"""
Tests for DSL autocompletion utilities.

Tests for line extraction, word boundaries, comment/string detection,
and indentation functions.
"""

import pytest
from myfasthtml.core.dsl.types import Position, WordRange
from myfasthtml.core.dsl.utils import (
    get_line_at,
    get_line_up_to_cursor,
    get_lines_up_to,
    find_word_boundaries,
    get_prefix,
    is_in_comment,
    is_in_string,
    get_indentation,
    is_indented,
    strip_quotes,
)


# =============================================================================
# Line Extraction Tests
# =============================================================================


def test_i_can_get_line_at_valid_index():
    """Test that get_line_at returns the correct line."""
    text = "line0\nline1\nline2"
    assert get_line_at(text, 0) == "line0"
    assert get_line_at(text, 1) == "line1"
    assert get_line_at(text, 2) == "line2"


def test_i_can_get_line_at_invalid_index():
    """Test that get_line_at returns empty string for invalid index."""
    text = "line0\nline1"
    assert get_line_at(text, -1) == ""
    assert get_line_at(text, 5) == ""


def test_i_can_get_line_up_to_cursor():
    """Test that get_line_up_to_cursor truncates at cursor position."""
    text = "hello world\nfoo bar"
    cursor = Position(line=0, ch=5)
    assert get_line_up_to_cursor(text, cursor) == "hello"

    cursor = Position(line=1, ch=3)
    assert get_line_up_to_cursor(text, cursor) == "foo"


def test_i_can_get_lines_up_to():
    """Test that get_lines_up_to returns lines 0..N."""
    text = "line0\nline1\nline2\nline3"
    assert get_lines_up_to(text, 0) == ["line0"]
    assert get_lines_up_to(text, 2) == ["line0", "line1", "line2"]


# =============================================================================
# Word Boundaries Tests
# =============================================================================


def test_i_can_find_word_boundaries_in_middle():
    """Test word boundaries when cursor is in middle of word."""
    line = "hello world"
    result = find_word_boundaries(line, 3)  # hel|lo
    assert result.start == 0
    assert result.end == 5
    assert result.text == "hello"


def test_i_can_find_word_boundaries_at_start():
    """Test word boundaries when cursor is at start of word."""
    line = "hello world"
    result = find_word_boundaries(line, 0)  # |hello
    assert result.start == 0
    assert result.end == 5
    assert result.text == "hello"


def test_i_can_find_word_boundaries_at_end():
    """Test word boundaries when cursor is at end of word."""
    line = "hello world"
    result = find_word_boundaries(line, 5)  # hello|
    assert result.start == 0
    assert result.end == 5
    assert result.text == "hello"


def test_i_can_find_word_boundaries_with_delimiters():
    """Test word boundaries with delimiter characters like parentheses and quotes."""
    line = 'style("error")'
    result = find_word_boundaries(line, 10)  # style("err|or")
    assert result.start == 7
    assert result.end == 12
    assert result.text == "error"


def test_i_can_find_word_boundaries_empty_line():
    """Test word boundaries on empty line."""
    line = ""
    result = find_word_boundaries(line, 0)
    assert result.start == 0
    assert result.end == 0
    assert result.text == ""


def test_i_can_get_prefix():
    """Test that get_prefix returns text from word start to cursor."""
    line = "style"
    prefix = get_prefix(line, 3)  # sty|le
    assert prefix == "sty"


def test_i_can_get_prefix_at_word_start():
    """Test that get_prefix returns empty at word start."""
    line = "style"
    prefix = get_prefix(line, 0)  # |style
    assert prefix == ""


# =============================================================================
# Comment Detection Tests
# =============================================================================


def test_i_can_detect_comment():
    """Test that cursor after # is detected as in comment."""
    line = "text # comment"
    assert is_in_comment(line, 12) is True  # In "comment"
    assert is_in_comment(line, 7) is True  # Right after #


def test_i_cannot_detect_comment_before_hash():
    """Test that cursor before # is not detected as in comment."""
    line = "text # comment"
    assert is_in_comment(line, 4) is False  # Before #
    assert is_in_comment(line, 0) is False  # At start


def test_i_cannot_detect_comment_hash_in_string():
    """Test that # inside a string is not detected as comment start."""
    line = '"#hash" text'
    assert is_in_comment(line, 9) is False  # After the string


def test_i_can_detect_comment_hash_after_string():
    """Test that # after a string is detected as comment."""
    line = '"text" # comment'
    assert is_in_comment(line, 10) is True


# =============================================================================
# String Detection Tests
# =============================================================================


def test_i_can_detect_string_double_quote():
    """Test detection of cursor inside double-quoted string."""
    line = 'style("error")'
    in_string, quote_char = is_in_string(line, 10)  # Inside "error"
    assert in_string is True
    assert quote_char == '"'


def test_i_can_detect_string_single_quote():
    """Test detection of cursor inside single-quoted string."""
    line = "style('error')"
    in_string, quote_char = is_in_string(line, 10)  # Inside 'error'
    assert in_string is True
    assert quote_char == "'"


def test_i_cannot_detect_string_outside_quotes():
    """Test that cursor outside quotes is not detected as in string."""
    line = 'style("error")'
    in_string, quote_char = is_in_string(line, 3)  # In "style"
    assert in_string is False
    assert quote_char is None


def test_i_cannot_detect_string_after_closing_quote():
    """Test that cursor after closing quote is not in string."""
    line = '"text" other'
    in_string, quote_char = is_in_string(line, 8)
    assert in_string is False
    assert quote_char is None


# =============================================================================
# Indentation Tests
# =============================================================================


def test_i_can_get_indentation_spaces():
    """Test that spaces are counted correctly."""
    line = "    text"
    assert get_indentation(line) == 4


def test_i_can_get_indentation_tabs():
    """Test that tabs are converted to 4 spaces."""
    line = "\ttext"
    assert get_indentation(line) == 4


def test_i_can_get_indentation_mixed():
    """Test mixed spaces and tabs."""
    line = "  \t  text"  # 2 spaces + tab (4) + 2 spaces = 8
    assert get_indentation(line) == 8


def test_i_can_detect_indented_line():
    """Test that indented line is detected."""
    assert is_indented("  text") is True
    assert is_indented("\ttext") is True


def test_i_cannot_detect_indented_for_non_indented():
    """Test that non-indented line is not detected as indented."""
    assert is_indented("text") is False


def test_i_cannot_detect_indented_for_empty_line():
    """Test that empty line is not detected as indented."""
    assert is_indented("") is False


# =============================================================================
# Quote Stripping Tests
# =============================================================================


def test_i_can_strip_quotes_double():
    """Test stripping double quotes."""
    assert strip_quotes('"text"') == "text"


def test_i_can_strip_quotes_single():
    """Test stripping single quotes."""
    assert strip_quotes("'text'") == "text"


def test_i_cannot_strip_quotes_unquoted():
    """Test that unquoted text is returned unchanged."""
    assert strip_quotes("text") == "text"


def test_i_cannot_strip_quotes_mismatched():
    """Test that mismatched quotes are not stripped."""
    assert strip_quotes('"text\'') == '"text\''
    assert strip_quotes("'text\"") == "'text\""


def test_i_cannot_strip_quotes_too_short():
    """Test that text shorter than 2 chars is returned unchanged."""
    assert strip_quotes('"') == '"'
    assert strip_quotes("") == ""