#!/bin/bash
# SPDX-License-Identifier: MIT
# SPDX-FileCopyrightText: Copyright 2023 SUSE LLC
set -e

# config options
PR_SRC_USER=
PR_PROJECT=
PR_REPO=
TOKEN=

# command line only
verbose=0
cfg_file=

###################

requestfile=$(mktemp gitea-pulls.XXXXXX)
tmpfile=$(mktemp gitea-pulls.XXXXXX)
cleanup()
{
	rm -f "$requestfile" "$tmpfile"
}
trap cleanup EXIT

helpandquit()
{
	cat <<-EOF
		Usage: $0 [OPTIONS]
		OPTIONS:
		  --verbsoe  verbose
		  -h         help screen
	EOF
	exit 0
}

log_info()
{
	[ "$verbose" -gt 0 ] || return 0
	echo "$@"
}

d(){
	local retval=0
	# Bash makes it a bit annoying to read the output of a different FD into a variable, it
	# only supports reading stdout by itself. So redirect 3 to stdout and 1 to the real stdout.
	exec {stdoutfd}>&1
	result="$(dialog --backtitle "Gita Pull requests" --output-fd 3 "$@" 3>&1 1>&${stdoutfd})" || retval=$?
	# Word splitting makes it necessary to use eval here.
	eval "exec ${stdoutfd}>&-"
	return "$retval"
}

# Given the number of total item pairs, outputs the number of items to display at once
menuheight() {
	local height=$(($1 / 2))
	[ "$height" -le "$dh_menu" ] || height="$dh_menu"
	echo "$height"
}

stty_size() {
	set -- $(stty size)
	LINES="$1"
	COLUMNS="$2"
	# stty size can return zero when not ready or
	# its a serial console
	if [ "$COLUMNS" = "0" ] || [ "$LINES" = "0" ]; then
		LINES=24
		COLUMNS=80
	fi

	dh_menu=$((LINES-15))
	dh_text=$((LINES-5))
}
stty_size

getopttmp=$(getopt -o hc:v --long help,config:,verbose -n "${0##*/}" -- "$@")
eval set -- "$getopttmp"

while true ; do
        case "$1" in
                -h|--help) helpandquit; shift ;;
		-v|--verbose) verbose=$((++verbose)); shift ;;
                -c|--config) cfg_file="$2"; shift 2 ;;
                --) shift ; break ;;
                *) echo "Internal error!" ; exit 1 ;;
        esac
done

# shellcheck disable=SC1090
. "${cfg_file:-.settings}"

needed=(PR_SRC_USER PR_PROJECT PR_REPO TOKEN)
for i in "${needed[@]}"; do
	eval test -n "\"\$$i\"" || { echo "The following settings are mandatory: ${needed[*]}"; exit 1; }
done

request()
{
	local urlpart="$1"
	shift
	curl -s -f "https://gitea.opensuse.org/api/v1/repos/$PR_PROJECT/$PR_REPO$urlpart" \
		-H "accept: application/json" \
		-H "Authorization: token $TOKEN" \
		-H "Content-Type: application/json" "$@"
}

fetch_requests()
{
	request "/pulls?state=open" > "$requestfile"
}

fetch_requests

while true; do
	list=()
	while read -r number _branch _cid owner title; do
		list+=("$number" "$owner: $title")
	done < <(jq '.[]|[((.number|tostring)), .head.ref, .head.sha, .head.repo.owner.login, .title]|join(" ")' -r < "$requestfile")
	if [ "${#list}" = 0 ]; then
		d --msgbox "No pull requests in $PR_PROJECT/$PR_REPO" 0 0
		exit 0
	fi
	d --no-hot-list --menu "$PR_PROJECT/$PR_REPO pull requests" 0 0 "$(menuheight ${#list[@]})" "${list[@]}" || exit 1
	prno="$result"

	while true; do
		list=(raw raw diff diff merge merge close close)
		d --no-tags --menu "$PR_PROJECT/$PR_REPO #$prno" 0 0 "$(menuheight ${#list[@]})" "${list[@]}" || break
		action="$result"

		case "$action" in
			raw)
				jq ".[]|select(.number==$prno)" < "$requestfile" > "$tmpfile"
				d --textbox "$tmpfile" 0 0
				;;
			diff)
				request "/pulls/$prno.diff" > "$tmpfile"
				d --textbox "$tmpfile" 0 0
				;;
			merge)
				request "/pulls/$prno/merge" -d '{ "do": "merge", "delete_branch_after_merge": true}' | jq > "$tmpfile"
				d --textbox "$tmpfile" 0 0
				fetch_requests
				break
				;;
			close)
				request "/pulls/$prno" -d '{ "state": "closed"}' -X PATCH | jq > "$tmpfile"
				d --textbox "$tmpfile" 0 0
				fetch_requests
				break
				;;
		esac
	done
done