#!/usr/bin/env python3

# Maintainer: Darks
# Disclaimer: this script has been done as a quick n' dirty way to convert
# markdown to Planète Casio's BBcode. As it, it does support only those
# features:
#  - # H1 title
#  - ## H2 title
#  - ### H3 title
#  - *emphasis text*
#  - **strong text**
#  - [link](https://domain.tld)
#  - {{ tableofcontents }}
#
# More features may be added in the future, but this script is provided as it.


import argparse, re, sys


# Manage arguments
parser = argparse.ArgumentParser(
    description="Convert Markdown to PC's BBcode")
parser.add_argument("input", type=argparse.FileType('r'), help="input file")
args = parser.parse_args()

# Useful regex
r_h1 = re.compile("^# (.+)$", re.I|re.M)
r_h2 = re.compile("^## (.+)$", re.I|re.M)
r_h3 = re.compile("^### (.+)$", re.I|re.M)
r_link = re.compile("(\W)\[(.+?)\]\((.+?)\)(\W)", re.I|re.M)
r_strong = re.compile("(\W|^)\*{2}(\w.+?)\*{2}(\W|$)", re.I|re.M)
r_em = re.compile("(\W|^)\*(\w.+?)\*(\W|$)", re.I|re.M)

# Open and extract document
markdown = args.input.read().splitlines()

# Manage titles
table_of_contents = ""
n_h1 = 0
n_h2 = 0
n_h3 = 0
output = []

# TODO: factorize this pile of shit
for line in markdown:
    if (res := r_h1.search(line)):
        n_h1 += 1
        n_h2 = 0
        n_h3 = 0
        header = res.group(1)
        index = f"{n_h1}"
        label = index.replace(".", "_")
        table_of_contents += f"[target={label}]{index} – {header}[/target]\n"
        output.append(f"[big][brown][b]{index} – {header}[/b][/brown][/big]"
            f"[label={index}]")
    elif (res := r_h2.search(line)):
        n_h2 += 1
        n_h3 = 0
        header = res.group(1)
        index = f"{n_h1}.{n_h2}"
        label = index.replace(".", "_")
        table_of_contents += f"    [target={label}]{index} – {header}[/target]\n"
        output.append(f"[brown][b]{index} – {header}[/b][/brown]"
            f"[label={label}]")
    elif (res := r_h3.search(line)):
        n_h3 += 1
        header = res.group(1)
        index = f"{n_h1}.{n_h2}.{n_h3}"
        label = index.replace(".", "_")
        table_of_contents += f"        [target={label}]{index} – {header}[/target]\n"
        output.append(f"[b]{index} – {header}[/b]"
            f"[label={label}]")
    else:
        res = r_link.sub(
            lambda m: f"{m.group(1)}[url={m.group(3)}]{m.group(2)}[/url]{m.group(4)}", line)
        res = r_strong.sub(
            lambda m: f"{m.group(1)}[b]{m.group(2)}[/b]{m.group(3)}", res)
        res = r_em.sub(
            lambda m: f"{m.group(1)}[i]{m.group(2)}[/i]{m.group(3)}", res)
        output.append(res)

# Add table of content
output = '\n'.join(output)
output = re.sub("{{ tableofcontents }}", table_of_contents, output)

# Print output on stdout
print(output)