#!/usr/bin/env python3

# src:
# https://git.sr.ht/~sircmpwn/dotfiles/blob/f9e7e88a72c2b87e5ab823205cb3a3aa8f3babd0/bin/semver
# usage: semver [patch|minor|major|<new_version>]
# desc: will tag a new version either based on last tag or <new_version>
#
# patch(robertgzr)
# allow tagging a new non-annotated release

import getopt
import io
import os
import subprocess
import sys
import tempfile
import time

dry_run = False
simple_tag = True
force = False
changelog = False
push = False


def exec(args, dry_run=False, strict=True):
    print(f"+ {args}")
    if not dry_run:
        p = subprocess.run(args, stdout=subprocess.PIPE)
        if strict and p.returncode != 0:
            print(f"ERROR: {' '.join(args)} returned nonzero exit code")
            sys.exit(1)
        return p.stdout.decode().strip()


def usage():
    print(f"usage: {os.path.basename(sys.argv[0])} OPTIONS COMMANDS")
    print("""
bump the previous tag and create a new one

OPTIONS:
\t-h\tshow this help
\t-a\tannotate tag
\t-f\toverwrite existing tag
\t-c\twrite CHANGELOG
\t-p\tpush changes
\t-n\tdry run

COMMANDS:
\tpatch
\tminor
\tmajor
          """)
    sys.exit(2)


try:
    opts, argv = getopt.getopt(sys.argv[1:], 'afcpnh')
except getopt.GetoptError as err:
    print(err)
    usage()

for o, val in opts:
    if o == "-a":
        simple_tag = not simple_tag
    elif o == "-f":
        force = not force
    elif o == "-c":
        changelog = not changelog
    elif o == "-p":
        push = not push
    elif o == "-n":
        dry_run = not dry_run
    elif o == "-h":
        usage()
    else:
        assert False, "unhandled option"

if any(item in ["-h", "--help", "help"] for item in argv):
    usage()

if len(argv) < 1 or len(argv) > 1:
    usage()

if exec(["git", "branch", "--show-current"]) != "master":
    print("WARNING: not on master branch.")

exec(["git", "pull", "--dry-run", "--rebase"])

describe = exec(["git", "describe", "--abbrev=0", "--tags"], strict=False)
# TODO also ask to re-append the trailing portion.... e.g. -rev1

prepend = None

if describe:
    if describe[0] == 'v':
        describe = describe[1:]
        prepend = 'v'

    old_version = describe.split("-")[0].split(".")
    if len(old_version) == 2:
        [major, minor] = old_version
        [major, minor] = map(int, [major, minor])
        patch = 0
    elif len(old_version) == 3:
        [major, minor, patch] = old_version
        [major, minor, patch] = map(int, [major, minor, patch])

    else:
        print(
            f"WARNING: git describe returned invalid semver version: \"{describe}\""
        )
        sys.exit(1)

    old_version_revision = exec(["git", "log", "--pretty=%H", "-1", describe])
    head_revision = exec(["git", "log", "--pretty=%H", "-1", "HEAD"])
    if old_version_revision == head_revision:
        print(f"WARNING: HEAD already tagged as {describe}")
        if not force:
            sys.exit(0)

if (not simple_tag) or changelog:
    previous = describe and describe + ".."
    if prepend:
        previous = prepend + previous
    shortlog = exec(["git", "shortlog", "--no-merges", f"{previous}HEAD"])
    if not shortlog:
        print(f"WARNING: no shortlog")
        sys.exit(1)
    else:
        print(f"{shortlog}")

new_version = None

if argv[0] == "patch":
    patch += 1
elif argv[0] == "minor":
    minor += 1
    patch = 0
elif argv[0] == "major":
    major += 1
    minor = patch = 0
else:
    new_version = argv[0]

if not new_version:
    if len(old_version) == 2 and patch == 0:
        new_version = f"{major}.{minor}"
    else:
        new_version = f"{major}.{minor}.{patch}"

if prepend and (new_version[0] != 'v'):
    new_version = prepend + new_version

if os.path.exists("contrib/_incr_version"):
    exec(["contrib/_incr_version", describe, new_version])

args = ["git", "tag"]
if force:
    args.extend(["-f"])

if simple_tag:
    args.extend(["-m", new_version, new_version])
    exec(args, dry_run)
else:
    with tempfile.NamedTemporaryFile() as f:
        f.write(new_version.encode())
        f.write(f"\n\n".encode())
        f.write(shortlog.encode())
        f.flush()
        args.extend(["-F", f.name, "-a", new_version])
        exec(args, dry_run)

if changelog:
    changelog = io.StringIO()
    changelog.write(
        f"\n{new_version} ({time.strftime('%Y-%m-%d', time.localtime())})\n\n")
    changelog.write(shortlog)
    if dry_run:
        print("+ [writing changelog]")
        print(changelog.getvalue())
    else:
        with open("CHANGELOG", "w+") as f:
            changelog.write(f.read())
            f.seek(0)
            f.write(changelog)
            f.flush()

if push:
    exec(["git", "push", "origin", "HEAD", new_version], dry_run)