package reader

import (
	"reflect"
	"testing"
	"time"
)

func TestORPIndex(t *testing.T) {
	tests := []struct {
		name     string
		word     string
		expected int
	}{
		{"empty", "", 0},
		{"one character", "a", 0},
		{"two characters", "go", 1},
		{"three characters", "cat", 1},
		{"five characters", "hello", 1},
		{"six characters", "reader", 2},
		{"nine characters", "wonderful", 2},
		{"ten characters", "technology", 3},
		{"long word", "extraordinary", 3},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got := ORPIndex([]rune(tt.word))

			if got != tt.expected {
				t.Errorf("ORPIndex(%q) = %d, want %d",
					tt.word, got, tt.expected)
			}
		})
	}
}

func TestSplitWord(t *testing.T) {
	tests := []struct {
		name     string
		input    string
		expected Word
	}{
		{
			name:  "normal word",
			input: "hello",
			expected: Word{
				Text:   "hello",
				Prefix: "h",
				Focus:  "e",
				Suffix: "llo",
			},
		},
		{
			name:  "unicode word",
			input: "café",
			expected: Word{
				Text:   "café",
				Prefix: "c",
				Focus:  "a",
				Suffix: "fé",
			},
		},
		{
			name:  "emoji",
			input: "🙂hello",
			expected: Word{
				Text:   "🙂hello",
				Prefix: "🙂h",
				Focus:  "e",
				Suffix: "llo",
			},
		},
		{
			name:     "empty word",
			input:    "",
			expected: Word{},
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got := SplitWord(tt.input)

			if !reflect.DeepEqual(got, tt.expected) {
				t.Errorf("SplitWord(%q) = %+v, want %+v",
					tt.input, got, tt.expected)
			}
		})
	}
}

func TestTokenize(t *testing.T) {
	tests := []struct {
		name          string
		input         string
		expectedCount int
	}{
		{"normal text", "Hello world", 2},
		{"multiple spaces", "Hello    world", 2},
		{"newlines", "Hello\nworld", 2},
		{"tabs", "Hello\tworld", 2},
		{"mixed whitespace", " Hello\n world\tagain ", 3},
		{"empty input", "", 0},
		{"whitespace only", "   \n\t ", 0},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got := Tokenize(tt.input)

			if len(got) != tt.expectedCount {
				t.Errorf("Tokenize(%q) returned %d words, want %d",
					tt.input, len(got), tt.expectedCount)
			}
		})
	}
}

func TestTokenizePreservesWords(t *testing.T) {
	input := "Hello, world!"
	words := Tokenize(input)

	expected := []string{"Hello,", "world!"}

	for i, word := range words {
		if word.Text != expected[i] {
			t.Errorf("word %d = %q, want %q",
				i, word.Text, expected[i])
		}
	}
}

func TestIsSentenceEnding(t *testing.T) {
	tests := []struct {
		word     string
		expected bool
	}{
		{"hello.", true},
		{"hello!", true},
		{"hello?", true},
		{"hello…", true},
		{`hello."`, true},
		{"hello!)", true},
		{"hello", false},
		{"hello,", false},
		{"", false},
	}

	for _, tt := range tests {
		t.Run(tt.word, func(t *testing.T) {
			got := IsSentenceEnding(tt.word)

			if got != tt.expected {
				t.Errorf("IsSentenceEnding(%q) = %t, want %t",
					tt.word, got, tt.expected)
			}
		})
	}
}

func TestIsPausePunctuation(t *testing.T) {
	tests := []struct {
		word     string
		expected bool
	}{
		{"hello,", true},
		{"hello;", true},
		{"hello:", true},
		{`hello,"`, true},
		{"hello", false},
		{"hello.", false},
		{"", false},
	}

	for _, tt := range tests {
		t.Run(tt.word, func(t *testing.T) {
			got := IsPausePunctuation(tt.word)

			if got != tt.expected {
				t.Errorf("IsPausePunctuation(%q) = %t, want %t",
					tt.word, got, tt.expected)
			}
		})
	}
}

func TestWordDuration(t *testing.T) {
	tests := []struct {
		name     string
		word     string
		wpm      int
		expected time.Duration
	}{
		{
			name:     "normal word",
			word:     "hello",
			wpm:      300,
			expected: 200 * time.Millisecond,
		},
		{
			name:     "sentence ending",
			word:     "hello.",
			wpm:      300,
			expected: 500 * time.Millisecond,
		},
		{
			name:     "comma pause",
			word:     "hello,",
			wpm:      300,
			expected: 350 * time.Millisecond,
		},
		{
			name:     "long word",
			word:     "extraordinary",
			wpm:      300,
			expected: 250 * time.Millisecond,
		},
		{
			name:     "sentence ending and long word",
			word:     "extraordinary.",
			wpm:      300,
			expected: 550 * time.Millisecond,
		},
		{
			name:     "minimum WPM clamp",
			word:     "hello",
			wpm:      50,
			expected: 600 * time.Millisecond,
		},
		{
			name:     "maximum WPM clamp",
			word:     "hello",
			wpm:      1500,
			expected: 60 * time.Millisecond,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got := WordDuration(tt.word, tt.wpm)

			if got != tt.expected {
				t.Errorf("WordDuration(%q, %d) = %v, want %v",
					tt.word, tt.wpm, got, tt.expected)
			}
		})
	}
}

func TestRuneLength(t *testing.T) {
	tests := []struct {
		word     string
		expected int
	}{
		{"hello", 5},
		{"café", 4},
		{"🙂", 1},
		{"🙂hello", 6},
		{"", 0},
	}

	for _, tt := range tests {
		t.Run(tt.word, func(t *testing.T) {
			got := RuneLength(tt.word)

			if got != tt.expected {
				t.Errorf("RuneLength(%q) = %d, want %d",
					tt.word, got, tt.expected)
			}
		})
	}
}