#!/usr/bin/bash

# Copyright 2024 Universal Blue
#
# This file includes code that is licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software distributed under the License is
# distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and limitations under the License.


##################################################################
# This is a helper script to provide a basic fallback replacement 
# for just commands and bash scripts that want to use gum in uBlue
##################################################################

# Supported menu handlers
SUPPORTED_HANDLERS=(
    "fzf"
)

# Check if gum is present
GUM=$(which gum 2>/dev/null)

# Check if fzf is installed and set it as the handler
FALLBACK_HANDLER=$(which fzf 2>/dev/null)
HANDLER=""
if [[ -n $FALLBACK_HANDLER ]]; then
    HANDLER="fzf"
fi

# If $MENU is set
if [[ -n $MENU ]]; then
    for BIN in "${SUPPORTED_HANDLERS[@]}"
    do
        if [[ "$BIN" == "$MENU" ]]; then
            HANDLER=$BIN
        fi
    done
fi

# Logic for what to do if gum is not installed
function noGum () {
    if [[ -z "$1" ]]; then
        # If no arguments are provided then error with 
        echo "ugum supports only choose or confirm as the first argument!"
        echo "Usage:"
        echo '    ugum choose option1 option2 \"option 3\"'
        echo '        Returns: selected string'
        echo '    ugum confirm "this is an optional question'
        echo '        Returns: exit code in $? will be 0 for YES and 1 for NO'
        exit 5
    elif [[ "$1" == "choose" ]]; then
        # If choose is the verb then run the choose function and pass all remaining args to an appropriate handler
        if [[ "$HANDLER" == "fzf" ]]; then
            # Use fzf for choice selector
            choose_Fzf "${@:2}"
        else
            # Use generic bash selector
            choose_Generic "${@:2}"
        fi
    elif [[ "$1" == "confirm" ]]; then
        # If confirm is the verb then run the confirm function and pass all remaining args to an appropriate handler
        if [[ "$HANDLER" == "fzf" ]]; then
            # Use fzf as a confirm dialog
            confirm_Fzf "${@:2}"
        else
            # Use a generic bash dialog
            confirm_Generic "${@:2}"
        fi
    fi
}

# Implements a generic bash choice dialog
function choose_Generic () {
    # Change PS3 to our select prompt
    PS3='Please enter your choice: '

    # Make an array to contain all options in
    OPTIONS=()

    # Parse the arguments for the ones we support and care about
    for arg in "$@"
    do
        # If the argument does not start with -
        if [[ ! $arg =~ ^- ]]; then
            OPTIONS+=("$arg")
        fi
    done

    # Make a select prompt in bash
    select opt in "${OPTIONS[@]}"
    do
        case $opt in
            "")
                # Invalid options print to STDERR and then loops back for the user to select again
                echo "Invalid option $REPLY" >&2
                ;;
            "$opt")
                echo "$opt"
                break
                ;;
        esac
    done 
}

# Implements a choice dialog using fzf
function choose_Fzf () {
    # Change our select prompt
    PROMPT='Please select your choice: '

    # Make an array to contain all options in
    local OPTIONS

    # Parse the arguments for the ones we support and care about
    for arg in "$@"
    do
        # If the argument does not start with -
        if [[ ! $arg =~ ^- ]]; then
            if [[ "$OPTIONS" == "" ]]; then
                OPTIONS="${arg}"
                continue
            fi
            OPTIONS="${OPTIONS}\n${arg}"
        fi
    done

    # Make a select prompt using fzf
    echo -e "$OPTIONS" | fzf --layout=reverse --height="~20%" --prompt="$PROMPT"
}

# Implements a generic bash confirm dialog
function confirm_Generic () {
    # Set default prompt
    PROMPT="Are you sure?"

    # Parse the arguments for the ones we support and care about 
    for arg in "$@"
    do
        if [[ ! $arg =~ ^- ]]; then
            PROMPT="$arg"
        fi
    done

    # Print the prompt and read input
    read -r -p "$PROMPT [Y/n]: " YESNO
    confirm_Parse "$YESNO"
}

# Implements a confirm dialog in fzf
function confirm_Fzf () {
    PROMPT=$(confirm_getPrompt "$@")

    # Make the confirm prompt using fzf and read response
    YESNO=$(echo -e "Yes\nNo" | fzf --layout=reverse --height="~20%" --prompt="$PROMPT ")
    confirm_Parse "$YESNO"
}

# Gets the prompt for the confirm dialog, with a fallback to "Are you sure?"
function confirm_getPrompt () {
    # Set default prompt
    PROMPT="Are you sure?"

    # Parse the arguments for the ones we support and care about 
    for arg in "$@"
    do
        if [[ ! $arg =~ ^- ]]; then
            PROMPT="$arg"
        fi
    done

    # Return the prompt
    echo "$PROMPT"
}

# Parse the confirm response and translate it the same exit codes gum uses
function confirm_Parse () {
    case "$@" in
        [Yy]*)
            # Use exit code 0 for yes, just like gum
            exit 0
            ;;
        [Nn]*)
            # Use exit code 1 for no, just like gum
            exit 1
            ;;
        *)
            # Default exit code is 0
            exit 0
            ;;
    esac
}

# If gum is not present
if [[ -z "$GUM" ]]; then
    noGum "$@"
else
    # If gum is present just pass args to gum
    $GUM "$@"
fi