import markdown
import re
import os
import math
from textwrap import dedent
from functools import lru_cache
from pymdownx.superfences import fence_code_format
from latex2mathml.converter import convert as tex2mathml
from shared_utils.config_loader import get_conf as get_conf
from shared_utils.text_mask import apply_gpt_academic_string_mask

markdown_extension_configs = {
    "mdx_math": {
        "enable_dollar_delimiter": True,
        "use_gitlab_delimiters": False,
    },
}

code_highlight_configs = {
    "pymdownx.superfences": {
        "css_class": "codehilite",
        "custom_fences": [
            {"name": "mermaid", "class": "mermaid", "format": fence_code_format}
        ],
    },
    "pymdownx.highlight": {
        "css_class": "codehilite",
        "guess_lang": True,
        # 'auto_title': True,
        # 'linenums': True
    },
}


def text_divide_paragraph(text):
    """
    将文本按照段落分隔符分割开，生成带有段落标签的HTML代码。
    """
    pre = '<div class="markdown-body">'
    suf = "</div>"
    if text.startswith(pre) and text.endswith(suf):
        return text

    if "```" in text:
        # careful input
        return text
    elif "</div>" in text:
        # careful input
        return text
    else:
        # whatever input
        lines = text.split("\n")
        for i, line in enumerate(lines):
            lines[i] = lines[i].replace(" ", "&nbsp;")
        text = "</br>".join(lines)
        return pre + text + suf


def tex2mathml_catch_exception(content, *args, **kwargs):
    try:
        content = tex2mathml(content, *args, **kwargs)
    except:
        content = content
    return content


def replace_math_no_render(match):
    content = match.group(1)
    if "mode=display" in match.group(0):
        content = content.replace("\n", "</br>")
        return f'<font color="#00FF00">$$</font><font color="#FF00FF">{content}</font><font color="#00FF00">$$</font>'
    else:
        return f'<font color="#00FF00">$</font><font color="#FF00FF">{content}</font><font color="#00FF00">$</font>'


def replace_math_render(match):
    content = match.group(1)
    if "mode=display" in match.group(0):
        if "\\begin{aligned}" in content:
            content = content.replace("\\begin{aligned}", "\\begin{array}")
            content = content.replace("\\end{aligned}", "\\end{array}")
            content = content.replace("&", " ")
        content = tex2mathml_catch_exception(content, display="block")
        return content
    else:
        return tex2mathml_catch_exception(content)


def markdown_bug_hunt(content):
    """
    解决一个mdx_math的bug（单$包裹begin命令时多余<script>）
    """
    content = content.replace(
        '<script type="math/tex">\n<script type="math/tex; mode=display">',
        '<script type="math/tex; mode=display">',
    )
    content = content.replace("</script>\n</script>", "</script>")
    return content


def is_equation(txt):
    """
    判定是否为公式 | 测试1 写出洛伦兹定律，使用tex格式公式 测试2 给出柯西不等式，使用latex格式 测试3 写出麦克斯韦方程组
    """
    if "```" in txt and "```reference" not in txt:
        return False
    if "$" not in txt and "\\[" not in txt:
        return False
    mathpatterns = {
        r"(?<!\\|\$)(\$)([^\$]+)(\$)": {"allow_multi_lines": False},  #  $...$
        r"(?<!\\)(\$\$)([^\$]+)(\$\$)": {"allow_multi_lines": True},  # $$...$$
        r"(?<!\\)(\\\[)(.+?)(\\\])": {"allow_multi_lines": False},  # \[...\]
        # r'(?<!\\)(\\\()(.+?)(\\\))': {'allow_multi_lines': False},                       # \(...\)
        # r'(?<!\\)(\\begin{([a-z]+?\*?)})(.+?)(\\end{\2})': {'allow_multi_lines': True},  # \begin...\end
        # r'(?<!\\)(\$`)([^`]+)(`\$)': {'allow_multi_lines': False},                       # $`...`$
    }
    matches = []
    for pattern, property in mathpatterns.items():
        flags = re.ASCII | re.DOTALL if property["allow_multi_lines"] else re.ASCII
        matches.extend(re.findall(pattern, txt, flags))
    if len(matches) == 0:
        return False
    contain_any_eq = False
    illegal_pattern = re.compile(r"[^\x00-\x7F]|echo")
    for match in matches:
        if len(match) != 3:
            return False
        eq_canidate = match[1]
        if illegal_pattern.search(eq_canidate):
            return False
        else:
            contain_any_eq = True
    return contain_any_eq


