#!/bin/bash

# omarchy:summary=Create a desktop launcher for a web app
# omarchy:args=[name url icon-url-or-name [custom-exec] [mime-types]]

set -e

ICON_DIR="$HOME/.local/share/icons/hicolor/256x256/apps"

safe_icon_name() {
  printf '%s\n' "$1" \
    | tr '[:upper:]' '[:lower:]' \
    | sed 's/[^[:alnum:]]\+/-/g; s/^-//; s/-$//'
}

require_plain_name() {
  # The name becomes a filename. A slash would turn it into directory levels, so
  # the launcher lands somewhere omarchy-webapp-remove cannot address and the app
  # is stuck in the launcher; a leading ../ leaves the applications directory
  # altogether. Refuse rather than silently renaming what the user typed -- most
  # often it is a URL entered in the name field.
  if [[ $1 == */* ]]; then
    echo "App name cannot contain '/': $1"
    exit 1
  fi
}

icon_name_from_ref() {
  local ref="$1"
  local name
  name=$(basename "$ref")

  if [[ $name == *.* ]]; then
    safe_icon_name "${name%.*}"
  else
    printf '%s\n' "$name"
  fi
}

install_user_icon() {
  local source="$1"
  local name="$2"
  local ext="${source##*.}"

  [[ $ext == "$source" ]] && ext="png"
  mkdir -p "$ICON_DIR"
  cp "$source" "$ICON_DIR/$name.$ext"
  gtk-update-icon-cache "$HOME/.local/share/icons/hicolor" &>/dev/null || true
  printf '%s\n' "$name"
}

download_icon() {
  curl -fsSL --max-time 10 -o "$2" "$1" 2>/dev/null &&
    [[ -s $2 && $(file -b --mime-type "$2") == image/* ]]
}

# Chromium --app= treats javascript:, file:, and data: as a document to
# run. Prefix schemeless input with https as before, then refuse anything
# that is not http(s).
normalize_webapp_url() {
  local url=$1
  if [[ ! $url =~ ^[a-zA-Z][a-zA-Z0-9+.-]*: ]]; then
    url="https://$url"
  fi
  printf '%s' "$url"
}

# Raw whitespace must be percent-encoded in a URL. Refuse it before serializing
# the desktop entry; before Exec argument quoting, it also split browser flags
# and additional URLs into separate arguments. Schemes are case-insensitive.
require_http_url() {
  local url=$1

  if [[ $url =~ [[:space:]] ]]; then
    echo "Error: web app URL must not contain whitespace." >&2
    exit 1
  fi

  if [[ ! ${url,,} =~ ^https?:// ]]; then
    echo "Error: web app URL must be http or https." >&2
    exit 1
  fi
}

fetch_site_icon() {
  local site_url="$1" dest="$2"
  local origin page icon_url
  origin=$(sed -E 's|^(https?://[^/]+).*|\1|' <<<"$site_url")

  # Prefer the site's own high-res icon (apple-touch-icon is typically 180px+),
  # then the well-known path, then Google's favicon service as a last resort.
  page=$(curl -fsSL --max-time 5 "$site_url" 2>/dev/null | head -c 100000 | tr '\n' ' ')
  icon_url=$(grep -oiE "<link[^>]*rel=[\"'][^\"']*apple-touch-icon[^\"']*[\"'][^>]*>" <<<"$page" |
    grep -oiE "href=[\"'][^\"']+" | head -1 | sed -E "s/^href=[\"']//")

  case $icon_url in
  http://* | https://*) ;;
  //*) icon_url="https:$icon_url" ;;
  /*) icon_url="$origin$icon_url" ;;
  ?*) icon_url="$origin/$icon_url" ;;
  esac

  { [[ -n $icon_url ]] && download_icon "$icon_url" "$dest"; } ||
    download_icon "$origin/apple-touch-icon.png" "$dest" ||
    download_icon "https://www.google.com/s2/favicons?domain=${site_url}&sz=256" "$dest"
}

desktop_string_escape() {
  # Desktop Entry "string" value (freedesktop Desktop Entry Spec, "Value types"):
  # a raw newline would start a new key line and let a value inject a second
  # Exec=. Escape backslash first, then tab/CR/LF and a leading space. Every value
  # written into the .desktop file passes through here.
  #
  # Parameter expansion rather than sed: GNU sed's N auto-prints the pattern space
  # and exits at end of input, so a `:a;N;$!ba` slurp skips every following s///
  # for a value with no newline in it - which is every value except the injection
  # attempt this exists to stop.
  local value="$1"

  value=${value//\\/\\\\}
  value=${value//$'\t'/\\t}
  value=${value//$'\r'/\\r}
  value=${value//$'\n'/\\n}
  [[ $value == " "* ]] && value="\\s${value# }"

