#!/usr/bin/env python2
# vim:fileencoding=utf-8
from __future__ import (unicode_literals, division, absolute_import,
                        print_function)

__license__ = 'GPL v3'
__copyright__ = '2015, Kovid Goyal <kovid at kovidgoyal.net>'

import re, struct, ctypes
from collections import namedtuple
from future_builtins import map

from PyQt5.Qt import QtWin, Qt, QIcon, QByteArray, QBuffer, QPixmap
import win32con, win32api, win32gui, pywintypes, winerror

from calibre import prints
from calibre.gui2 import must_use_qt
from calibre.utils.winreg.default_programs import split_commandline

ICON_SIZE = 64

def hicon_to_pixmap(hicon):
    return QtWin.fromHICON(hicon)

def pixmap_to_data(pixmap):
    ba = QByteArray()
    buf = QBuffer(ba)
    buf.open(QBuffer.WriteOnly)
    pixmap.save(buf, 'PNG')
    return bytearray(ba.data())

def copy_to_size(pixmap, size=ICON_SIZE):
    if pixmap.width() > ICON_SIZE:
        return pixmap.scaled(ICON_SIZE, ICON_SIZE, transformMode=Qt.SmoothTransformation)
    return pixmap.copy()

def simple_load_icon(module, index, as_data=False, size=ICON_SIZE):
    ' Use the win32 API ExtractIcon to load the icon. This restricts icon size to 32x32, but has less chance of failing '
    try:
        large_icons, small_icons = win32gui.ExtractIconEx(module, index, 10)
    except pywintypes.error as err:
        if err.winerror != winerror.ERROR_FILE_NOT_FOUND:
            raise
        prints('File %r does not exist, cannot load icon' % module)
        return
    icons = large_icons + small_icons
    try:
        if icons:
            must_use_qt()
            pixmap = copy_to_size(QtWin.fromHICON(icons[0]), size=size)
            if as_data:
                return pixmap_to_data(pixmap)
            return QIcon(pixmap)
    finally:
        tuple(map(win32gui.DestroyIcon, icons))


def read_icon(handle, icon):
    must_use_qt()
    resource = win32api.LoadResource(handle, win32con.RT_ICON, icon.id)
    pixmap = QPixmap()
    pixmap.loadFromData(resource)
    hicon = None
    if pixmap.isNull():
        if icon.width > 0 and icon.height > 0:
            hicon = ctypes.windll.user32.CreateIconFromResourceEx(
                resource, len(resource), True, 0x00030000, icon.width, icon.height, win32con.LR_DEFAULTCOLOR)
        else:
            hicon = win32gui.CreateIconFromResource(resource, True)
        pixmap = hicon_to_pixmap(hicon).copy()
        win32gui.DestroyIcon(hicon)
    return pixmap


def load_icon(module, index, as_data=False, size=ICON_SIZE):
    handle = win32api.LoadLibraryEx(module, 0, 0x20 | 0x2)
    try:
        ids = win32api.EnumResourceNames(handle, win32con.RT_GROUP_ICON)
        grp_id = -index if index < 0 else ids[index]
        data = win32api.LoadResource(handle, win32con.RT_GROUP_ICON, grp_id)
        pos = 0
        reserved, idtype, count = struct.unpack_from(b'<HHH', data, pos)
        pos += 6
        fmt = b'<BBBBHHIH'
        ssz = struct.calcsize(fmt)
        icons = []
        Icon = namedtuple('Icon', 'size width height id')
        while count > 0:
            count -= 1
            width, height, color_count, reserved, planes, bitcount, isize, icon_id = struct.unpack_from(fmt, data, pos)
            icons.append(Icon(isize, width, height, icon_id))
            pos += ssz
        # Unfortunately we cannot simply choose the icon with the largest
        # width/height as the width and height are not recorded for PNG images
        pixmaps = []
        for icon in icons:
            ans = read_icon(handle, icon)
            if ans is not None and not ans.isNull():
                pixmaps.append(ans)
        pixmaps.sort(key=lambda p:p.size().width(), reverse=True)
        pixmap = copy_to_size(pixmaps[0], size=size)
        if as_data:
            pixmap = pixmap_to_data(pixmap)
        return pixmap
    finally:
        win32api.FreeLibrary(handle)

def load_icon_resource(icon_resource, as_data=False, size=ICON_SIZE):
    if not icon_resource:
        return
    parts = tuple(filter(None, re.split(r',([-0-9]+$)', icon_resource)))
    if len(parts) != 2:
        return
    module, index = parts
    index = int(index)
    if module.startswith('"') and module.endswith('"'):
        module = split_commandline(module)[0]
    try:
        return load_icon(module, index, as_data=as_data, size=size)
    except Exception:
        return simple_load_icon(module, index, as_data=as_data, size=size)