def fix_markdown_indent(txt):
    # fix markdown indent
    if (" - " not in txt) or (". " not in txt):
        # do not need to fix, fast escape
        return txt
    # walk through the lines and fix non-standard indentation
    lines = txt.split("\n")
    pattern = re.compile(r"^\s+-")
    activated = False
    for i, line in enumerate(lines):
        if line.startswith("- ") or line.startswith("1. "):
            activated = True
        if activated and pattern.match(line):
            stripped_string = line.lstrip()
            num_spaces = len(line) - len(stripped_string)
            if (num_spaces % 4) == 3:
                num_spaces_should_be = math.ceil(num_spaces / 4) * 4
                lines[i] = " " * num_spaces_should_be + stripped_string
    return "\n".join(lines)


FENCED_BLOCK_RE = re.compile(
    dedent(
        r"""
        (?P<fence>^[ \t]*(?:~{3,}|`{3,}))[ ]*                      # opening fence
        ((\{(?P<attrs>[^\}\n]*)\})|                              # (optional {attrs} or
        (\.?(?P<lang>[\w#.+-]*)[ ]*)?                            # optional (.)lang
        (hl_lines=(?P<quot>"|')(?P<hl_lines>.*?)(?P=quot)[ ]*)?) # optional hl_lines)
        \n                                                       # newline (end of opening fence)
        (?P<code>.*?)(?<=\n)                                     # the code block
        (?P=fence)[ ]*$                                          # closing fence
    """
    ),
    re.MULTILINE | re.DOTALL | re.VERBOSE,
)


def get_line_range(re_match_obj, txt):
    start_pos, end_pos = re_match_obj.regs[0]
    num_newlines_before = txt[: start_pos + 1].count("\n")
    line_start = num_newlines_before
    line_end = num_newlines_before + txt[start_pos:end_pos].count("\n") + 1
    return line_start, line_end


def fix_code_segment_indent(txt):
    lines = []
    change_any = False
    txt_tmp = txt
    while True:
        re_match_obj = FENCED_BLOCK_RE.search(txt_tmp)
        if not re_match_obj:
            break
        if len(lines) == 0:
            lines = txt.split("\n")

        # 清空 txt_tmp 对应的位置方便下次搜索
        start_pos, end_pos = re_match_obj.regs[0]
        txt_tmp = txt_tmp[:start_pos] + " " * (end_pos - start_pos) + txt_tmp[end_pos:]
        line_start, line_end = get_line_range(re_match_obj, txt)

        # 获取公共缩进
        shared_indent_cnt = 1e5
        for i in range(line_start, line_end):
            stripped_string = lines[i].lstrip()
            num_spaces = len(lines[i]) - len(stripped_string)
            if num_spaces < shared_indent_cnt:
                shared_indent_cnt = num_spaces

        # 修复缩进
        if (shared_indent_cnt < 1e5) and (shared_indent_cnt % 4) == 3:
            num_spaces_should_be = math.ceil(shared_indent_cnt / 4) * 4
            for i in range(line_start, line_end):
                add_n = num_spaces_should_be - shared_indent_cnt
                lines[i] = " " * add_n + lines[i]
            if not change_any:  # 遇到第一个
                change_any = True