  printf '%s' "$value"
}

desktop_exec_arg() {
  # One Exec argument, double-quoted per the freedesktop Exec spec: inside quotes
  # " ` $ \ take a backslash and a literal % becomes %%. Only the default Exec's
  # URL needs this; $CUSTOM_EXEC stays a whole command line (file-syntax only).
  local escaped
  escaped=$(printf '%s' "$1" \
    | sed -e 's/\\/\\\\/g' -e 's/"/\\"/g' -e 's/`/\\`/g' -e 's/\$/\\$/g' -e 's/%/%%/g')
  printf '"%s"' "$escaped"
}

if (( $# < 3 )); then
  echo -e "\e[32mLet's create a new web app you can start with the app launcher.\n\e[0m"
  APP_NAME=$(gum input --prompt "Name> " --placeholder "My favorite web app")
  require_plain_name "$APP_NAME"
  APP_URL=$(gum input --prompt "URL> " --placeholder "https://example.com")
  APP_URL=$(normalize_webapp_url "$APP_URL")
  require_http_url "$APP_URL"

  # Try to fetch the site's icon automatically first.
  mkdir -p "$ICON_DIR"
  ICON_VALUE=$(safe_icon_name "$APP_NAME")
  if fetch_site_icon "$APP_URL" "$ICON_DIR/$ICON_VALUE.png"; then
    gtk-update-icon-cache "$HOME/.local/share/icons/hicolor" &>/dev/null || true
    ICON_REF="$ICON_VALUE"
  else
    ICON_REF=$(gum input --prompt "Icon URL/name> " --placeholder "Could not fetch favicon automatically. Enter PNG icon URL or icon name")
  fi

  CUSTOM_EXEC=""
  MIME_TYPES=""
  INTERACTIVE_MODE=true
else
  APP_NAME="$1"
  APP_URL=$(normalize_webapp_url "$2")
  require_http_url "$APP_URL"
  ICON_REF="$3"
  CUSTOM_EXEC="$4" # Optional custom exec command
  MIME_TYPES="$5"  # Optional mime types
  INTERACTIVE_MODE=false
fi

# Ensure valid execution
if [[ -z $APP_NAME || -z $APP_URL ]]; then
  echo "You must set app name and app URL!"
  exit 1
fi

require_plain_name "$APP_NAME"

if [[ -z $ICON_REF ]]; then
  ICON_VALUE=$(safe_icon_name "$APP_NAME")
  mkdir -p "$ICON_DIR"
  if ! fetch_site_icon "$APP_URL" "$ICON_DIR/$ICON_VALUE.png"; then
    echo "Error: Failed to download icon."
    exit 1
  fi
  gtk-update-icon-cache "$HOME/.local/share/icons/hicolor" &>/dev/null || true
elif [[ $ICON_REF =~ ^https?:// ]]; then
  ICON_VALUE=$(safe_icon_name "$APP_NAME")
  mkdir -p "$ICON_DIR"
  if ! download_icon "$ICON_REF" "$ICON_DIR/$ICON_VALUE.png"; then
    echo "Error: Failed to download icon."
    exit 1
  fi
  gtk-update-icon-cache "$HOME/.local/share/icons/hicolor" &>/dev/null || true
elif [[ -f $ICON_REF ]]; then
  ICON_VALUE=$(install_user_icon "$ICON_REF" "$(safe_icon_name "$APP_NAME")")
else
  # Bundled Omarchy icons are package-owned under /usr/share/icons/hicolor.
  # Accept either "HEY" or the historical "HEY.png" argument form.
  ICON_VALUE=$(icon_name_from_ref "$ICON_REF")
fi

# Default Exec quotes the URL as one Exec-spec argument; the whole line then gets
# the file-syntax escaping below (unescaped first at read time per spec, so the
# layers compose). $CUSTOM_EXEC is a full command line, so it gets file-syntax only.
if [[ -n $CUSTOM_EXEC ]]; then
  EXEC_COMMAND=$CUSTOM_EXEC
else
  EXEC_COMMAND="omarchy-launch-webapp $(desktop_exec_arg "$APP_URL")"
fi

# Create application .desktop file
DESKTOP_DIR="$HOME/.local/share/applications"
DESKTOP_FILE="$DESKTOP_DIR/$APP_NAME.desktop"
mkdir -p "$DESKTOP_DIR"

name_field=$(desktop_string_escape "$APP_NAME")
exec_field=$(desktop_string_escape "$EXEC_COMMAND")
icon_field=$(desktop_string_escape "$ICON_VALUE")

cat >"$DESKTOP_FILE" <<EOF
[Desktop Entry]
Version=1.0
Name=$name_field
Comment=$name_field
Exec=$exec_field
Terminal=false
Type=Application
Icon=$icon_field
StartupNotify=true
EOF

# Add mime types if provided
if [[ -n $MIME_TYPES ]]; then
  printf 'MimeType=%s\n' "$(desktop_string_escape "$MIME_TYPES")" >>"$DESKTOP_FILE"
fi

chmod +x "$DESKTOP_FILE"

if [[ $INTERACTIVE_MODE == "true" ]]; then
  echo -e "You can now find $APP_NAME using the app launcher (SUPER + SPACE)\n"
fi