git-gh-pr

#!/usr/bin/env bash

set -eu
set -o pipefail
shopt -s lastpipe

function o
{
	printf -->&2 "%s:%s\n" "${0##*/}" "$(printf " %q" "$@")"
	"$@"
}

function croak {
	local ex=$1; shift
	printf -->&2 "xxx> %s: %s\n" "${0##*/}" "$*"
	exit $ex
}

function do-curl
{
	if [[ -z ${github_token-} ]]; then
		github_token=$(yq -r '."github.com"[0].oauth_token' ~/.config/hub)
	fi

	curl --silent --show-error --fail --location -H "Authorization: token ${github_token}" "$@"
}

function get-pr
{
	o do-curl "https://api.github.com/repos/${gh_owner}/${gh_repo}/pulls/${1}"
}

function read-pr-info
{
	get-pr "$1" \
	| jq -r '.head.ref, .head.user.login, if .head.repo.private then .head.repo.ssh_url else .head.repo.clone_url end' \
	| {
		IFS= read -r pr_branch
		IFS= read -r pr_owner
		IFS= read -r pr_repo_url
	}
}

function read-owner-repo
{
	local origin_url
	o git remote get-url origin | IFS= read -r origin_url
	if [[ "$origin_url" =~ ^(git@)?github\.com:(.*)/(.*)\.git$ ]]; then
		gh_owner="${BASH_REMATCH[2]}"
		gh_repo="${BASH_REMATCH[3]}"
		:
	elif [[ "$origin_url" =~ ^(https?|git)://github\.com/(.*)/(.*)$ ]]; then
		gh_owner="${BASH_REMATCH[2]}"
		gh_repo="${BASH_REMATCH[3]}"
		gh_repo="${gh_repo%/}"
		gh_repo="${gh_repo%.git}"
		gh_repo="${gh_repo%/}"
		:
	else
		croak 1 Cannot parse: "$origin_url"
	fi
}

function add-remote
{
	if ! o git remote get-url "$1" >&/dev/null; then
		o git remote add "$1" "$2"
		o git config remote."$1".skipDefaultUpdate true
	fi
}

function check-git-repo
{
	o git rev-parse --git-dir >/dev/null
}

function prepare
{
	check-git-repo
	read-owner-repo
	read-pr-info "$pr_number"
	add-remote "$pr_owner" "$pr_repo_url"
	o git fetch "$pr_owner" "$pr_branch"

	local_branch="${pr_owner}-${pr_branch}"
	o git branch --track "$local_branch" "${pr_owner}/${pr_branch}"
}

function fetch
{
	pr_number="$1"
	prepare
}

function checkout
{
	pr_number="$1"
	prepare
	o git checkout "$local_branch"
}

function worktree
{
	pr_number="$1"
	prepare
	o git worktree add "../${gh_repo}-${local_branch}" "$local_branch"
}

"$@"