#!/usr/bin/env bash
# scripts/gen-keybinds.sh — generate the niri keybinding cheat sheet (markdown)
# from a keybinds.kdl file.
#
# Usage:
#   gen-keybinds.sh [keybinds.kdl]              # markdown to stdout
#   gen-keybinds.sh [keybinds.kdl] --write OUT  # markdown to OUT
#
# Default input: ~/.config/niri/cfg/keybinds.kdl
# Recognized: section comments `// ─── Name ───`, bind lines with optional
# hotkey-overlay-title="..."; the action inside { } is used when there is no title.

set -euo pipefail

usage() { sed -n '2,11p' "$0" | sed 's/^# \{0,1\}//'; }

KBD=""
OUT=""
while [ $# -gt 0 ]; do
  case "$1" in
    -h|--help) usage; exit 0 ;;
    --write)   OUT="${2:?--write needs an output path}"; shift 2 ;;
    *)         KBD="$1"; shift ;;
  esac
done
KBD="${KBD:-$HOME/.config/niri/cfg/keybinds.kdl}"
[ -f "$KBD" ] || { echo "error: no such file: $KBD" >&2; exit 1; }

gen() {
  echo "---"
  echo "type: reference"
  echo "title: Niri Keybindings"
  echo "description: Live keybinding cheat sheet generated from $(basename "$KBD") — do not edit by hand."
  echo "tags:"
  echo "  - niri"
  echo "  - keybindings"
  echo "generated: { by: scripts/gen-keybinds.sh }"
  echo "---"
  echo
  echo "# Niri Keybindings"
  echo
  echo "> GENERATED by \`scripts/gen-keybinds.sh\` from \`$(basename "$KBD")\` — do not edit by hand."
  echo
  awk '
    # Section marker: a comment decorated with box-drawing dashes on both sides,
    # `// ─── Name ───`. The dash is matched as a LITERAL and removed with gsub — never
    # with a quantifier on the multibyte character. Under LC_ALL=C (cron, systemd units,
    # agent shells) gawk works byte-wise, `─+` then means "the last byte of ─, repeated",
    # and every header vanishes while the script still exits 0. Plain comments stay
    # comments: only a dash-decorated one opens a section.
    /^[[:space:]]*\/\/[[:space:]]*─/ {
      s = $0
      sub(/^[[:space:]]*\/\/[[:space:]]*/, "", s)
      sub(/[[:space:]]+$/, "", s)
      if (s ~ /─ .*─/) {
        gsub(/─/, "", s)
        gsub(/[[:space:]]+/, " ", s)
        sub(/^ /, "", s); sub(/ $/, "", s)
        if (in_table) print ""
        print "## " s
        print ""
        print "| Key | Action |"
        print "|-----|--------|"
        in_table = 1
      }
      next
    }
    # bind line: KEY [flags] [hotkey-overlay-title="..."] { action; }
    /^[[:space:]]*[A-Z][A-Za-z0-9+]*( |$)/ && /\{/ {
      key = $1
      title = ""
      if (match($0, /hotkey-overlay-title="[^"]*"/)) {
        title = substr($0, RSTART + 22, RLENGTH - 23)
      }
      act = ""
      if (match($0, /\{[^}]*\}/)) {
        act = substr($0, RSTART + 1, RLENGTH - 2)
        sub(/;[[:space:]]*$/, "", act)
        gsub(/[[:space:]]+/, " ", act)
        sub(/^ /, "", act); sub(/ $/, "", act)
      }
      out = (title != "") ? title : act
      gsub(/\|/, "\\|", out)
      print "| `" key "` | " out " |"
      n++
      next
    }
    END {
      if (in_table) print ""
      printf("<!-- %d bindings -->\n", n) > "/dev/stderr"
    }
  ' "$KBD"
}

if [ -n "$OUT" ]; then
  mkdir -p "$(dirname "$OUT")"
  gen > "$OUT"
  echo "wrote $OUT" >&2
else
  gen
fi