    if change_any:
        return "\n".join(lines)
    else:
        return txt


@lru_cache(maxsize=128)  # 使用 lru缓存 加快转换速度
def markdown_convertion(txt):
    """
    将Markdown格式的文本转换为HTML格式。如果包含数学公式，则先将公式转换为HTML格式。
    """
    pre = '<div class="markdown-body">'
    suf = "</div>"
    if txt.startswith(pre) and txt.endswith(suf):
        # print('警告，输入了已经经过转化的字符串，二次转化可能出问题')
        return txt  # 已经被转化过，不需要再次转化

    find_equation_pattern = r'<script type="math/tex(?:.*?)>(.*?)</script>'

    txt = fix_markdown_indent(txt)
    # txt = fix_code_segment_indent(txt)
    if is_equation(txt):  # 有$标识的公式符号，且没有代码段```的标识
        # convert everything to html format
        split = markdown.markdown(text="---")
        convert_stage_1 = markdown.markdown(
            text=txt,
            extensions=[
                "sane_lists",
                "tables",
                "mdx_math",
                "pymdownx.superfences",
                "pymdownx.highlight",
            ],
            extension_configs={**markdown_extension_configs, **code_highlight_configs},
        )
        convert_stage_1 = markdown_bug_hunt(convert_stage_1)
        # 1. convert to easy-to-copy tex (do not render math)
        convert_stage_2_1, n = re.subn(
            find_equation_pattern,
            replace_math_no_render,
            convert_stage_1,
            flags=re.DOTALL,
        )
        # 2. convert to rendered equation
        convert_stage_2_2, n = re.subn(
            find_equation_pattern, replace_math_render, convert_stage_1, flags=re.DOTALL
        )
        # cat them together
        return pre + convert_stage_2_1 + f"{split}" + convert_stage_2_2 + suf
    else:
        return (
            pre
            + markdown.markdown(
                txt,
                extensions=[
                    "sane_lists",
                    "tables",
                    "pymdownx.superfences",
                    "pymdownx.highlight",
                ],
                extension_configs=code_highlight_configs,
            )
            + suf
        )


def close_up_code_segment_during_stream(gpt_reply):
    """
    在gpt输出代码的中途（输出了前面的```，但还没输出完后面的```），补上后面的```

    Args:
        gpt_reply (str): GPT模型返回的回复字符串。

    Returns:
        str: 返回一个新的字符串，将输出代码片段的“后面的```”补上。

    """
    if "```" not in gpt_reply:
        return gpt_reply
    if gpt_reply.endswith("```"):
        return gpt_reply

    # 排除了以上两个情况，我们
    segments = gpt_reply.split("```")
    n_mark = len(segments) - 1
    if n_mark % 2 == 1:
        return gpt_reply + "\n```"  # 输出代码片段中！
    else:
        return gpt_reply

def simple_markdown_convertion(txt):
    pre = '<div class="markdown-body">'
    suf = "</div>"
    if txt.startswith(pre) and txt.endswith(suf):
        return txt  # 已经被转化过，不需要再次转化
    txt = markdown.markdown(
        txt,
        extensions=["pymdownx.superfences", "tables", "pymdownx.highlight"],
        extension_configs=code_highlight_configs,
    )
    return pre + txt + suf

def format_io(self, y):
    """
    将输入和输出解析为HTML格式。将y中最后一项的输入部分段落化，并将输出部分的Markdown和数学公式转换为HTML格式。
    """
    if y is None or y == []:
        return []
    i_ask, gpt_reply = y[-1]
    i_ask = apply_gpt_academic_string_mask(i_ask, mode="show_render")
    gpt_reply = apply_gpt_academic_string_mask(gpt_reply, mode="show_render")
    # 输入部分太自由，预处理一波
    if i_ask is not None:
        i_ask = text_divide_paragraph(i_ask)
    # 当代码输出半截的时候，试着补上后个```
    if gpt_reply is not None:
        gpt_reply = close_up_code_segment_during_stream(gpt_reply)
    # 处理提问与输出
    y[-1] = (
        # 输入部分
        None if i_ask is None else simple_markdown_convertion(i_ask),
        # 输出部分
        None if gpt_reply is None else markdown_convertion(gpt_reply),
    )
    return y