Script to simplify display switching in KDE with Sunshine remote

sunshine_screen.bash

#!/usr/bin/env bash

LOG_FILE="$HOME/.cache/sunshine_screen.log"
STATE_FILE="$HOME/.cache/sunshine_state"
mkdir -p "$(dirname "$STATE_FILE")"

log() { echo "$(date '+%Y-%m-%d %H:%M:%S') - $*" >> "$LOG_FILE"; }

# Dependency check
if ! command -v kscreen-doctor &>/dev/null || ! command -v jq &>/dev/null; then
  log "Error: kscreen-doctor or jq missing"
  exit 1
fi

# Check for reset flag
reset_display=0
for arg in "$@"; do
  [[ "$arg" == "--reset-display" ]] && reset_display=1
done

if [[ $reset_display -eq 1 ]]; then
  log "Action: RESET"
  if [[ -f "$STATE_FILE" ]]; then
    # Read saved state: ID WIDTH HEIGHT REFRESH
    read -r saved_id width height refresh < "$STATE_FILE"
    log "Restoring saved state: ${width}x${height}@${refresh} on output ${saved_id}"
    rm "$STATE_FILE"
    id="$saved_id"
  else
    log "No state file found, falling back to max native resolution"
    # Fallback: Restore to the highest resolution supported by the monitor
    read -r id width height refresh < <(
      kscreen-doctor -j | jq -r '.outputs | min_by(.priority) | . as $out | .modes | max_by(.size.width * .size.height) as $m | "\($out.id) \($m.size.width) \($m.size.height) \($m.refreshRate | floor)"'
    )
  fi
else
  log "Action: CONNECT"
  # Capture ORIGINAL state only if not already saved
  if [[ ! -f "$STATE_FILE" ]]; then
    # Exact filter verified against user JSON: matches currentModeId
    kscreen-doctor -j | jq -r '
      .outputs | min_by(.priority) | . as $out | 
      .modes[] | select(.id == $out.currentModeId) | 
      "\($out.id) \(.size.width) \(.size.height) \(.refreshRate | floor)"
    ' > "$STATE_FILE"
    
    saved_state=$(cat "$STATE_FILE")
    if [[ -z "$saved_state" ]]; then
      log "CRITICAL: Failed to capture original state using currentModeId!"
      # Last resort fallback to max mode
      kscreen-doctor -j | jq -r '.outputs | min_by(.priority) | . as $out | .modes | max_by(.size.width * .size.height) as $m | "\($out.id) \($m.size.width) \($m.size.height) \($m.refreshRate | floor)"' > "$STATE_FILE"
      saved_state=$(cat "$STATE_FILE")
    fi
    log "Saved original state: $saved_state"
  fi

  # Resolve target values from environment variables
  width="${APOLLO_CLIENT_WIDTH:-$SUNSHINE_CLIENT_WIDTH}"
  height="${APOLLO_CLIENT_HEIGHT:-$SUNSHINE_CLIENT_HEIGHT}"
  refresh="${APOLLO_CLIENT_FPS:-$SUNSHINE_CLIENT_FPS}"

  # Fallback to the saved native resolution if env vars are missing
  if [[ -z "$width" ]]; then
     # shellcheck disable=SC2034
     read -r _ width height refresh < "$STATE_FILE"
  fi
  
  # Ensure we have a valid ID
  id=$(awk '{print $1}' "$STATE_FILE")
  log "Targeting client mode: ${width}x${height}@${refresh} on output ${id}"
fi

# Final formatting: ensure refresh is an integer
refresh=$(LC_NUMERIC=C printf '%.0f' "$refresh" 2>/dev/null || echo "$refresh")

# Execute with a retry to handle KWin busy states
if ! kscreen-doctor "output.${id}.mode.${width}x${height}@${refresh}" &>> "$LOG_FILE"; then
  log "Command failed, retrying in 0.5s..."
  sleep 0.5
  kscreen-doctor "output.${id}.mode.${width}x${height}@${refresh}" &>> "$LOG_FILE"
fi