package forward

import (
	"testing"

	"github.com/nvm/kportal/internal/config"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func TestLogWriter_Write(t *testing.T) {
	tests := []struct {
		name          string
		prefix        string
		input         string
		expectedInLog string
		description   string
	}{
		{
			name:          "write simple message",
			prefix:        "[worker] ",
			input:         "test message",
			expectedInLog: "[worker] test message",
			description:   "Should write message with prefix to log",
		},
		{
			name:          "write empty message",
			prefix:        "[test] ",
			input:         "",
			expectedInLog: "[test] ",
			description:   "Should handle empty message",
		},
		{
			name:          "write multiline message",
			prefix:        "[fwd] ",
			input:         "line1\nline2",
			expectedInLog: "[fwd] line1\nline2",
			description:   "Should handle multiline messages",
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			// Test logWriter
			originalWriter := &logWriter{prefix: tt.prefix}

			n, err := originalWriter.Write([]byte(tt.input))

			require.NoError(t, err, "Write should not return error")
			assert.Equal(t, len(tt.input), n, "Write should return number of bytes written")
		})
	}
}

func TestForwardWorker_GetForward(t *testing.T) {
	tests := []struct {
		name        string
		forward     config.Forward
		description string
	}{
		{
			name: "get pod forward",
			forward: config.Forward{
				Resource:  "pod/my-app",
				LocalPort: 8080,
				Port:      80,
				Protocol:  "tcp",
			},
			description: "Should return the forward configuration",
		},
		{
			name: "get service forward",
			forward: config.Forward{
				Resource:  "service/postgres",
				LocalPort: 5432,
				Port:      5432,
				Protocol:  "tcp",
			},
			description: "Should return service forward configuration",
		},
		{
			name: "get forward with selector",
			forward: config.Forward{
				Resource:  "pod",
				Selector:  "app=nginx,env=prod",
				LocalPort: 8080,
				Port:      80,
				Protocol:  "tcp",
			},
			description: "Should return forward with label selector",
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			// Note: We can't easily test the full worker lifecycle without mocks,
			// but we can test the constructor and simple getters

			// This test would require proper mocking setup
			// For now, we'll test the Forward struct directly

			id := tt.forward.ID()
			assert.NotEmpty(t, id, "Forward should have an ID")

			forwardStr := tt.forward.String()
			assert.NotEmpty(t, forwardStr, "Forward should have a string representation")
			assert.Contains(t, forwardStr, tt.forward.Resource, "String should contain resource")
		})
	}
}

func TestForwardWorker_IsRunning(t *testing.T) {
	// This is a basic test of the goroutine state tracking
	// Full integration tests would require mock dependencies

	t.Run("worker state tracking", func(t *testing.T) {
		// Test the concept of the done channel
		doneChan := make(chan struct{})

		// Initially, channel is open (worker would be running)
		select {
		case <-doneChan:
			t.Fatal("doneChan should be open initially")
		default:
			// Expected: channel is open
		}

		// Close the channel (simulating worker done)
		close(doneChan)

		// Now channel should be closed
		select {
		case <-doneChan:
			// Expected: channel is closed
		default:
			t.Fatal("doneChan should be closed after close")
		}
	})
}

func TestForwardID(t *testing.T) {
	tests := []struct {
		name         string
		forward      config.Forward
		expectUnique bool
		description  string
	}{
		{
			name: "unique IDs for different forwards",
			forward: config.Forward{
				Resource:  "pod/app1",
				LocalPort: 8080,
				Port:      80,
			},
			expectUnique: true,
			description:  "Different forwards should have different IDs",
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			id1 := tt.forward.ID()

			// Create a different forward
			fwd2 := config.Forward{
				Resource:  "pod/app2",
				LocalPort: 8081,
				Port:      80,
			}
			id2 := fwd2.ID()

			if tt.expectUnique {
				assert.NotEqual(t, id1, id2, "Different forwards should have different IDs")
			}

			// Same forward should produce same ID
			id3 := tt.forward.ID()
			assert.Equal(t, id1, id3, "Same forward should produce same ID")
		})
	}
}

func TestForwardString(t *testing.T) {
	tests := []struct {
		name             string
		forward          config.Forward
		expectedContains []string
		description      string
	}{
		{
			name: "pod forward string",
			forward: config.Forward{
				Resource:  "pod/my-app",
				LocalPort: 8080,
				Port:      80,
			},
			expectedContains: []string{"pod/my-app", "8080", "80"},
			description:      "Should contain resource and ports",
		},
		{
			name: "service forward string",
			forward: config.Forward{
				Resource:  "service/postgres",
				LocalPort: 5432,
				Port:      5432,
			},
			expectedContains: []string{"service/postgres", "5432"},
			description:      "Should contain service and port",
		},
		{
			name: "selector forward string",
			forward: config.Forward{
				Resource:  "pod",
				Selector:  "app=nginx",
				LocalPort: 8080,
				Port:      80,
			},
			expectedContains: []string{"app=nginx", "8080", "80"},
			description:      "Should contain selector and ports",
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			result := tt.forward.String()

			assert.NotEmpty(t, result, "String representation should not be empty")

			for _, expected := range tt.expectedContains {
				assert.Contains(t, result, expected,
					"String should contain %s", expected)
			}
		})
	}
}

func TestSleepWithBackoffConcept(t *testing.T) {
	// Test the backoff concept without actually running a worker
	t.Run("backoff delay increases", func(t *testing.T) {
		// This tests the retry backoff behavior conceptually
		delays := []int{1, 2, 4, 8, 10, 10, 10}

		for i, expected := range delays {
			// Simulate backoff calculation
			delay := 1
			for j := 0; j < i; j++ {
				delay *= 2
				if delay > 10 {
					delay = 10
				}
			}

			assert.Equal(t, expected, delay,
				"Backoff at attempt %d should be %d", i, expected)
		}
	})
}

func TestWorkerVerboseMode(t *testing.T) {
	tests := []struct {
		name        string
		verbose     bool
		description string
	}{
		{
			name:        "verbose mode enabled",
			verbose:     true,
			description: "Worker should respect verbose flag",
		},
		{
			name:        "verbose mode disabled",
			verbose:     false,
			description: "Worker should respect non-verbose flag",
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			// Test that verbose flag is a boolean
			assert.IsType(t, bool(true), tt.verbose)

			// In a real worker, this would control logging
			// For now, we just verify the type
		})
	}
}