#!/usr/bin/env python3

from subprocess import check_call
import argparse
import json
import os
import sys


ADR_TEMPLATE_MD = """
---
{{- $num := index .Site.Data.adrs.current "number" -}}
{{- $title := index .Site.Data.adrs.index $num "name" -}}
title: "{{ $num }}. {{ $title }}"
date: {{ .Date }}
draft: true
topics:
- ADR
---
# {{ $num }}. {{ $title }}

Date: {{ dateFormat "2006-01-02" .Date }}

## Status

DRAFT

## Context

The issue motivating this decision, and any context that influences or
constrains the decision.

## Decision

The change that we're proposing or have agreed to implement.

## Consequences

What becomes easier or more difficult to do and any risks introduced by the
change that will need to be mitigated
""".strip()

ADR_DATA_DIR = os.path.join("data", "adrs")
ADR_CONTENT_DIR = os.path.join("content", "adrs")


def ensure_adr_archetype():
    adr_archetype = os.path.join("archetypes", "adrs.md")

    if not os.path.exists(adr_archetype):
        with open(adr_archetype, "w") as f:
            f.write(ADR_TEMPLATE_MD)


def write_adr_json(data: dict):
    with open(os.path.join(ADR_DATA_DIR, "index.json"), "w") as index:
        json.dump(data, index)


def load_adr_json() -> dict:
    with open(os.path.join(ADR_DATA_DIR, "index.json")) as index:
        return json.load(index)


def ensure_adr_data():
    if not os.path.exists(ADR_DATA_DIR):
        os.makedirs(ADR_DATA_DIR)

    if not os.path.exists(os.path.join(ADR_DATA_DIR, "index.json")):
        write_adr_json({})


def get_adr_number() -> int:
    adr_dir = os.path.join("content", "adrs")
    if not os.path.isdir(adr_dir):
        return 1

    num = 0

    items = [
        adr_file
        for adr_file in sorted(os.listdir(adr_dir))
        if os.path.isfile(os.path.join(adr_dir, adr_file))
    ]

    for i in items:
        num = max(num, int(i.split(".", 2)[0]))

    num += 1

    return num


def write_current_adr_number(num: int):
    data = {"number": f"{num:04}"}

    with open(os.path.join(ADR_DATA_DIR, "current.json"), "w") as current:
        json.dump(data, current)


def create_adr_file(num: int, name: str):
    adr_filename = f"{num:04}. {name}.md".lower().replace(" ", "-")

    write_current_adr_number(num)

    adr_data = load_adr_json()

    adr_data[f"{num:04}"] = {"name": name, "status": "DRAFT"}

    write_adr_json(adr_data)

    check_call(["hugo", "new", f"adrs/{adr_filename}"])


def main():
    argp = argparse.ArgumentParser()
    argp.add_argument("title", help="The title of your architectural decision record")

    args = argp.parse_args()

    ensure_adr_archetype()
    ensure_adr_data()

    adr_number = get_adr_number()

    create_adr_file(adr_number, args.title)


if __name__ == "__main__":
    if not os.path.isdir("archetypes"):
        print("You need to run this in a hugo project with an archetypes directory")
        sys.exit(1)

    main()