			defaultValue: "default",
			required:     false,
			expected:     "default",
			expectError:  false,
		},
		{
			name:         "required field empty then filled",
			input:        "\nactualvalue\n",
			defaultValue: "",
			required:     true,
			expected:     "actualvalue",
			expectError:  false,
		},
		{
			name:         "optional empty field",
			input:        "\n",
			defaultValue: "",
			required:     false,
			expected:     "",
			expectError:  false,
		},
		{
			name:         "whitespace trimmed",
			input:        "  test  \n",
			defaultValue: "",
			required:     false,
			expected:     "test",
			expectError:  false,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			reader := &mockReader{input: tt.input}
			result, err := promptStringWithReader(reader, "Test Label", tt.defaultValue, tt.required)

			if (err != nil) != tt.expectError {
				t.Errorf("Expected error: %v, got: %v", tt.expectError, err)
			}

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

func TestPromptIntWithReader(t *testing.T) {
	tests := []struct {
		name         string
		input        string
		defaultValue int
		required     bool
		expected     int
		expectError  bool
	}{
		{
			name:         "user enters valid number",
			input:        "42\n",
			defaultValue: 0,
			required:     false,
			expected:     42,
			expectError:  false,
		},
		{
			name:         "user accepts default",
			input:        "\n",
			defaultValue: 5432,
			required:     false,
			expected:     5432,
			expectError:  false,
		},
		{
			name:         "invalid then valid number",
			input:        "abc\n123\n",
			defaultValue: 0,
			required:     false,
			expected:     123,
			expectError:  false,
		},
		{
			name:         "required field empty then filled",
			input:        "\n999\n",
			defaultValue: 0,
			required:     true,
			expected:     999,
			expectError:  false,
		},
		{
			name:         "zero value",
			input:        "0\n",
			defaultValue: 10,
			required:     false,
			expected:     0,
			expectError:  false,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			reader := &mockReader{input: tt.input}
			result, err := promptIntWithReader(reader, "Test Label", tt.defaultValue, tt.required)

			if (err != nil) != tt.expectError {
				t.Errorf("Expected error: %v, got: %v", tt.expectError, err)
			}

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

func TestValidateDirectory(t *testing.T) {
	// Create a temporary directory for testing
	tmpDir := t.TempDir()

	tests := []struct {
		name        string
		path        string
		setup       func() string
		expectError bool
	}{
		{
			name: "existing directory",
			setup: func() string {
				return tmpDir
			},
			expectError: false,
		},
		{
			name: "non-existent directory gets created",
			setup: func() string {
				return filepath.Join(tmpDir, "newdir")
			},
			expectError: false,
		},
		{
			name: "nested directory gets created",
			setup: func() string {
				return filepath.Join(tmpDir, "level1", "level2", "level3")
			},
			expectError: false,
		},
		{
			name: "file exists at path",
			setup: func() string {
				filePath := filepath.Join(tmpDir, "testfile")
				os.WriteFile(filePath, []byte("test"), 0644)
				return filePath
			},
			expectError: true,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			path := tt.setup()
			err := ValidateDirectory(path)

			if (err != nil) != tt.expectError {
				t.Errorf("Expected error: %v, got: %v", tt.expectError, err)
			}

			// If no error expected, verify directory exists
			if !tt.expectError {
				info, err := os.Stat(path)
				if err != nil {
					t.Errorf("Directory should exist: %v", err)
				}
				if !info.IsDir() {
					t.Errorf("Path should be a directory")
				}
			}
		})
	}
}

func TestPrintFunctions(t *testing.T) {
	// These functions write to stdout, so we just ensure they don't panic
	// Testing colored output is complex due to terminal color codes

	tests := []struct {
		name string
		fn   func()
	}{
		{"PrintHeader", func() { PrintHeader("Test Header") }},
		{"PrintSuccess", func() { PrintSuccess("Success message") }},
		{"PrintError", func() { PrintError("Error message") }},
		{"PrintInfo", func() { PrintInfo("Info message") }},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			// Just ensure the function doesn't panic
			defer func() {
				if r := recover(); r != nil {
					t.Errorf("Function panicked: %v", r)
				}
			}()

			tt.fn()
		})
	}
}

func TestPromptDirectory(t *testing.T) {
	tmpDir := t.TempDir()

	tests := []struct {
		name         string
		input        string
		defaultValue string
		required     bool
		expectError  bool
	}{
		{
			name:         "valid directory path",
			input:        tmpDir + "\n",
			defaultValue: "",
			required:     true,
			expectError:  false,
		},
		{
			name:         "creates new directory",
			input:        filepath.Join(tmpDir, "newdir") + "\n",
			defaultValue: "",
			required:     true,
			expectError:  false,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			// Note: This test would require refactoring PromptDirectory to accept a reader
			// For now, we test ValidateDirectory which is the core logic
			if tt.input != "" {
				path := strings.TrimSpace(tt.input[:len(tt.input)-1])
				err := ValidateDirectory(path)
				if (err != nil) != tt.expectError {
					t.Errorf("Expected error: %v, got: %v", tt.expectError, err)
				}
			}
		})
	}
}

// Benchmark tests
func BenchmarkPromptStringWithReader(b *testing.B) {
	reader := &mockReader{input: strings.Repeat("test\n", b.N)}
	b.ResetTimer()

	for i := 0; i < b.N; i++ {
		promptStringWithReader(reader, "Label", "default", false)
	}
}

func BenchmarkPromptIntWithReader(b *testing.B) {
	reader := &mockReader{input: strings.Repeat("42\n", b.N)}
	b.ResetTimer()

	for i := 0; i < b.N; i++ {
		promptIntWithReader(reader, "Label", 0, false)
	}
}