# SPDX-License-Identifier: LGPL-2.1-only
# Copyright 2022 Jookia <contact@jookia.org>

from hypothesis import assume, given
from hypothesis.strategies import (
    booleans,
    integers,
    composite,
    lists,
    one_of,
)

from src.parse import (
    NoteSkipper,
    ParseContext,
    ParseError,
    ParseErrorException,
    ParseTask,
)
from src.syntax import SyntaxStream, SyntaxType
from tests.test_syntax import (
    draw_token_by_value,
    draw_syntax_random,
    draw_syntax_token,
)


# Inserts an element at a random place in a list
def insert_random(draw, list, data):
    pos = draw(integers(min_value=1, max_value=(len(list) - 1)))
    new_data = list[0:pos] + [data] + list[pos:]
    return new_data


# Draws a random token suitable for note building
@composite
def draw_note_value_token(draw):
    token = draw(draw_syntax_token())
    assume(token.value not in ["StartNote", "EndNote"])
    return token


# Draws tokens to make a valid note
@composite
def draw_syntax_note_valid(draw):
    tokens = draw(lists(draw_note_value_token()))
    start = draw(draw_token_by_value("StartNote"))
    end = draw(draw_token_by_value("EndNote"))
    all_tokens = [start] + tokens + [end]
    return all_tokens


# Tests skip_note works correctly
# We expect the following behaviour:
# - Only the note expression is parsed
# - No value is returned
# - All tokens are consumed up to and including EndNote
@given(draw_syntax_random(), draw_syntax_note_valid())
def test_parse_note_valid(canary, test_data):
    tokens = test_data
    stream = SyntaxStream(tokens + [canary])
    skipped = NoteSkipper().skip_note(stream)
    assert skipped is None
    assert stream.pop() == canary
    assert stream.pop() is None


# Generate note without StartNote
# We expect the following behaviour:
# - Error if there is no StartNote node at all
# - Error if StartNote is not a SyntaxType.TOKEN
# - Error if StartNote's token value is not "StartNote"
@composite
def draw_syntax_note_invalid_nostartnote(draw):
    tokens = draw(draw_syntax_note_valid())
    if draw(booleans()):
        token = draw(draw_syntax_random())
        assume(not (token.type == SyntaxType.TOKEN and token.value == "StartNote"))
        new_tokens = [token] + tokens[1:0]
        context = ParseContext(ParseTask.PARSE_NOTE, new_tokens[0], None)
        if token.type == SyntaxType.TOKEN:
            error = ParseErrorException(
                ParseError.WRONG_TOKEN, token, "StartNote", context
            )
        else:
            error = ParseErrorException(ParseError.NOT_TOKEN, token, None, context)
        return (new_tokens, error)
    else:
        context = ParseContext(ParseTask.PARSE_NOTE, None, None)
        error = ParseErrorException(ParseError.NO_TOKEN, None, None, context)
        return ([], error)


# Generate note with a StartNote token in it
# We expect the following behaviour:
# - Error if a StartNote token is in the note content
@composite
def draw_syntax_note_invalid_extrastartnote(draw):
    tokens = draw(draw_syntax_note_valid())
    start = draw(draw_token_by_value("StartNote"))
    new_tokens = insert_random(draw, tokens, start)
    context = ParseContext(ParseTask.PARSE_NOTE, new_tokens[0], None)
    error = ParseErrorException(ParseError.FOUND_STARTNOTE, start, None, context)
    return (new_tokens, error)


# Generate note without EndNote
# We expect the following behaviour:
# - Error if there is no EndNote node at all
@composite
def draw_syntax_note_invalid_noendnote(draw):
    tokens = draw(draw_syntax_note_valid())
    context = ParseContext(ParseTask.PARSE_NOTE, tokens[0], None)
    error = ParseErrorException(ParseError.NO_TOKEN, None, None, context)
    return (tokens[0:-1], error)


# Generate an invalid note case
@composite
def draw_syntax_note_invalid(draw):
    strategies = [
        draw_syntax_note_invalid_nostartnote(),
        draw_syntax_note_invalid_extrastartnote(),
        draw_syntax_note_invalid_noendnote(),
    ]
    return draw(one_of(strategies))


# Test that parse_note errors in invalid cases
@given(draw_syntax_note_invalid())
def test_parse_note_invalid(test_data):
    (tokens, error) = test_data
    stream = SyntaxStream(tokens)
    try:
        parsed = NoteSkipper().skip_note(stream)
        raise AssertionError("Parsed invalid data: %s" % (parsed))
    except ParseErrorException as e:
        assert e == error