#!/usr/bin/env python3

import re
import os
import pwd
import subprocess
from subprocess import PIPE
import hashlib
import os.path as path
from os.path import dirname
import email
from email.policy import default
from datetime import datetime
from dateutil import parser as dtparser
import argparse
import sys
import shutil

path_base = '/'

global_bilaga = 0

self_prog = os.path.realpath(sys.argv[0])

def anglify(str):
    table = {
            'å': 'a',
            'ä': 'a',
            'ö': 'o',
            }
    return ''.join(table.get(c, c) for c in str)

# ------------------------------------------------------------

def includepdf(mode, addr, full_file):
    if mode == 'tex':
        arg = 'frame'
        arg += ',pages={-}'
        pagecommand = '\\thispagestyle{fancy}'
        arg += f',pagecommand={{{pagecommand}}}'
        arg += ',width=\\textwidth'
        before = f'\\rhead{{Bilaga \\Alph{{section}}.\\arabic{{subsection}} {texify_filename(addr)} }}\n'
        before += f'\\phantomsection\\stepcounter{{subsection}}\n'
        before += f'\\includepdf[{arg}]{{\\detokenize{{{full_file}}}}}\n'
        return before
    elif mode == 'txt':
        return f"Se pdf {addr}\n"

def includeimg(mode, addr, full_file):
    if mode == 'tex':
        pagecommand = '\\thispagestyle{fancy}'
        pagecommand += f'\\lhead{{Bilaga \\Alph{{section}}.\\arabic{{subsection}} {texify_filename(addr)} }}'
        arg = 'width=\\textwidth'
        return f'\\phantomsection\\stepcounter{{subsection}}\n\\includegraphics[{arg}]{{{full_file}}}\n'
    elif mode == 'txt':
        return f"Se bild {addr}\n"


def shorten_mail(str):
    last_arrow = False
    out = []
    for line in str.split('\n'):
        if not line:
            out += ['']
            continue
        if line[0] == '>':
            arrow = True
            if arrow and not last_arrow:
                out += ['> [...]']
            last_arrow = True
            continue
        out += [line]
    return '\n'.join(out)


def texify_filename(str):
    out = ''
    for c in str:
        if c == '_':
            out += '\\_'
        else:
            out += c

    return out

def split_into_paragraphs(str):
    lines = str.split('\n')
    paragraphs = []
    paragraph = []
    for line in lines:
        if line == '':
            if paragraph == []:
                continue
            else:
                paragraphs.append(paragraph)
                paragraph = []
        else:
            paragraph.append(line)
    return paragraphs

def parse_options_paragraph(paragraphs):
    """
    check the first paragraph for a definition list, and parse that
    into variables
    """

    options = {}

    for i in range(len(paragraphs[0])):
        line = paragraphs[0][i]
        if m := re.match('^(\w+)\s*::\s*(.*)', line):
            options[m[1]] = m[2]
        else:
            # remove handled lines, keep remaining lines in paragraphs list
            paragraphs[0] = paragraphs[0][i:]
            break
    else:
        # remove first paragraph from paragraphs list
        paragraphs = paragraphs[1:]

    return options, paragraphs


def resolve_mail(mode, source_file_name, addr, frag, comment):

    outstr = ''

    msg_id = addr
    mailfile = subprocess.run(f"mu find -u 'i:{msg_id}' --fields 'l'", shell=True, stdout=PIPE).stdout.decode('UTF-8').strip()
    # mail = subprocess.run(f"mu view {mailfile}", shell=True, stdout=PIPE).stdout.decode('UTF-8')

    with open(mailfile, 'rb') as f:
        msg = email.message_from_binary_file(f, policy=default)

    if not frag == 'attachments-only':
        if mode == 'tex':
            outstr += '\\begin{verbatim}\n'

        # mail += msg.get_content_type() + '\n'

        body = msg.get_body(preferencelist=('plain', 'html'))
        for field in ['Date', 'From', 'To' 'Cc', 'Subject']:
            h = msg.get(field)
            if h: outstr += f'{field}: {h}\n'
        outstr += '\n'
        if frag == 'short':
            outstr += shorten_mail(body.get_content())
        else:
            outstr += body.get_content()
        if mode == 'tex':
            outstr += '\\end{verbatim}\n'

