Migrate neuron zettelkastens to the new hash ID format

migrate.py

#!/usr/bin/env python3.8

import re
import sys
import os
import uuid
from pathlib import Path
import glob
import time
import datetime
import subprocess
from collections import namedtuple

SRC_ZK, DEST_ZK = map(Path, sys.argv[1:])

Zettel = namedtuple('Zettel', ['id', 'date', 'content'])

SHORT_LINK = re.compile(r"<([A-Za-z-_0-9]+)>")
MARKDOWN_LINK = re.compile(r"\[([A-Z-a-z-_0-9]+)\]\(((?:z(?:cf)?).*?)\)")

# date-id => hash id
remap = {}

def get_zettel_date(path):
    cmd = f"neuron -d {SRC_ZK} query --id {path.stem} | jq -r .result.day"
    return subprocess.run(cmd, shell=True, capture_output=True).stdout.decode("utf-8")

def generate_new_id():
    zid = '0'
    while zid.isdigit(): 
        zid = str(uuid.uuid4())[:8]
    return zid

def replace_links(md):
    repl_short_link = lambda match: f"<{remap[match.group(1)]}>"
    repl_markdown_link = lambda match: f"[{remap[match.group(1)]}]({match.group(2)})"
    step1 = re.sub(SHORT_LINK, repl_short_link, md)
    step2 = re.sub(MARKDOWN_LINK, repl_markdown_link, step1)
    return step2

def migrate_zettel(zettel):
    new_id = remap[zettel.id]
    with (DEST_ZK / f"{new_id}.md").open('w') as file:
        lines = replace_links(zettel.content).split('\n')
        file.writelines('\n'.join(lines[:2]))
        file.write(f"\ndate: {zettel.date}\n")
        file.writelines('\n'.join(lines[2:]))
    # Delete the old file (so effectively we are renaming it)
    # Recommended to use git before running this script.
    os.remove(DEST_ZK / f"{zettel.id}.md")

def make_zettel_from_path(path):
    with (SRC_ZK / path).open() as file:
        zid = path.stem
        content = file.read()
        date = get_zettel_date(path)
        return Zettel(zid, date, content)

def main():
    zettels = []
    # Migrate only date IDs.
    idPattern = f"[0-9]" * 7 + f"*.md"
    for zettel_path in map(Path, glob.glob(str(SRC_ZK / idPattern))):
        zettel = make_zettel_from_path(zettel_path)

        # Guessing whether it's a date or a custom ID
        if zettel.id.isdigit():
            remap[zettel.id] = generate_new_id() 
        else:
            # Keep non-date IDs since they can be meaningful
            remap[zettel.id] = zettel.id
            
        print(f"{zettel.id:<10} => {remap[zettel.id]}")
        zettels.append(zettel)

    for zettel in zettels:
        migrate_zettel(zettel)

if __name__ == '__main__':
    main()