#!/usr/bin/env python

# convert the Glossatory archive from an ActivityPub collection to 
# gemini

import argparse
import datetime
import json
import re
from pathlib import Path
from shutil import copy
import sys

MNAMES = {
	"01": "January",
	"02": "February",
	"03": "March",
	"04": "April",
	"05": "May",
	"06": "June",
	"07": "July",
	"08": "August",
	"09": "September",
	"10": "October",
	"11": "November",
	"12": "December",
}



class MediaPost():
	def __init__(self, year, month, day, file, title, title_res=None):
		self.year = year
		self.month = month
		self.day = day
		self.file = file
		self.fname = Path(file).name
		self.title = title
		self.title_res = title_res
		self.defn = ""
		self.desc = ""
		if self.title_res:
			self.try_parse_title()

	def __str__(self):
		return f"{self.year}-{self.month}-{self.day}: {self.file}"

	def copy_image(self, root):
		d = Path(root) / self.year / self.month / self.day
		target = d / self.fname
		try:
			if not target.exists():
				copy(self.file, target)
		except FileNotFoundError as e:
			print(f"Image file missing: {self}", file=sys.stderr)

	def try_parse_title(self):
		for re in self.title_res:
			if m := re.match(self.title):
				self.title = ' '.join(m.groups())
				return
		print(f"{self.file} Couldn't match alt text {self.title}", file=sys.stderr)


def process_post(cf, archive, obj, debug=False):
	if debug:
		print(f"Processing {obj}", file=sys.stderr)
	date = datetime.datetime.strptime(obj["published"][:10], "%Y-%m-%d")
	year = f"{date.year}"
	month = f"{date.month:02}"
	day = f"{date.day:02}"
	if "attachment" not in obj or len(obj["attachment"]) < 1:
		raise ValueError('No attachments on this status')
	if len(obj["attachment"]) > 1:
		status_id = obj["id"]
		n = len(obj["attachment"])
		print(f"Warning: only one media item copied from post {status_id} which has {n}", file=sys.stderr)
	attachment = obj["attachment"][0]
	url = attachment["url"]
	if m:= cf["url_re"].match(url):
		file = Path(archive) / m.group(1)
	else:
		raise ValueError(f"Couldn't match url {url}")
	alt = attachment["name"]
	return MediaPost(year, month, day, file, alt, cf.get("title_res", None))


def ensure_dir(gmdir):
	if not gmdir.is_dir():
		gmdir.mkdir(parents=True)


def load_colophon(cfile):
	if cfile:
		with open(cfile, "r") as cfh:
			colophon = cfh.readlines()
			return "".join(colophon)
	return None


def load_config(config):
	with open(config, "r") as cfh:
		cf = json.load(cfh)
		cf["url_re"] = re.compile(cf["url_re"])
		if "title_res" in cf:
			cf["title_res"] = [ re.compile(r) for r in cf["title_res"] ]
	return cf


def write_gemfile(gmdir, colophon, title, items):
	ensure_dir(gmdir)
	gmi = gmdir / "index.gmi"
	with open(gmi, "w") as gfh:
		if colophon:
			gfh.write(colophon)
			gfh.write("\n\n")
		gfh.write(f"# {title}\n\n")
		for link, text in items:
			gfh.write(f"=> {link} {text}\n")


def apub2gmi(cf, archive, output, colophon, debug=False):
	with open(f"{archive}/outbox.json", "r") as fh:
		js = json.load(fh)
		posts = {}
		for item in js["orderedItems"]:
			if item["type"] == "Create":
				if debug:
					print(item)
				try:
					post = process_post(cf, archive, item["object"], debug)
					if not post.year in posts:
						posts[post.year] = {}
					if not post.month in posts[post.year]:
						posts[post.year][post.month] = {}
					m = posts[post.year][post.month]
					if not post.day in m:
						m[post.day] = [ post ]
					else:
						m[post.day].append(post)
				except Exception as e:
					i = item["id"]
					print(f"Processing failed: {i}: {e}")

		years = [ ( f"{year}/", year ) for year in posts ]
		write_gemfile(Path(output), colophon, "Glossatory", years)

		for year in posts:
			ydir = Path(output) / year
			months = [ ( f"{month}/", MNAMES[month] ) for month in posts[year] ]
			write_gemfile(ydir, colophon, year, months)
			for month in posts[year]:
				mname = MNAMES[month]
				mdir = ydir / month
				for day in posts[year][month]:
					ddir = mdir / day
					ddir.mkdir(parents=True, exist_ok=True)
					for post in posts[year][month][day]:
						post.copy_image(output)
				gmi = mdir / "index.gmi"
				links = [
					( f"/glossatory/{year}/", year),
				]
				for day in posts[year][month]:
					for post in posts[year][month][day]:
						links.append((f"{day}/{post.fname}", post.title))
				write_gemfile(mdir, colophon, f"{mname} {year}", links)


if __name__ == "__main__":
	ap = argparse.ArgumentParser()
	ap.add_argument(
		'-a', '--archive', required=True, type=str, help="ActivityPub archive"
		)
	ap.add_argument(
		'-o', '--output', required=True, type=str, help="Output directory"
		)
	ap.add_argument(
		'-c', '--config', required=True, type=str, help="Config file"
	)
	ap.add_argument(
		'-t', '--text', required=False, type=str,
		help="File with text to be included at the top of each index page"
		)
	ap.add_argument(
		'-d', '--debug', action="store_true", default=False,
		help="Print debug output"
		)
	args = ap.parse_args()
	cf = load_config(args.config)
	colophon = load_colophon(args.text)
	apub2gmi(cf, args.archive, args.output, colophon, args.debug)