# -*- coding: utf-8 -*-
#
# Author: oldj
# Email: oldj.wu@gmail.com
# Blog: http://oldj.net
#

import os
import re
import StringIO
from PIL import Image
from PIL import ImageDraw
import pygame

g_script_folder = os.path.dirname(os.path.abspath(__file__))
g_fonts_folder = os.path.join(g_script_folder, "fonts")

g_re_first_word = re.compile((u""
    + u"(%(prefix)s+\S%(postfix)s+)" # 标点
    + u"|(%(prefix)s*\w+%(postfix)s*)" # 单词
    + u"|(%(prefix)s+\S)|(\S%(postfix)s+)" # 标点
    + u"|(\d+%%)" # 百分数
    ) % {
    "prefix": u"['\"\(<\[\{‘“（《「『]",
    "postfix": u"[:'\"\)>\]\}：’”）》」』,;\.\?!，、；。？！]",
})

pygame.init()

def getFontForPyGame(font_name="wqy-zenhei.ttc", font_size=14):

    return pygame.font.Font(os.path.join(g_fonts_folder, font_name), font_size)


def makeConfig(cfg=None):

    if not cfg or type(cfg) != dict:
        cfg = {}

    default_cfg = {
        "width": 440, # px
        "padding": (15, 18, 20, 18),
        "line-height": 20, #px
        "title-line-height": 32, #px
        "font-size": 14, # px
        "title-font-size": 24, # px
        "font-family": "wqy-zenhei.ttc",
#        "font-family": "msyh.ttf",
        "font-color": (0, 0, 0),
        "font-antialiasing": True, # 字体是否反锯齿
        "background-color": (255, 255, 255),
        "border-size": 1,
        "border-color": (192, 192, 192),
        "copyright": u"本图文由 txt2.im 自动生成，但不代表 txt2.im 赞同其内容或立场。",
        "copyright-center": False, # 版权信息居中显示，如为 False 则居左显示
        "first-line-as-title": True,
        "break-word": False,
    }

    default_cfg.update(cfg)

    return default_cfg


def makeLineToWordsList(line, break_word=False):
    u"""将一行文本转为单词列表"""

    if break_word:
        return [c for c in line]

    lst = []
    while line:
        ro = g_re_first_word.match(line)
        end = 1 if not ro else ro.end()
        lst.append(line[:end])
        line = line[end:]

    return lst


def makeLongLineToLines(long_line, start_x, start_y, width, line_height, font, cn_char_width=0):
    u"""将一个长行分成多个可显示的短行"""

    txt = long_line
#    txt = u"测试汉字abc123"
#    txt = txt.decode("utf-8")

    if not txt:
        return [None]

    words = makeLineToWordsList(txt)
    lines = []

    if not cn_char_width:
        cn_char_width, h = font.size(u"汉")
    avg_char_per_line = width / cn_char_width
    if avg_char_per_line <= 1:
        avg_char_per_line = 1

    line_x = start_x
    line_y = start_y

    while words:

        tmp_words = words[:avg_char_per_line]
        tmp_ln = "".join(tmp_words)
        w, h = font.size(tmp_ln)
        wc = len(tmp_words)
        while w < width and wc < len(words):
            wc += 1
            tmp_words = words[:wc]
            tmp_ln = "".join(tmp_words)
            w, h = font.size(tmp_ln)
        while w > width and len(tmp_words) > 1:
            tmp_words = tmp_words[:-1]
            tmp_ln = "".join(tmp_words)
            w, h = font.size(tmp_ln)
            
        if w > width and len(tmp_words) == 1:
            # 处理一个长单词或长数字
            line_y = makeLongWordToLines(
                tmp_words[0], line_x, line_y, width, line_height, font, lines
            )
            words = words[len(tmp_words):]
            continue

        line = {
            "x": line_x,
            "y": line_y,
            "text": tmp_ln,
            "font": font,
        }

        line_y += line_height
        words = words[len(tmp_words):]

        lines.append(line)

        if len(lines) >= 1:
            # 去掉长行的第二行开始的行首的空白字符
            while len(words) > 0 and not words[0].strip():
                words = words[1:]

    return lines


def makeLongWordToLines(long_word, line_x, line_y, width, line_height, font, lines):

    if not long_word:
        return line_y

    c = long_word[0]
    char_width, char_height = font.size(c)
    default_char_num_per_line = width / char_width

    while long_word:

        tmp_ln = long_word[:default_char_num_per_line]
        w, h = font.size(tmp_ln)
        
