#!/bin/bash

NC='\033[0m'
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[0;33m'

BROWSER=`which firefox-bin`
BOOKMARKS=$HOME/.local/share/misc/bookmarks
HISTORY=$HOME/.cache/omnibar_hist.txt
ENGINE="https://search.dyamon.me/search?q=%s"

#URL_PATTERN='^(https?://)?([A-Za-z0-9-]+\.)+[A-Za-z0-9-]+(:[0-9]+)?(/[A-Za-z0-9%#.=-]*)*(\?([A-Za-z0-9-]+(=[A-Za-z0-9-]+)?&?)+)?$'
URL_PATTERN='^(https?://)?([A-Za-z0-9-]+\.)+[A-Za-z0-9-]+(:[0-9]+)?(/.*)?'

msg_info() {
    echo -e "${GREEN}[INFO] $1${NC}"
}

msg_warn() {
    echo -e "${YELLOW}[WARN] $1${NC}"
}

msg_error() {
    echo -e "${RED}[ERROR] $1${NC}"
}

print_help() {
    echo
    echo "dmenu_omnibar - a poor man's omnibar and bookmark manager (using dmenu)"
    echo
    echo "USAGE:"
    echo "    dmenu_omnibar -h|--help"
    echo "    dmenu_omnibar [-b|--browser <path>] [-B|--bookmarks <path>] [-s|--search-engine <url>]"
    echo
    echo "where:"
    echo "    -h | --help:"
    echo "        prints this help message."
    echo "    -b | --browser <path>"
    echo "        path to the executable used to open the selected link."
    echo "    -B | --bookmarks <path>"
    echo "        path to a file containing a list of bookmarks and"
    echo "        omnibar commands. See FORMAT below."
    echo "    -s | --search-engine <url>"
    echo "        default URL used when the input does not match any other"
    echo "        bookmark, URL or omnibar command. It should contain the"
    echo "        placeholder \"%s\" to be substituted with the query"
    echo "        provided by dmenu."
    echo
    echo "DMENU"
    echo "    dmenu will prompt for a bookmark from the provided list."
    echo "    If a match is found, the URL is selected. If a match is"
    echo "    not found the input is interpreted as follows:"
    echo "    1) as an URL if the provided input is an URL;"
    echo "    2) as a command if the input starts with \":\". Anything"
    echo "       following the command is interpreted as a query;"
    echo "    3) as a query to be submitted to the default search engine."
    echo 
    echo "    Note: sometimes an input partially matches an entry in the"
    echo "    bookmarks when you are aiming to one of the other behaviours"
    echo "    (e.g., opening an URL directly). You can submit only the"
    echo "    input text (without autoselection from the list of bookmarks)"
    echo "    with Shift-Enter."
    echo
    echo "COMMAND HISTORY"
    echo "    Rudimental support for command history is provided. Up to"
    echo "    10 unique entries will appear at the top of the dmenu"
    echo "    selection list."
    echo 
    echo "    The following internal commands are also supported:"
    echo "      !clear    clears the command history"
    echo 
    echo "    Prepending your dmenu entry with one or more whitespaces"
    echo "    (space or tab) disables saving the entry to history."
    echo
    echo "BOOKMARK FORMAT"
    echo "    The bookmarks file is assumed to have the following syntax."
    echo
    echo "    Lines containing a simple bookmark start with a sequence of"
    echo "    keywords, separated by one or more spaces, followed by the"
    echo "    URL of the bookmark."
    echo
    echo "    Lines containing omnibar commands start with a command"
    echo "    with a leading colon (e.g., \":s\", \":yt\") followed by"
    echo "    the URL containing the placeholder \"%s\" that will be"
    echo "    substituted with the provided query."
    echo
}

# Simple URL encoder
# The conversions are performed according to these tables
#
#   https://docs.microfocus.com/OMi/10.62/Content/OMi/ExtGuide/ExtApps/URL_encoding.htm
#   https://en.wikipedia.org/wiki/Percent-encoding#Reserved_characters
#
# Consider using something like this:
#
#   https://gist.github.com/cdown/1163649
#
# for a more reliable approach.
urlencode() {
    sed 's|+|%2b|g' | sed 's|/|%2f|g'
}

