#!/usr/bin/env bash

set -e

# Best-effort script to control volume of the focused application,
# falling back to the default sink.
#
# MODIFIED: Now checks for Spotify and uses 'playerctl' if found.
# MODIFIED: Pactl branch now matches on process binary name, not PID.

USAGE="Usage: $(basename "$0") WINDOW_ID [--up | --down | --set <0-100>]"
CHANGE_PCT="5" # Percent to change

# Get the focused window ID
FOCUSED_WIN_ID="$1"
shift;

ACTION=$1
ARGUMENT=$2

# --- Check if the window is Spotify ---
IS_SPOTIFY=0
if [ -n "$FOCUSED_WIN_ID" ] && [ "$FOCUSED_WIN_ID" != "0" ]; then
    # xprop output is: WM_CLASS(STRING) = "spotify", "Spotify"
    # We check for "spotify" case-insensitive
    if xprop -id "$FOCUSED_WIN_ID" WM_CLASS | grep -q -i "spotify"; then
        IS_SPOTIFY=1
    fi
fi


# --- BRANCH 1: SPOTIFY LOGIC (use playerctl) ---
if [ "$IS_SPOTIFY" -eq 1 ]; then
    echo "Spotify window detected. Using playerctl." >&2

    # playerctl volume is a float from 0.0 to 1.0
    # We use awk to convert our 5% to 0.05
    CHANGE_FLOAT=$(awk "BEGIN {print $CHANGE_PCT / 100}")

    case $ACTION in
        --up)
            playerctl --player=spotify volume "${CHANGE_FLOAT}+"
            ;;
        --down)
            playerctl --player=spotify volume "${CHANGE_FLOAT}-"
            ;;
        --set)
            # Convert 0-100 input to 0.0-1.0 float
            TARGET_VOL=$(awk "BEGIN {print $ARGUMENT / 100}")
            playerctl --player=spotify volume "$TARGET_VOL"
            ;;
        *)
            echo "$USAGE" >&2
            exit 1
            ;;
    esac

    # We are done. Exit successfully.
    exit 0
fi


# --- BRANCH 2: DEFAULT PACTL LOGIC (if not Spotify) ---
echo "Non-Spotify window. Using pactl." >&2

SINK_INPUT_INDEX=""
if [ -n "$FOCUSED_WIN_ID" ] && [ "$FOCUSED_WIN_ID" != "0" ]; then
    # Get the PID of the focused window
    PID=$(xprop -id "$FOCUSED_WIN_ID" _NET_WM_PID | awk '{print $NF}')

    if [ -n "$PID" ]; then
        # NEW: Get the binary name from the PID
        BINARY_NAME=$(ps -p "$PID" -o comm= | tr -d '[:space:]')
        echo "Looking for binary $BINARY_NAME"

        if [ -n "$BINARY_NAME" ]; then
            # Find PulseAudio sink input index for this BINARY_NAME
            # This is more robust than PID for apps like browsers
            SINK_INPUT_INDEX=$(pactl list sink-inputs | perl -ne '
      BEGIN {
        our $sink_id = -1;
        our $maybe_sink_id = -1;
      }
      if (/Sink Input #(\d+)/) {
        $maybe_sink_id = $1;
      }
      # Match the binary name, e.g., application.process.binary = "firefox"
      if (/application\.process\.binary = "'"$BINARY_NAME"'"/) {
        $sink_id = $maybe_sink_id;
      }
      END { print "$sink_id\n"; }
    ')
        fi
    fi
fi

CHANGE="${CHANGE_PCT}%"

set_volume() {
    local target=$1
    local diff=$2
    if [[ "$target" == *#* ]]; then
        echo "Setting volume for Sink Input $target ($diff)" >&2
        pactl set-sink-input-volume "${target#SINK INPUT #}" "$diff"
    else
        echo "Setting default sink volume ($diff)" >&2
        pactl set-sink-volume "$target" "$diff"
    fi
}

TARGET="@DEFAULT_SINK@"
if [ -n "$SINK_INPUT_INDEX" ] && [ "$SINK_INPUT_INDEX" -ne -1 ]; then
    TARGET="SINK INPUT #$SINK_INPUT_INDEX"
fi

case $ACTION in
    --up)
        set_volume "$TARGET" "+$CHANGE"
        ;;
    --down)
        set_volume "$TARGET" "-$CHANGE"
        ;;
    --set)
        # pactl can take a percentage directly
        set_volume "$TARGET" "${ARGUMENT}%"
        ;;
    *)
        echo "$USAGE" >&2
        exit 1
        ;;
esac