#!/usr/bin/env python3

import fnmatch
import hashlib
import json
import os
import shutil
import sqlite3
import sys
import time
import urllib.parse
import argparse

import trac2md

wiki_query = '''
  SELECT
    name, 
    author,
    version, 
    time / 1000000 AS time, 
    text 
  FROM wiki
  ORDER BY
    name, version
'''

attachment_query = '''
  SELECT
    id,
    filename,
    size,
    author,
    description,
    ipnr,
    time / 1000000 AS createdtime
  FROM
    attachment
  WHERE
    type = 'wiki'
  ORDER BY
    filename, time
'''

def attachment_link(row):
    h   = lambda whatever: hashlib.sha1(whatever.encode()).hexdigest()
    h1  = h(row.id)
    h2  = h(row.filename)
    fn2 = os.path.splitext(row["filename"])[1]
    return \
        os.path.join("attachments", "wiki", h1[:3], h1, h2 + fn2), \
        os.path.join("pelican", "content", row.id, row.filename)

class Filter:

    def __init__(self, filename = "tools/filter.json"):
        with open(filename) as f:
            filter = json.load(f)
        if not all(action in "-+" for action, pattern in filter):
            sys.exit("Bad action \"{}\" in filter".format(action))
        self.filter = tuple((action == "+", pattern) for action, pattern in filter)

    def __call__(self, name):
        for action, pattern in self.filter:
            if fnmatch.fnmatch(name, pattern):
                return action
        return True

class Row(sqlite3.Row):

    def __getattr__(self, name):
        return self[name]

    @property
    def isotime(self):
        return time.strftime("%Y-%m-%d %H:%M", time.gmtime(self.time))

def markdown_header(row, first_published):
    if row.name in first_published:
        modtime = "Modified: {}\n".format(row.isotime)
    else:
        modtime = ""
        first_published[row.name] = row.isotime
    return "Title: {}\nAuthor: {}\nDate: {}\n{}\n".format(row.name, row.author, first_published[row.name], modtime)

def main():
    ap = argparse.ArgumentParser()
    ap.add_argument("--source-url")
    args = ap.parse_args()

    for dn in ("wiki", "pelican"):
        if os.path.exists(dn):
            shutil.rmtree(dn)

    for dn in ("wiki", "pelican/content"):
        os.makedirs(dn)

    os.link("pelicanconf.py", "pelican/pelicanconf.py")

    wiki_to_markdown = trac2md.Trac2Markdown(args.source_url)

    keep = Filter()

    first_published = {}

    db = sqlite3.connect("trac.db")
    db.row_factory = Row

    for row in db.execute(wiki_query):
        if keep(row.name):
            with open("wiki/{}.trac".format(urllib.parse.quote(row.name, "")), "w") as f:
                f.write(row.text)
            md = markdown_header(row, first_published) + wiki_to_markdown(row.text, row.name)
            fn = "pelican/content/{}.md".format(row.name)
            dn = os.path.dirname(fn)
            if not os.path.exists(dn):
                os.makedirs(dn)
            with open(fn, "w") as f:
                f.write(md)

    for row in db.execute(attachment_query):
        src, dst = attachment_link(row)
        #print("{} => {}".format(dst, src))
        if not os.path.isdir(os.path.dirname(dst)):
            os.makedirs(os.path.dirname(dst))
        os.link(src, dst)

    db.close()

if __name__ == "__main__":
    main()