#!/usr/bin/env bash
# Invoked by Sunshine as a stream-start hook (global_prep_cmd `do`).
# Creates/resizes a Hyprland headless output to match the connecting
# Moonlight client's resolution, and moves the active workspace onto it
# so the user's existing windows are visible on the stream.
#
# Sunshine env vars set on connect:
#   SUNSHINE_CLIENT_WIDTH, SUNSHINE_CLIENT_HEIGHT, SUNSHINE_CLIENT_FPS

set -euo pipefail

log() { printf '[sunshine-do] %s\n' "$*" >&2; }

WIDTH="${SUNSHINE_CLIENT_WIDTH:-1920}"
HEIGHT="${SUNSHINE_CLIENT_HEIGHT:-1080}"
FPS="${SUNSHINE_CLIENT_FPS:-60}"
STATE_DIR="${XDG_RUNTIME_DIR:-/tmp}/sunshine-headless"
mkdir -p "$STATE_DIR"

if ! command -v hyprctl >/dev/null 2>&1; then
  log "hyprctl not found; cannot configure headless. Stream will use whatever output Sunshine selects."
  exit 0
fi

# Recover Hyprland signature if it wasn't inherited (defensive — UWSM exports it,
# but a stray service environment could miss it).
if [[ -z "${HYPRLAND_INSTANCE_SIGNATURE:-}" ]]; then
  for sig_dir in "${XDG_RUNTIME_DIR:-/tmp}"/hypr/*/; do
    [[ -d "$sig_dir" ]] || continue
    export HYPRLAND_INSTANCE_SIGNATURE="$(basename "$sig_dir")"
    log "Discovered HYPRLAND_INSTANCE_SIGNATURE=$HYPRLAND_INSTANCE_SIGNATURE"
    break
  done
  if [[ -z "${HYPRLAND_INSTANCE_SIGNATURE:-}" ]]; then
    log "Hyprland not running; nothing to configure."
    exit 0
  fi
fi

# Snapshot prior state so undo can restore.
hyprctl monitors -j > "$STATE_DIR/prev-monitors.json" 2>/dev/null || true
PREV_WS="$(hyprctl activeworkspace -j 2>/dev/null | jq -r '.id // 1' || echo 1)"
echo "$PREV_WS" > "$STATE_DIR/prev-workspace-id"

# Discover whatever headless output already exists. sunshine-prestart.sh is
# responsible for ensuring one exists and aligning sunshine.conf's output_name
# to its actual name (Hyprland's HEADLESS-N counter drifts across restarts).
MON="$(hyprctl monitors -j 2>/dev/null \
  | jq -r '.[] | select(.name | startswith("HEADLESS")) | .name' | head -1)"
if [[ -z "$MON" ]]; then
  log "No headless output found; creating one"
  hyprctl output create headless >/dev/null
  for _ in 1 2 3 4 5; do
    MON="$(hyprctl monitors -j 2>/dev/null \
      | jq -r '.[] | select(.name | startswith("HEADLESS")) | .name' | head -1)"
    [[ -n "$MON" ]] && break
    sleep 0.1
  done
fi
if [[ -z "$MON" ]]; then
  log "Failed to obtain a headless output; bailing."
  exit 0
fi
echo "$MON" > "$STATE_DIR/headless-name"

# Resize headless to the client's resolution / framerate.
log "Sizing $MON → ${WIDTH}x${HEIGHT}@${FPS}"
hyprctl keyword monitor "$MON,${WIDTH}x${HEIGHT}@${FPS},auto,1" >/dev/null

# Move the active workspace onto the headless so existing windows appear in the stream.
log "Moving workspace $PREV_WS → $MON, focusing it"
hyprctl dispatch moveworkspacetomonitor "$PREV_WS $MON" >/dev/null || true
hyprctl dispatch focusmonitor "$MON" >/dev/null || true

log "Stream ready: ${WIDTH}x${HEIGHT}@${FPS} on $MON"