package fileparser

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

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
)

func TestExtractText_EmptyData(t *testing.T) {
	result, err := ExtractText(nil, "test.txt")
	assert.NoError(t, err)
	assert.Empty(t, result)

	result, err = ExtractText([]byte{}, "test.txt")
	assert.NoError(t, err)
	assert.Empty(t, result)
}

func TestExtractText_PlainText(t *testing.T) {
	content := "Тестовый текст для проверки"
	result, err := ExtractText([]byte(content), "document.txt")

	assert.NoError(t, err)
	assert.Equal(t, content, result)
}

func TestExtractText_PlainTextWithNewlines(t *testing.T) {
	content := "Первая строка\nВторая строка\nТретья строка"
	result, err := ExtractText([]byte(content), "document.txt")

	assert.NoError(t, err)
	assert.Equal(t, content, result)
}

func TestExtractText_RealDocxFile(t *testing.T) {
	testdataPath := filepath.Join("testdata", "test_document.docx")
	data, err := os.ReadFile(testdataPath)
	require.NoError(t, err, "не удалось прочитать тестовый файл")

	result, err := ExtractText(data, "тестовый.docx")

	assert.NoError(t, err)
	assert.NotEmpty(t, result, "текст из docx не должен быть пустым")
	t.Logf("Извлеченный текст из docx:\n%s", result)
}

func TestExtractText_DocxWithAnyFilename(t *testing.T) {
	testdataPath := filepath.Join("testdata", "test_document.docx")
	data, err := os.ReadFile(testdataPath)
	require.NoError(t, err)

	result1, err := ExtractText(data, "random_name_without_extension")
	assert.NoError(t, err)
	assert.NotEmpty(t, result1)

	result2, err := ExtractText(data, "document.pdf")
	assert.NoError(t, err)
	assert.NotEmpty(t, result2)

	assert.Equal(t, result1, result2, "результат должен быть одинаковым независимо от имени файла")
}

func TestExtractText_UnsupportedFormat_PDF(t *testing.T) {
	pdfHeader := []byte("%PDF-1.4\n")
	result, err := ExtractText(pdfHeader, "document.pdf")

	assert.Error(t, err)
	assert.Empty(t, result)
	assert.Contains(t, err.Error(), "UNSUPPORTED_FILE_FORMAT")
}

func TestExtractText_UnsupportedFormat_Image(t *testing.T) {
	pngHeader := []byte{0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0A}
	result, err := ExtractText(pngHeader, "image.png")

	assert.Error(t, err)
	assert.Empty(t, result)
	assert.Contains(t, err.Error(), "UNSUPPORTED_FILE_FORMAT")
}

func TestExtractText_InvalidDocx(t *testing.T) {
	zipHeader := []byte{0x50, 0x4B, 0x03, 0x04}
	fakeZip := append(zipHeader, []byte("not a valid zip content")...)

	result, err := ExtractText(fakeZip, "fake.docx")

	assert.Error(t, err)
	assert.Empty(t, result)
}

func TestIsDocx_ValidDocx(t *testing.T) {
	testdataPath := filepath.Join("testdata", "test_document.docx")
	data, err := os.ReadFile(testdataPath)
	require.NoError(t, err)

	assert.True(t, isDocx(data))
}

func TestIsDocx_RegularZip(t *testing.T) {
	zipHeader := []byte{0x50, 0x4B, 0x03, 0x04}
	assert.False(t, isDocx(zipHeader))
}

func TestIsDocx_NotZip(t *testing.T) {
	textData := []byte("plain text content")
	assert.False(t, isDocx(textData))
}