#!/usr/bin/env python3

import concurrent.futures
import dataclasses
import json
import os
import re
import subprocess
import sys
import urllib.request
from dataclasses import dataclass
from typing import Any, TextIO


FILENAME = "locales.gen.go"

class Rune(int):
	pass


@dataclass
class Locale:
	bcp: str
	eurozonep: bool
	enabledp: bool
	territory: str | None             = dataclasses.field(default=None)
	name: str                         = dataclasses.field(init=False)
	date_format: str                  = dataclasses.field(init=False)
	group_separator: Rune             = dataclasses.field(init=False)
	decimal_separator: Rune           = dataclasses.field(init=False)
	monetary_formats: tuple[str, str] = dataclasses.field(init=False)
	percent_format: str               = dataclasses.field(init=False)


LOCALES = (
	Locale(bcp="ca", eurozonep=True,  enabledp=False),
	Locale(bcp="de", eurozonep=True,  enabledp=False),
	Locale(bcp="el", eurozonep=True,  enabledp=False),
	Locale(bcp="en", eurozonep=True,  enabledp=True,  territory="GB"),
	Locale(bcp="es", eurozonep=True,  enabledp=False),
	Locale(bcp="et", eurozonep=True,  enabledp=False),
	Locale(bcp="fi", eurozonep=True,  enabledp=False),
	Locale(bcp="fr", eurozonep=True,  enabledp=False),
	Locale(bcp="ga", eurozonep=True,  enabledp=False),
	Locale(bcp="hr", eurozonep=True,  enabledp=False),
	Locale(bcp="it", eurozonep=True,  enabledp=False),
	Locale(bcp="lb", eurozonep=True,  enabledp=False),
	Locale(bcp="lt", eurozonep=True,  enabledp=False),
	Locale(bcp="lv", eurozonep=True,  enabledp=False),
	Locale(bcp="mt", eurozonep=True,  enabledp=False),
	Locale(bcp="nl", eurozonep=True,  enabledp=True),
	Locale(bcp="pt", eurozonep=True,  enabledp=False, territory="PT"),
	Locale(bcp="sk", eurozonep=True,  enabledp=False),
	Locale(bcp="sl", eurozonep=True,  enabledp=False),
	Locale(bcp="sv", eurozonep=True,  enabledp=True),
	Locale(bcp="tr", eurozonep=True,  enabledp=False),
	Locale(bcp="bg", eurozonep=False, enabledp=False),
	Locale(bcp="ro", eurozonep=False, enabledp=False),
	Locale(bcp="uk", eurozonep=False, enabledp=False),
)

BASELINK = "https://raw.githubusercontent.com/unicode-org/cldr-json/refs/heads/main/cldr-json/%s/main/%%s/%s"
NUMBERS_LINK, DATES_LINK, LANGUAGES_LINK = (
	BASELINK % ("cldr-numbers-full", "numbers.json"),
	BASELINK % ("cldr-dates-full", "ca-gregorian.json"),
	BASELINK % ("cldr-localenames-full", "languages.json"),
)


def main() -> int:
	rv = 0
	nprocs = os.cpu_count()
	with concurrent.futures.ThreadPoolExecutor(max_workers=nprocs) as executor:
		for x in [executor.submit(write_locale, l) for l in LOCALES]:
			try:
				x.result()
			except Exception as e:
				print(f"gen.py: {e}", file=sys.stderr)
				rv = 1

	with open(FILENAME, "w") as f:
		f.write("""// Code generated by gen.py.  DO NOT EDIT.

package i18n

import "github.com/leonelquinteros/gotext"

type LocaleInfo struct {
	Bcp, Name                        string
	Eurozonep, Enabledp              bool
	DateFormat                       string
	GroupSeparator, DecimalSeparator rune
	MonetaryFormats                  [2]string
	PercentFormat                    string
}

var locales = [...]LocaleInfo{
""")
		for x in LOCALES:
			f.write("{\n")
			for k, v in x.__dict__.items():
				if not v or k == "territory":
					continue
				if k == "name":
					f.write('Name: gotext.GetC(%s, "Language Name"),\n' % val_to_go(v))
				else:
					f.write("%s: %s,\n" % (pascal(k), val_to_go(v)))
			f.write("},\n")
		f.write("}")

	subprocess.run(["gofmt", "-w", FILENAME])
	return rv


def write_locale(l: Locale) -> None:
	bcp = '%s-%s' % (l.bcp, l.territory) if l.territory else l.bcp
	jn, jd, jl = map(json.load, (
		urllib.request.urlopen(NUMBERS_LINK % bcp),
		urllib.request.urlopen(DATES_LINK % bcp),
		urllib.request.urlopen(LANGUAGES_LINK % bcp),
	))
	name = jl["main"][bcp]["localeDisplayNames"]["languages"][l.bcp]
	l.name = name.capitalize()
	syms = jn["main"][bcp]["numbers"]["symbols-numberSystem-latn"]
	l.group_separator   = Rune(ord(syms["group"]))
	l.decimal_separator = Rune(ord(syms["decimal"]))

	fmt = jn["main"][bcp]["numbers"]["percentFormats-numberSystem-latn"]["standard"]
	l.percent_format = numfmt_subst(fmt)

	fmt = jd["main"][bcp]["dates"]["calendars"]["gregorian"]["dateFormats"]["short"]
	l.date_format = (
		fmt
			.replace("yy", "06")
			.replace("MM", "01")
			.replace("dd", "02")
			.replace("y", "2006")
			.replace("M", "1")
			.replace("d", "2")
			.replace("'", "")
	)

	fmt = jn["main"][bcp]["numbers"]["currencyFormats-numberSystem-latn"]["standard"]
	parts = list(map(numfmt_subst, fmt.replace("¤", "€").split(";")))
	if len(parts) == 1:
		parts.append('-' + parts[0])
	l.monetary_formats = tuple(parts)


def numfmt_subst(s: str) -> str:
	return re.sub(r"[0#,.]+", "123", s)


def pascal(s: str) -> str:
	return ''.join(map(str.capitalize, s.split('_')))


def val_to_go(x: Any) -> str:
	match x:
		case bool():
			return "true" if x else "false"
		case Rune():
			return "'%s'" % chr(x)
		case str():
			return '"%s"' % x
		case (str(), str()):
			return "[2]string{%s, %s}" % (val_to_go(x[0]), val_to_go(x[1]))


if __name__ == "__main__":
	os.chdir(os.path.dirname(sys.argv[0]))
	sys.exit(main())