package main

import (
	"bytes"
	"io"
	"os"
	"strings"
	"testing"
	"time"

	tea "github.com/charmbracelet/bubbletea"
)

// assertEqual checks if two values are equal and reports an error if they are not.
func assertEqual(t *testing.T, actual, expected interface{}, msg string) {
	t.Helper()

	if actual != expected {
		t.Errorf("%s: expected %v, got %v", msg, expected, actual)
	}
}

// assertNotEqual checks if two values are not equal and reports an error if they are.
func assertNotEqual(t *testing.T, actual, expected interface{}, msg string) {
	t.Helper()

	if actual == expected {
		t.Errorf("%s: expected %v to be different from %v", msg, actual, expected)
	}
}

// TestParseDuration tests the parseDuration function
func TestParseDuration(t *testing.T) {
	tests := []struct {
		input    string
		expected time.Duration
		hasError bool
	}{
		{"10", 10 * time.Minute, false},
		{"1h", 1 * time.Hour, false},
		{"invalid", 0, true},
	}

	for _, test := range tests {
		result, err := parseDuration(test.input)
		if test.hasError {
			assertNotEqual(t, err, nil, "Expected an error for input "+test.input)
		} else {
			assertEqual(t, err, nil, "Did not expect an error for input "+test.input)
			assertEqual(t, result, test.expected, "Expected duration for input "+test.input)
		}
	}
}

// TestRunCommands tests the runCommands function
func TestRunCommands(t *testing.T) {
	r, w, err := os.Pipe()
	if err != nil {
		t.Fatal(err)
	}

	// Redirect stdout and stderr to the pipe
	oldStdout := os.Stdout
	oldStderr := os.Stderr
	os.Stdout = w
	os.Stderr = w

	t.Cleanup(func() {
		os.Stdout = oldStdout
		os.Stderr = oldStderr

		w.Close()
	})

	m := model{}
	m.runCommands([]string{"echo Hello, World!"})

	w.Close()

	var buf bytes.Buffer

	if _, err = io.Copy(&buf, r); err != nil {
		t.Fatal(err)
	}

	output := buf.String()
	assertEqual(t, strings.Contains(output, "Hello, World!"), true, "Expected output to contain 'Hello, World!'")
}

// TestInputView tests the Update method of the model for the input view
func TestInputView(t *testing.T) {
	m := initialModel(false, "#ffdd57", "#57ddff")
	m.View()

	assertEqual(t, m.currentScreen, inputScreen, "Expected currentScreen to be inputScreen")
	assertEqual(t, m.focusIndex, 0, "Expected focusIndex to be 0")

	m.inputs[m.focusIndex].SetValue("10")

	var msg tea.Msg

	// Test tab key press
	msg = tea.KeyMsg{Type: tea.KeyTab}
	updatedModel, _ := m.Update(msg)
	m = updatedModel.(model)
	assertEqual(t, m.focusIndex, 1, "Expected focusIndex to be 1")

	// Test shift+tab key press
	msg = tea.KeyMsg{Type: tea.KeyShiftTab}
	updatedModel, _ = m.Update(msg)
	m = updatedModel.(model)
	assertEqual(t, m.focusIndex, 0, "Expected focusIndex to be 0")

	// Enter last value and test enter key press
	for i := m.focusIndex; i < 2; i++ {
		msg = tea.KeyMsg{Type: tea.KeyTab}
		updatedModel, _ = m.Update(msg)
		m = updatedModel.(model)
		m.inputs[m.focusIndex].SetValue("10")
	}

	msg = tea.KeyMsg{Type: tea.KeyEnter}
	updatedModel, resultCmd := m.Update(msg)
	m = updatedModel.(model)

	assertEqual(t, m.err, nil, "Expected no error")
	assertNotEqual(t, resultCmd, nil, "Expected resultCmd to be not nil")
	assertEqual(t, m.currentScreen, timerScreen, "Expected currentScreen to be timerScreen")
	assertEqual(t, m.remaining, 10*time.Minute, "Expected remaining to be 10 minutes")

	// Test timer view
	m.View()

	oneSec := timeMsg(time.Now().Add(1 * time.Second))
	updatedModel, _ = m.Update(oneSec)
	m = updatedModel.(model)

	assertEqual(t, m.state, "Focus", "Expected state to be 'Focus'")
	assertEqual(t, m.remaining, 9*time.Minute+59*time.Second, "Expected remaining to be 9 minutes 59 seconds")

	// Test switch to break time
	m.remaining = 0
	updatedModel, _ = m.Update(oneSec)
	m = updatedModel.(model)

	assertEqual(t, m.state, "Break", "Expected state to be 'Break'")
	assertEqual(t, m.remaining, 9*time.Minute+59*time.Second, "Expected remaining to be 9 minutes 59 seconds")

	// Switch back to focus time
	m.remaining = 0
	updatedModel, _ = m.Update(oneSec)
	m = updatedModel.(model)

	assertEqual(t, m.state, "Focus", "Expected state to be 'Focus'")
	assertEqual(t, m.remaining, 9*time.Minute+59*time.Second, "Expected remaining to be 9 minutes 59 seconds")
}