# Manage history
save_to_history() {
    # File might not exist
    touch "$HISTORY"
    # Add new entry at the top
    echo "🔍 $1" | cat - "$HISTORY" > "$HISTORY.tmp"
    # Remove duplicates and truncate file to 10 entries
    uniq "$HISTORY.tmp" | sed 11q > "$HISTORY"
}

clear_history() {
    shred -u "$HISTORY" "$HISTORY.tmp"
}

omnisearch() {
    [[ "$1" =~ ^[[:blank:]]+ ]] && anon=true || anon=false
    # Clean input
    input=$(echo -n "$1" | sed 's/^\s*//' | sed 's/^🔍\s*//' | sed 's/📋 \(primary\|clipboard\)\s*//')
    # Process input
    if [[ "$input" == "!clear" ]]
    then
        clear_history
    elif grep -qs "^$input$" "$BOOKMARKS"
    then
        # Bookmark
        echo "$input" | awk '{ print $(NF) }'
    elif [[ "$input" =~ $URL_PATTERN ]]
    then
        # URL
        echo "$input"
        $anon || save_to_history "$input" 
    elif [[ "$input" =~ :[a-z]+\ .* ]]
    then
        # Omnisearch command
        CMD=$(echo "$input" | cut -s -d' ' -f1 -)
        SEARCH=$(echo "$input" | cut -s --complement -d' ' -f1 - | urlencode)
        # NOTE: the space after `$CMD` in the following `grep` is
        # important to avoid multiple matches when having one command
        # being a leading substring of another.
        URL=$(grep "$CMD " "$BOOKMARKS" | awk '{ print $(NF) }' | sed "s/%s/$SEARCH/g")
        echo "$URL"
        $anon || save_to_history "$input" 
    else
        # Default search query
        SEARCH=$(echo "$input" | urlencode)
        echo "$ENGINE" | sed "s/%s/$SEARCH/g"
        $anon || save_to_history "$input" 
    fi
}

while [[ $# -gt 0 ]]; do
    arg="$1"
    case $arg in
        -h|--help)
            print_help
            exit 0
            ;;
        -b|--browser)
            if [[ $# -ge 2 ]]; then
                BROWSER=$2
                shift ; shift
            else
                msg_error "No value found for flag $arg!"
                print_help
                exit 2
            fi
            ;;
        -B|--bookmarks)
            if [[ $# -ge 2 ]]; then
                BOOKMARKS=$2
                shift ; shift
            else
                msg_error "No value found for flag $arg!"
                print_help
                exit 3
            fi
            ;;
        -s|--search-engine)
            if [[ $# -ge 2 ]]; then
                ENGINE="$2"
                shift ; shift
            else
                msg_error "No value found for flag $arg!"
                print_help
                exit 4
            fi
            ;;
        *)
            msg_error "$arg is not a valid flag!"
            print_help
            exit 1
            ;;
    esac
done

OPTIONS=""

# Primary selection
PRIMARY=$(xclip -out -selection primary 2>/dev/null | tr -d '\n')
[ -n "$PRIMARY" ] && \
    [[ "$PRIMARY" =~ $URL_PATTERN ]] && \
    OPTIONS="📋 primary               $PRIMARY\\n"

# Clipboard selection
CLIPBOARD=$(xclip -out -selection clipboard 2>/dev/null | tr -d '\n')
[ -n "$CLIPBOARD" ] && \
    [[ "$CLIPBOARD" =~ $URL_PATTERN ]] && \
    OPTIONS="${OPTIONS}📋 clipboard             $CLIPBOARD\\n"

OPTIONS=$(cat "$HISTORY" ; echo -ne "$OPTIONS" ; grep -v ^: "$BOOKMARKS")

URL=$(echo "$OPTIONS"  | dmenu -l 18 -h 23)
[ -z "$URL" ] && exit 0 || OMNIURL=$(omnisearch "$URL")

# Starts browser in background
[ -z "$OMNIURL" ] || "$BROWSER" "$OMNIURL" &