    # TODO merge this logic with the resolve file logic below
    for part in msg.iter_attachments():
        if part.get_content_type() == 'application/pdf' or part.get_content_type().split('/')[0] == 'image':
            safe_filename = part.get_filename() \
                    .replace('/', '_') \
                    .replace('å', 'a') \
                    .replace('ä', 'a') \
                    .replace('ö', 'o')
            with open('/tmp/' + safe_filename, 'wb') as f:
                f.write(part.get_content())
            # outstr += part.get_filename() + '\n'
            if part.get_content_type() == 'application/pdf':
                outstr += includepdf(mode, safe_filename, '/tmp/' + safe_filename)
            else:
                outstr += includeimg(mode, safe_filename, '/tmp/' + safe_filename)
        else:
            if mode == 'tex':
                outstr += f'\\subsection{{{texify_filename(part.get_filename())}}}\n'
            elif mode == 'txt':
                global subsectioncounter
                subsectioncounter += 1
                outstr += f'  {sectioncounter}.{subsectioncounter}. {part.get_filename()}\n'
            content = part.get_content()
            if type(content) == bytes:
                content = content.decode('utf-8')
            if max(len(s) for s in content.split('\n')) > 100:
                # outstr += '\\setlength\\parindent{24pt}'
                outstr += content + '\n'
            else:
                if mode == 'tex':
                    outstr += '\n\\begin{verbatim}'
                outstr += content + '\n'
                if mode == 'tex':
                    outstr += '\\end{verbatim}'
        # mail += f'{part.get_content_type()} - {part.get_filename()}\n'

    # for part in msg.walk():
    #     mail += f'{part.get_content_type()} - {part.get_filename()}\n'

    # for part in msg.walk():
    #for part in msg.walk():
    #    if part.get_content_maintype() == 'multipart':
    #        continue
    #    mail += f'== {part.get_content_type()} ==\n\n'
    #    if part.get_content_type() == 'application/pdf':
    #        mail += part.get_filename() + '\n\n'
    #    else:
    #        mail += part.as_string(policy=default)

    # mail = msg.as_string()

    return outstr


def resolve_help(mode, source_file_name, addr, frag, comment):
    pass
    return ''


def resolve_file(mode, source_file_name, addr, frag, comment):
    extension = addr.split('.')[-1]

    full_file = path.join(path_base, addr)

    if extension == 'pdf':
        s = ''
        if mode == 'tex':
            s += '\\stepcounter{section}\n'
            s += '\\phantomsection\n'
        # TODO header for txt mode?
        # s += f'\\addcontentsline{{toc}}{{chapter}}{{{texify_filename(addr)}}}\n'
        # s = f'\\includepdf[pages={{1}},width=\\textwidth]{{{full_file}}}\n'
        s += includepdf(mode, addr, full_file)
        return s
    elif extension.lower() in ['jpg', 'jpeg', 'png', 'gif']:
        return includeimg(mode, addr, full_file)
    # TODO
    # elif extension == 'tex':
    #     return f'\\subfile{{{full_file}}}\n'
    else:
        print('PWD =', os.getcwd(), full_file)
        with open(full_file, 'r') as f:
            s = f.read() + '\n'
        if mode == 'tex':
            st = f'\\section{{{comment}}}'
            st += r'\begin{verbatim}' + s + r'\end{verbatim}' + '\n'
            return st
        else:
            return s


def generate_attachement(mode, data):
    outstr = ''
    opts, paragraphs = parse_options_paragraph(split_into_paragraphs(data))
    options = {
            'mode': 'verbatim',
            **opts
            }

    if mode == 'tex':
        if options['mode'] == 'tex':
            pass
        else:
            outstr += '\\begin{verbatim}\n'
    for paragraph in paragraphs:
        outstr += '\n'.join(paragraph)
        outstr += '\n\n'
    if mode == 'tex':
        if options['mode'] == 'tex':
            pass
        else:
            outstr += '\\end{verbatim}\n'

    return outstr

def resolve_vimwiki(mode, source_file_name, addr, frag, comment):
    here = os.getcwd()
    print('Resolving vimwiki')
    fname = anglify(f'/tmp/{addr}-{frag}.{mode}')
    cmd = subprocess.run([self_prog,
        '--mode', mode,
        '--output', fname,
        '--attach-prefix', f'{global_bilaga}',
        f'{here}/{addr}.wiki', frag])
    if cmd.returncode != 0:
        print(f'Recursive call failed with {cmd.returncode}')
    if mode == 'tex':
        try:
            os.chdir(os.path.dirname(fname));
            cmd = subprocess.run(['latexmk', '-lualatex', fname])
            print(f'latexmk failed with {cmd.returncode}')
        finally:
            os.chdir(here)
        ofile = anglify(f'/tmp/{addr}-{frag}.pdf')
    else:
        ofile = fname

    return resolve_file(mode, source_file_name, ofile, '', comment)

def resolve_default(mode, source_file_name, addr, frag, comment):
    outstr = ''
    if addr == '':
        outstr = generate_attachement(mode, get_heading(frag, data))
    else:
        with open('{}/{}.wiki'.format(dirname(source_file_name), addr)) as f:
            dat = f.read()
        if frag == '':
            outstr = dat
        else:
            outstr = generate_attachement(mode, get_heading(frag, dat))
            # print(addr)
            # print("Vimwiki intra-page links not yet supported")
            # outstr = ''
    return outstr

