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

layouts=${1:-}
variants=${2:-}
active_index=${3:-0}
keyboard=${4:-}
remap_b64=${5:-}
config="${HOME}/.config/hypr/input.lua"
symbols_dir="${HOME}/.config/xkb/symbols"
symbols_file="${symbols_dir}/omarchy-keymaps"

if [[ ! "$layouts" =~ ^[[:alnum:]_,-]+$ ]] || [[ -z "$layouts" ]]; then
  printf '%s\n' "Invalid keyboard layout list" >&2
  exit 2
fi

if [[ ! "$variants" =~ ^[[:alnum:]_,-]*$ ]]; then
  printf '%s\n' "Invalid keyboard variant list" >&2
  exit 2
fi

if [[ ! "$active_index" =~ ^[0-9]+$ ]]; then
  printf '%s\n' "Invalid active layout index" >&2
  exit 2
fi

if [[ ! "$remap_b64" =~ ^[A-Za-z0-9+/=]*$ ]]; then
  printf '%s\n' "Invalid keyboard remap payload" >&2
  exit 2
fi

if [[ ! -f "$config" ]]; then
  printf '%s\n' "Hyprland input config not found: $config" >&2
  exit 1
fi

remap_body=""
if [[ -n "$remap_b64" ]]; then
  remap_body=$(base64 -d <<<"$remap_b64")
fi

# The remap symbols come from Model.js's curated KEY_TABLE, never free text,
# so this layout string is always safe to hand to xkbcli/Hyprland as-is.
#
# The component is prefixed to the first layout only, and the symbols file
# spells out all four XKB groups itself. Appending it per layout instead
# collides with the ":N" group suffix the XKB rules add to each element,
# collapsing every group into group 1 and losing the per-group layout names.
augmented_layouts="$layouts"
if [[ -n "$remap_body" ]]; then
  augmented_layouts="omarchy-keymaps(remap)+${layouts}"
fi

tmp=""
symbols_scratch=""
cleanup() {
  if [[ -n "$tmp" ]]; then rm -f "$tmp"; fi
  if [[ -n "$symbols_scratch" ]]; then rm -rf "$symbols_scratch"; fi
}
trap cleanup EXIT

# kb_options is never written by this plugin, only read, so that the keymap is
# validated against the options actually in force.
current_options=$(hyprctl getoption input:kb_options -j | jq -r '.str // ""')

if [[ -n "$remap_body" ]]; then
  # Validate against a scratch copy of the new symbols file, which shadows any
  # real one through --include, before touching anything real. A remap that
  # does not compile can then never leave the keyboard unusable.
  symbols_scratch=$(mktemp -d)
  mkdir -p "$symbols_scratch/symbols"
  {
    printf '%s\n' 'xkb_symbols "remap" {'
    printf '%s\n' "$remap_body"
    printf '%s\n' '};'
  } >"$symbols_scratch/symbols/omarchy-keymaps"
fi

compile_args=(--test --include-defaults
  --layout "$augmented_layouts" --variant "$variants" --options "$current_options")
if [[ -n "$symbols_scratch" ]]; then
  compile_args=(--include "$symbols_scratch" "${compile_args[@]}")
fi

# xkbcli only exits non-zero when the keymap cannot be built at all (a missing
# component, say); it recovers from a bad rule inside an included file and still
# reports success, so treat anything it logs as an error as a failure too.
validation=$(xkbcli compile-keymap "${compile_args[@]}" 2>&1 >/dev/null) || validation_failed=1
if [[ -n "${validation_failed:-}" ]] || [[ "$validation" == *ERROR* ]]; then
  printf '%s\n' "Could not validate the requested keyboard settings" >&2
  printf '%s\n' "$validation" >&2
  exit 1
fi

if [[ -n "$remap_body" ]]; then
  mkdir -p "$symbols_dir"
  mv "$symbols_scratch/symbols/omarchy-keymaps" "$symbols_file"
else
  # No remaps left: drop the generated file so nothing stale is reported back
  # to the UI, which reads its configured pairs straight out of it.
  rm -f "$symbols_file"
fi

tmp=$(mktemp "${config}.tmp.XXXXXX")

awk -v layouts="$augmented_layouts" -v variants="$variants" '
function indent(line, result) {
  result = line
  sub(/[^[:space:]].*/, "", result)
  return result
}

{
  if ($0 ~ /^[[:space:]]*kb_layout[[:space:]]*=/) {
    print indent($0) "kb_layout = \"" layouts "\",";
    has_layout = 1
    next
  }

  if ($0 ~ /^[[:space:]]*kb_variant[[:space:]]*=/) {
    print indent($0) "kb_variant = \"" variants "\",";
    has_variant = 1
    next
  }

  if ($0 ~ /^[[:space:]]*kb_options[[:space:]]*=/) {
    if (!has_layout) {
      print indent($0) "kb_layout = \"" layouts "\",";
      has_layout = 1
    }
    if (!has_variant) {
      print indent($0) "kb_variant = \"" variants "\",";
      has_variant = 1
    }
  }

  print
}

END {
  if (!has_layout || !has_variant) {
    print ""
    print "-- Managed by omarchy-keymaps."
    print "hl.config({"
    print "  input = {"
    if (!has_layout) print "    kb_layout = \"" layouts "\",";
    if (!has_variant) print "    kb_variant = \"" variants "\",";
    print "  },"
    print "})"
  }
}
' "$config" > "$tmp"

chmod --reference="$config" "$tmp"
mv "$tmp" "$config"
tmp=""

hyprctl reload >/dev/null

if [[ -n "$keyboard" ]]; then
  hyprctl switchxkblayout "$keyboard" "$active_index" >/dev/null || true
fi