from __future__ import annotations

import os
from io import BytesIO
from pathlib import Path
from typing import AnyStr

import pytest

from PIL import FontFile, Image, ImageDraw, ImageFont, PcfFontFile, _binary

from .helper import (
    assert_image_equal_tofile,
    skip_unless_feature,
)

fontname = "Tests/fonts/10x20-ISO8859-1.pcf"

message = "hello, world"


pytestmark = skip_unless_feature("zlib")


def save_font(request: pytest.FixtureRequest, tmp_path: Path) -> str:
    with open(fontname, "rb") as test_file:
        font = PcfFontFile.PcfFontFile(test_file)
    assert isinstance(font, FontFile.FontFile)
    # check the number of characters in the font
    assert len([_f for _f in font.glyph if _f]) == 223

    tempname = str(tmp_path / "temp.pil")

    def delete_tempfile() -> None:
        try:
            os.remove(tempname[:-4] + ".pbm")
        except OSError:
            pass  # report?

    request.addfinalizer(delete_tempfile)
    font.save(tempname)

    with Image.open(tempname.replace(".pil", ".pbm")) as loaded:
        assert_image_equal_tofile(loaded, "Tests/fonts/10x20.pbm")

    with open(tempname, "rb") as f_loaded:
        with open("Tests/fonts/10x20.pil", "rb") as f_target:
            assert f_loaded.read() == f_target.read()
    return tempname


def test_sanity(request: pytest.FixtureRequest, tmp_path: Path) -> None:
    save_font(request, tmp_path)


def test_less_than_256_characters() -> None:
    with open("Tests/fonts/10x20-ISO8859-1-fewer-characters.pcf", "rb") as test_file:
        font = PcfFontFile.PcfFontFile(test_file)
    assert isinstance(font, FontFile.FontFile)
    # check the number of characters in the font
    assert len([_f for _f in font.glyph if _f]) == 127


def test_invalid_file() -> None:
    with open("Tests/images/flower.jpg", "rb") as fp:
        with pytest.raises(SyntaxError):
            PcfFontFile.PcfFontFile(fp)


def test_draw(request: pytest.FixtureRequest, tmp_path: Path) -> None:
    tempname = save_font(request, tmp_path)
    font = ImageFont.load(tempname)
    im = Image.new("L", (130, 30), "white")
    draw = ImageDraw.Draw(im)
    draw.text((0, 0), message, "black", font=font)
    assert_image_equal_tofile(im, "Tests/images/test_draw_pbm_target.png")


def test_to_imagefont() -> None:
    with open(fontname, "rb") as test_file:
        pcffont = PcfFontFile.PcfFontFile(test_file)
    imagefont = pcffont.to_imagefont()
    im = Image.new("L", (130, 30), "white")
    draw = ImageDraw.Draw(im)
    draw.text((0, 0), message, "black", font=imagefont)
    assert_image_equal_tofile(im, "Tests/images/test_draw_pbm_target.png")


def test_textsize(request: pytest.FixtureRequest, tmp_path: Path) -> None:
    tempname = save_font(request, tmp_path)
    font = ImageFont.load(tempname)
    for i in range(255):
        ox, oy, dx, dy = font.getbbox(chr(i))
        assert ox == 0
        assert oy == 0
        assert dy == 20
        assert dx in (0, 10)
        assert font.getlength(chr(i)) == dx
    for i in range(len(message)):
        msg = message[: i + 1]
        assert font.getlength(msg) == len(msg) * 10
        assert font.getbbox(msg) == (0, 0, len(msg) * 10, 20)


def _test_high_characters(
    request: pytest.FixtureRequest, tmp_path: Path, message: AnyStr
) -> None:
    tempname = save_font(request, tmp_path)
    font = ImageFont.load(tempname)
    im = Image.new("L", (750, 30), "white")
    draw = ImageDraw.Draw(im)
    draw.text((0, 0), message, "black", font=font)
    assert_image_equal_tofile(im, "Tests/images/high_ascii_chars.png")


def test_high_characters(request: pytest.FixtureRequest, tmp_path: Path) -> None:
    message = "".join(chr(i + 1) for i in range(140, 232))
    _test_high_characters(request, tmp_path, message)
    # accept bytes instances.
    _test_high_characters(request, tmp_path, message.encode("latin1"))


def test_decompression_bomb() -> None:
    with open(fontname, "rb") as fp:
        data = fp.read()
    b = BytesIO(
        data[:900]
        + _binary.o32le(0)  # jumbo format
        + _binary.o32le(1)  # number of metrics
        + _binary.o16le(0)  # left
        + _binary.o16le(65535)  # right
        + _binary.o16le(0)  # width
        + _binary.o16le(0)  # ascent
        + _binary.o16le(65535)  # descent
        + _binary.o16le(0)  # attributes
    )
    with pytest.raises(Image.DecompressionBombError):
        PcfFontFile.PcfFontFile(b)