# Should all take (mode string, url without protocol, fragment, comment)
# and return the complete text of the attachement, formatted according
# to mode
resolvers = {
        'mail': resolve_mail,
        'file': resolve_file,
        'local': resolve_file,
        'help': resolve_help,
        'vimwiki': resolve_vimwiki,
}

# ------------------------------------------------------------

# TODO handle case where heading is missing
def get_heading(name, data):
    print('data =', data)
    print('name =', name)
    start_match = re.search(f'(?m)^(=+) {name} =+$', data)
    print('start_match =', start_match)
    heading_level = len(start_match.group(1))
    print(start_match.end())
    tail = data[start_match.end():]
    pat = f'(?m)^(={{1,{heading_level}}} .*|---*)$'
    print(pat)
    end_match = re.search(pat, tail)
    print(end_match)
    if end_match:
        return tail[:end_match.start() - 1]
    else:
        return tail

# ------------------------------------------------------------

def renumber_wiki_headings(text):
    # Re-level all headings
    longest = 0
    shortest = 1000
    for m in re.finditer(r'(?m)^ *(=+).*=+ *$', text):
        longest = max(longest, len(m[1]))
        shortest = min(shortest, len(m[1]))
    for length in range(longest, shortest + 1):
        text = re.sub('=' * length, '=' * (length - shortest + 1), text)
    return text

def format_wikitext(output, mode, paragraphs):
    if mode == 'txt':
        for paragraph in paragraphs:
            output.write('\n'.join(paragraph))
            output.write('\n\n')
    elif mode == 'tex':
        if shutil.which('pandoc'):
            wiki_file = '/tmp/file.vimwiki'
            tex_file = '/tmp/file.tex'

            text = '\n\n'.join('\n'.join(par) for par in paragraphs) + '\n\n'
            full_text = renumber_wiki_headings(text)

            with open(wiki_file, 'w') as f:
                f.write(full_text)
            cmd = subprocess.run(['pandoc', '-f', 'vimwiki', '-t', 'latex', '-o', tex_file, wiki_file])
            with open(tex_file) as f:
                for line in f:
                    output.write(line)

        else: # no pandoc
            if options['mode'] == 'tex':
                pass
            else:
                output.write('\\begin{verbatim}\n')

            for paragraph in paragraphs:
                output.write('\n'.join(paragraph))
                output.write('\n\n')

            if options['mode'] == 'tex':
                pass
            else:
                output.write('\\end{verbatim}\n')


def main():
    global path_base

    parser = argparse.ArgumentParser(
            description='parse vimwiki files',
            formatter_class=argparse.ArgumentDefaultsHelpFormatter)
    parser.add_argument('--mode', choices=["tex", "txt"],
            default='txt', help="Format of output")
    parser.add_argument('--output')
    parser.add_argument('--attach-prefix', dest='attach_prefix')
    parser.add_argument('infile', help="Wiki-file to use for input")
    parser.add_argument('heading', help="Which heading to output")
    args = parser.parse_args()


    if pre := args.attach_prefix:
        attach_prefix = f'{pre}.'
    else:
        attach_prefix = ''


    mode = args.mode

    infile = args.infile
    heading = args.heading

    print(f'Running on {infile} # [{heading}]')

    outfile = os.path.realpath(args.output or f'doc.{mode}')
    print(f'outfile = {outfile}')

    os.chdir(os.path.dirname(infile))

    file = open(infile, 'r')
    data = file.read()

    path_base = path.dirname(infile)


    try:
        os.mkdir(os.path.dirname(outfile))
    except FileExistsError:
        pass
    output = open(outfile, 'w')



    if mode == 'tex':
        output.write(r'''
\PassOptionsToPackage{unicode}{hyperref}
\PassOptionsToPackage{hyphens}{url}

