#!/usr/bin/env bash

# This file is part of I38.

# I38 is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation,
# either version 3 of the License, or (at your option) any later version.

# I38 is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
# PURPOSE. See the GNU General Public License for more details.

# You should have received a copy of the GNU General Public License along with I38. If not, see <https://www.gnu.org/licenses/>.

screenlockPinHash=""
scriptPath="$(readlink -f "$0")"
scriptDir="${scriptPath%/*}"
i3Path="${scriptDir%/scripts}"
pinFile="${i3Path}/.screenpin"

if [[ -f "$pinFile" ]]; then
    read -r screenlockPinHash < "$pinFile"
fi

if [[ -z "$screenlockPinHash" ]]; then
    yad --title "I38" --text "Screen lock is not configured. Run i38.sh and set a 4-digit PIN to enable it." --button "Close:0"
    exit 1
fi

if ! command -v yad &> /dev/null; then
    exit 1
fi

if ! command -v jq &> /dev/null; then
    yad --title "I38" --text "Screen lock requires jq to determine the current workspace." --button "Close:0"
    exit 1
fi

if ! command -v sha512sum &> /dev/null; then
    yad --title "I38" --text "Screen lock requires sha512sum to validate the PIN." --button "Close:0"
    exit 1
fi

wmMsg="i3-msg"
if [[ -n "${SWAYSOCK:-}" ]] && command -v swaymsg &> /dev/null; then
    wmMsg="swaymsg"
elif [[ -n "${I3SOCK:-}" ]] && command -v i3-msg &> /dev/null; then
    wmMsg="i3-msg"
elif command -v swaymsg &> /dev/null; then
    wmMsg="swaymsg"
elif command -v i3-msg &> /dev/null; then
    wmMsg="i3-msg"
else
    yad --title "I38" --text "No i3 or sway command interface was found for screen lock." --button "Close:0"
    exit 1
fi

currentWorkspace="$($wmMsg -t get_workspaces | jq -r '.[] | select(.focused==true) | .name')"
lockWorkspace="i38-lock"
if $wmMsg -t get_workspaces | jq -e --arg name "$lockWorkspace" '.[] | select(.name==$name)' &> /dev/null; then
    lockWorkspace="i38-lock-$$"
fi

$wmMsg -t command "workspace --no-auto-back-and-forth \"$lockWorkspace\"" &> /dev/null
$wmMsg -t command "mode screenlock" &> /dev/null

attemptCount=0
while : ; do
    if [[ $attemptCount -eq 0 ]]; then
        promptText="Screen lock is enabled. Enter your 4-digit PIN to unlock."
    else
        promptText="Incorrect PIN. Enter your 4-digit PIN to unlock."
    fi

    pinInput="$(yad --entry --hide-text --title "I38" --text "$promptText" --entry-label "Screen lock PIN" --button "Unlock:0" --on-top --sticky --skip-taskbar --fixed --center --undecorated --fullscreen --no-escape)"
    yadResult=$?
    if [[ $yadResult -ne 0 ]]; then
        attemptCount=$((attemptCount + 1))
        continue
    fi

    if [[ ! "$pinInput" =~ ^[0-9]{4}$ ]]; then
        attemptCount=$((attemptCount + 1))
        continue
    fi

    pinHash="$(printf "%s" "$pinInput" | sha512sum | awk '{print $1}')"
    unset pinInput

    if [[ "$pinHash" == "$screenlockPinHash" ]]; then
        break
    fi

    attemptCount=$((attemptCount + 1))
done

$wmMsg -t command "mode default" &> /dev/null
if [[ -n "$currentWorkspace" ]]; then
    $wmMsg -t command "workspace \"$currentWorkspace\"" &> /dev/null
fi

exit 0