#!/bin/sh

# Copyright (c) 2022–2023 Emma Tebibyte <emma@tebibyte.media>
# SPDX-License-Identifier: AGPL-3.0-or-later
#
# This program is free software: you can redistribute it and/or modify it under
# the terms of the GNU Affero General Public License as published by the Free
# Software Foundation, either version 3 of the License, or (at your option) any
# later version.
# 
# This program is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
# details.
#
# You should have received a copy of the GNU Affero General Public License along
# with this program. If not, see https://www.gnu.org/licenses/.

set -e

argv0="$0"

get_urls() {
  i="0"
  until ! tomcat replace.urls["$i"] "$file" >/dev/null 2>&1
  do
    URLS="$(printf "%s\n%s" \
      "$URLS" \
      "$(tomcat replace.urls["$i"] "$file")"
    )"

    i="$(printf "%s+1\n" "$i" | bc)"
  done
}

# check if usage is valid
if test -z "$1"; then
  printf "Usage: %s [resource...]\n" "$argv0" 1>&2
  exit 64 # sysexits(3) EX_USAGE
fi

for dep in \
  curl \
  handlr
do
  if ! command -v "$dep" >/dev/null 2>&1; then
    printf "%s: Missing dependency: %s(1)\n" "$argv0" "$dep" 1>&2
    exit 69 # sysexits(3) EX_UNAVAILABLE
  fi
done

# check if we have a BROWSER
if test -z "$BROWSER"; then
  printf "%s: \$BROWSER not filled.\n" "$argv0" 1>&2
  exit 71 # sysexits(3) EX_OSERR
fi

while test -n "$1"; do
  URL="$1"

  # use curl(1) to write out the request header's content_type, strip everything
  # after the first semicolon, chop off any weird whitespace remnants
  MIME="$(curl -Ls -o /dev/null -w '%{content_type}' "$1" | sed 's/\;.*//' \
    | xargs echo)"

  # get the URL with no scheme
  NO_SCHEME="$(printf "%s\n" "$URL" | sed -n 's/^h.\+\/\///p')"

  # get the pattern for the extensions to MATCH
  MATCH="$(printf "%s\n" "$NO_SCHEME" | sed 's/\/.*\+//g')"

  # get the non-domain of the URI for tacking onto the end of replaced URIs
  URI="$(printf "%s\n" "$NO_SCHEME" | sed -n 's/^[^/]*\///p')"
  
  # only check for extensions if tomcat(1) is installed
  if command -v tomcat >/dev/null 2>&1; then
    # run through MIME extensions
    for file in \
      "$XDG_DATA_HOME"/xdg-sanity/*.mime.toml \
      /usr/share/xdg-sanity/*.mime.toml \
      /usr/local/share/xdg-sanity/*.mime.toml
    do
      if test -e "$file"; then
        get_urls
        for url in $URLS; do
          if [ "$MATCH" = "$url" ]; then
            MIME="$(tomcat with.mime "$file")"
          fi
        done
      fi
    done

    # then replace extensions
    for file in \
      "$XDG_DATA_HOME"/xdg-sanity/*.replace.toml \
      /usr/share/xdg-sanity/*.replace.toml \
      /usr/local/share/xdg-sanity/*.replace.toml
    do
      if test -e "$file"; then
        get_urls
        for url in $URLS; do
          if [ "$MATCH" = "$url" ]; then
            URL="$(tomcat with.url "$file")$URI"
          fi
        done
      fi
    done

    # and the scheme extensions
    for file in \
      "$XDG_DATA_HOME"/xdg-sanity/*.scheme.toml \
      /usr/share/xdg-sanity/*.scheme.toml \
      /usr/local/share/xdg-sanity/*.scheme.toml
    do
      get_urls
      for url in $URLS; do
        if [ "$URL" = "$url" ]; then
          URL="$(tomcat with.scheme "$file")$MATCH"
        fi
      done
    done
  fi

  # these commands may fail; this is intentional
  if [ "$MIME" = "text/html" ]; then
    "$BROWSER" "$URL"
  else
    handlr launch "$MIME" -- "$URL"
  fi
  shift
done

exit 0