\documentclass[a4paper]{article}

\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[swedish]{babel}
\usepackage{verbatim}
\usepackage{fullpage}
\usepackage{pdfpages}
\usepackage{subfiles}
\usepackage{parskip}
\usepackage{fancyhdr}
\usepackage{hyperref}
\usepackage{soul}
\usepackage{graphics}
\usepackage{amsmath,amssymb}
\usepackage{lmodern}
\usepackage{iftex}
\usepackage{xcolor}
\providecommand{\tightlist}{\setlength{\itemsep}{0pt}\setlength{\parskip}{0pt}}
        ''')

    elif mode == 'txt':
        sectioncounter = 0
        subsectioncounter = 0

    # '\\verbatiminput

    page1 = get_heading(heading, data)
    # bilagor = get_heading('Bilagor', page1).strip().split('\n')

    # Find all links
    r = r"\[\[([^|#\]]*)(?:#([^|\]]*))?(?:[|]([^\]]*))?\]\]"
    # bilagor = re.findall(r, page1)
    tag_iter = re.finditer(r, page1)

    # bilagor = [m[0] for m in re.findall(r, data)]

    bilagor = []

    outstr = ""
    pos = 0

    # Resolve all links
    bilaga_nr = 1
    global_bilaga = bilaga_nr
    for match in tag_iter:
        url = match.group(1) or ''
        frag = match.group(2) or ''
        comment = match.group(3) or ''

        outstr += page1[pos:match.start()]
        pos = match.end()

        uid = hashlib.md5((url + frag).encode('UTF-8')).hexdigest()

        title = comment or url or frag

        try:
            proto, addr = url.split(":", 1)
        except ValueError:
            proto = 'vimwiki'
            addr = url
        print('proto, addr =', proto, addr)

        if proto in ['http', 'https']:
            url = f'{proto}:{addr}'
            if frag:
                url += f'#{frag}'
            if mode == 'tex':
                # outstr += f" \\href{{{url}}}{{{title} \\nolinkurl{{{url}}}}}"
                outstr += f'[[{url}|{title}]] [[{url}|{url}]])'
            else:
                outstr += f' {title} <{url}>'
            continue

        # outstr += title + f"(bilaga~\\ref{{{uid}}})"
        # TODO
        outstr += title + f' (bilaga {attach_prefix}{chr(bilaga_nr + 64)})'
        # outstr += title + " (se bilaga)"
        bilaga_nr += 1
        global_bilaga = bilaga_nr


        # disabled for full PDF:s
        attach_str = ''
        if mode == 'tex':
            if proto not in ['file', 'local', 'vimwiki']:
                attach_str += f"\\section{{{title}}}\n\\label{{{uid}}}\n"
            else:
                attach_str += f"\\phantomsection\n\\label{{{uid}}}\n"
        elif mode == 'txt':
            sectioncounter += 1
            subsectioncounter = 0
            if proto not in ['file', 'local']:
                st = f"{attach_prefix}{chr(sectioncounter + 64)}. {title}"
                attach_str += f'\n{st}\n{"="*len(st)}\n'

        resolver = resolvers.get(proto, resolve_default)
        attach_str += resolver(mode, infile, addr, frag, comment)
        bilagor += [attach_str]


    outstr += page1[pos:]

    options = {
            'date': '\\today' if mode == 'tex' else f'{datetime.now():%Y-%m-%d}',
            'mode': 'vimwiki',
            'author': pwd.getpwuid(os.getuid()).pw_gecos
            }

    # split the text into paragraph blocks
    paragraphs = split_into_paragraphs(outstr)

    override_options, paragraphs = parse_options_paragraph(paragraphs)

    # Merge found options with default options
    for key, value in override_options.items():
        # Parse and recard date option
        if key == 'date':
            dt = dtparser.parse(value)
            if mode == 'tex':
                options['date'] = f'{dt:%Y--%m--%d}'
            else:
                options['date'] = f'{dt:%Y-%m-%d}'
        else:
            options[key] = value



    # Preamble
    if mode == 'tex':
        output.write(f"""
\\title{{{heading}}}
\\date{{{options['date']}}}
\\author{{{options['author']}}}
\\begin{{document}}
\\maketitle
% \\tableofcontents
        """)
    elif mode == 'txt':
        d = options['date']
        output.write(f'\n{heading.center(40)}\n{d.center(40)}\n')

    format_wikitext(output, mode, paragraphs)

    # Postamble
    if mode == 'tex':
        output.write('\\appendix\n')

    output.write('\n'.join(bilagor))

    if mode == 'tex':
        output.write('\\end{document}')



if __name__ == '__main__':
    main()