#!/usr/bin/env bash
set -euo pipefail

# Usage:
#   Waybar exec:        hyprscroll-overflow.sh
#   Waybar on-click:    hyprscroll-overflow.sh --pick
#
# Env:
#   COLUMN_WIDTH=0.5
#   ICON="󰓒"
#   DMENU_CMD="walker --dmenu"   (or: "wofi --dmenu", "rofi -dmenu", etc.)

COLUMN_WIDTH="${COLUMN_WIDTH:-0.5}"
ICON="${ICON:-󰓒}"
DMENU_CMD="${DMENU_CMD:-walker --dmenu}"

json_escape() {
  # minimal JSON string escape (quotes, backslashes, newlines, tabs, CR)
  local s="${1:-}"
  s="${s//\\/\\\\}"
  s="${s//\"/\\\"}"
  s="${s//$'\n'/\\n}"
  s="${s//$'\r'/\\r}"
  s="${s//$'\t'/\\t}"
  printf '%s' "$s"
}

fail_json() {
  # NOTE: errors SHOULD still show (so you notice), hence JSON output here.
  local msg="hyprscroll-overflow: ${1:-unknown error}"
  printf '{"text":"%s !","tooltip":"%s","class":"error"}\n' \
    "$(json_escape "$ICON")" "$(json_escape "$msg")"
  exit 0
}

need() { command -v "$1" >/dev/null 2>&1 || fail_json "$1 not in PATH"; }
need hyprctl
need jq
need awk

read -r focused_mon_id focused_ws_id < <(
  hyprctl -j monitors 2>/dev/null | jq -r '
    .[] | select(.focused==true) | "\(.id) \(.activeWorkspace.id)"
  '
) || fail_json "failed to read focused monitor/workspace"

[[ -n "${focused_mon_id:-}" && -n "${focused_ws_id:-}" ]] || fail_json "no focused monitor/workspace"

# Current layout (needed for both normal + --pick paths)
layout="$(hyprctl getoption general:layout 2>/dev/null | awk '/str:/ {print $2; exit}' || true)"
layout="${layout:-}"

# Collect windows (current ws + current monitor, mapped only)
clients_json="$(hyprctl -j clients 2>/dev/null)" || fail_json "failed to read clients"

# Click action: pick a window and focus it
if [[ "${1:-}" == "--pick" ]]; then
  # Build menu lines: address at end so we can parse it back reliably.
  menu="$(
    jq -r --argjson ws "$focused_ws_id" --argjson mid "$focused_mon_id" '
      [ .[]
        | select(.mapped == true)
        | select(.workspace.id == $ws)
        | select(.monitor == $mid)
        | {address, class, title}
      ]
      | map("[\(.class)] \(.title)    \(.address)")
      | .[]
    ' <<<"$clients_json"
  )" || exit 0

  [[ -n "${menu:-}" ]] || exit 0

  # shellcheck disable=SC2086
  choice="$(printf '%s\n' "$menu" | eval "$DMENU_CMD" || true)"
  [[ -n "${choice:-}" ]] || exit 0

  addr="$(awk '{print $NF}' <<<"$choice")"
  [[ "$addr" =~ ^0x[0-9a-fA-F]+$ ]] || exit 0

  hyprctl dispatch focuswindow "address:${addr}" >/dev/null 2>&1 || exit 0
  exit 0
fi

# Tooltip list (multiline)
# Include a stable selector: address (hex), plus class + title for humans.
tooltip_list="$(
  jq -r --argjson ws "$focused_ws_id" --argjson mid "$focused_mon_id" '
    [ .[]
      | select(.mapped == true)
      | select(.workspace.id == $ws)
      | select(.monitor == $mid)
      | {address, class, title}
    ]
    | to_entries
    | map("\(.key+1). [\(.value.class)] \(.value.title)  (\(.value.address))")
    | .[]
  ' <<<"$clients_json"
)" || fail_json "failed to build tooltip list"

win_count="$(
  jq -r --argjson ws "$focused_ws_id" --argjson mid "$focused_mon_id" '
    [ .[]
      | select(.mapped == true)
      | select(.workspace.id == $ws)
      | select(.monitor == $mid)
    ] | length
  ' <<<"$clients_json"
)" || fail_json "failed to count clients"

max_visible="$(awk -v w="$COLUMN_WIDTH" 'BEGIN{ if (w<=0) {print 1} else {print int(1.0/w)} }')" \
  || fail_json "awk failed"
(( max_visible < 1 )) && max_visible=1

overflow=$(( win_count - max_visible ))

# IMPORTANT: hide module by outputting NOTHING (no JSON) when not relevant
if (( overflow <= 0 )) || [[ "$layout" != "scrolling" ]]; then
  exit 0
fi

text="$ICON +$overflow"
cls="overflow"

tooltip="WS ${focused_ws_id} • ${win_count} window(s)\n"
tooltip+="Approx ${max_visible} fit (column_width=${COLUMN_WIDTH})\n"
tooltip+="------------------------------\n"
tooltip+="${tooltip_list:-"(no windows)"}"

printf '{"text":"%s","tooltip":"%s","class":"%s"}\n' \
  "$(json_escape "$text")" \
  "$(json_escape "$tooltip")" \
  "$(json_escape "$cls")"