        l = len(tmp_ln)
        while w < width and l < len(long_word):
            l += 1
            tmp_ln = long_word[:l]
            w, h = font.size(tmp_ln)
        while w > width and len(tmp_ln) > 1:
            tmp_ln = tmp_ln[:-1]
            w, h = font.size(tmp_ln)

        l = len(tmp_ln)
        long_word = long_word[l:]

        line = {
            "x": line_x,
            "y": line_y,
            "text": tmp_ln,
            "font": font,
            }

        line_y += line_height
        lines.append(line)
        
    return line_y


def makeMatrix(txt, font, title_font, cfg):

    width = cfg["width"]

    data = {
        "width": width,
        "height": 0,
        "lines": [],
    }

    a = txt.split("\n")
    cur_x = cfg["padding"][3]
    cur_y = cfg["padding"][0]
    cn_char_width, h = font.size(u"汉")

    for ln_idx, ln in enumerate(a):
        ln = ln.rstrip()
        if ln_idx == 0 and cfg["first-line-as-title"]:
            f = title_font
            line_height = cfg["title-line-height"]
        else:
            f = font
            line_height = cfg["line-height"]
        current_width = width - cur_x - cfg["padding"][1]
        lines = makeLongLineToLines(ln, cur_x, cur_y, current_width, line_height, f, cn_char_width=cn_char_width)
        cur_y += line_height * len(lines)

        data["lines"].extend(lines)

    data["height"] = cur_y + cfg["padding"][2]

    return data


def makeImage(data, cfg):
    u"""
    """

    width, height = data["width"], data["height"]
    if cfg["copyright"]:
        height += 48
    im = Image.new("RGB", (width, height), cfg["background-color"])
    dr = ImageDraw.Draw(im)

    for ln_idx, line in enumerate(data["lines"]):
        __makeLine(im, line, cfg)
#        dr.text((line["x"], line["y"]), line["text"], font=font, fill=cfg["font-color"])

    # 缩放
#    im = im.resize((width / 2, height / 2), Image.ANTIALIAS)

    drawBorder(im, dr, cfg)
    drawCopyright(im, dr, cfg)

    return im


def drawCopyright(im, dr, cfg):
    u"""绘制版权信息"""

    if not cfg["copyright"]:
        return

    font = getFontForPyGame(font_name=cfg["font-family"], font_size=12)
    rtext = font.render(cfg["copyright"],
        cfg["font-antialiasing"], (128, 128, 128), cfg["background-color"]
    )
    sio = StringIO.StringIO()
    pygame.image.save(rtext, sio)
    sio.seek(0)
    copyright_im = Image.open(sio)

    iw, ih = im.size
    cw, ch = rtext.get_size()
    padding = cfg["padding"]

    offset_y = ih - 32 - padding[2]
    if cfg["copyright-center"]:
        cx = (iw - cw) / 2
    else:
        cx = cfg["padding"][3]
    cy = offset_y + 12

    dr.line([(padding[3], offset_y), (iw - padding[1], offset_y)], width=1, fill=(192, 192, 192))
    im.paste(copyright_im, (cx, cy))


def drawBorder(im, dr, cfg):
    u"""绘制边框"""

    if not cfg["border-size"]:
        return

    w, h = im.size
    x, y = w - 1, h - 1
    dr.line(
        [(0, 0), (x, 0), (x, y), (0, y), (0, 0)],
        width=cfg["border-size"],
        fill=cfg["border-color"],
    )


def __makeLine(im, line, cfg):

    if not line:
        return

    sio = StringIO.StringIO()
    x, y = line["x"], line["y"]
    text = line["text"]
    font = line["font"]
    rtext = font.render(text, cfg["font-antialiasing"], cfg["font-color"], cfg["background-color"])
    pygame.image.save(rtext, sio)

    sio.seek(0)
    ln_im = Image.open(sio)

    im.paste(ln_im, (x, y))


def txt2im(txt, outfn, cfg=None, show=False):

#    print(cfg)
    cfg = makeConfig(cfg)
#    print(cfg)
    font = getFontForPyGame(cfg["font-family"], cfg["font-size"])
    title_font = getFontForPyGame(cfg["font-family"], cfg["title-font-size"])
    data = makeMatrix(txt, font, title_font, cfg)
    im = makeImage(data, cfg)
    im.save(outfn)
    if os.name == "nt" and show:
        im.show()


def test():

    c = open("test.txt", "rb").read().decode("utf-8")
    txt2im(c, "test.png", show=True)


if __name__ == "__main__":
    test()