#!/usr/bin/env bash

set -euo pipefail

# Keep select menus one item per line for screen readers.
export COLUMNS=1

missingRequired=()
installPlan=()

add_missing_package() {
    local package="$1"
    local existing

    for existing in "${missingRequired[@]}"; do
        [[ "$existing" == "$package" ]] && return
    done
    missingRequired+=("$package")
}

add_install_package() {
    local package="$1"
    local existing

    for existing in "${installPlan[@]}"; do
        [[ "$existing" == "$package" ]] && return
    done
    installPlan+=("$package")
}

command_exists() {
    command -v "$1" &> /dev/null
}

python_import_works() {
    local code="$1"

    command_exists python3 && python3 -c "$code" &> /dev/null
}

has_any_command() {
    local commandName

    for commandName in "$@"; do
        if command_exists "$commandName"; then
            return 0
        fi
    done
    return 1
}

prompt_install() {
    local prompt="$1"
    shift
    local packages=("$@")
    local choice

    printf '%s\n' "$prompt"
    printf 'Packages: %s\n' "${packages[*]}"
    PS3="Select an option: "
    select choice in "Yes" "Exit installer"; do
        case "$choice" in
            "Yes")
                for package in "${packages[@]}"; do
                    add_install_package "$package"
                done
                return
                ;;
            "Exit installer")
                echo "Exiting without installing packages."
                exit 1
                ;;
            *)
                echo "Please choose 1 or 2."
                ;;
        esac
    done
}

install_packages() {
    if command_exists yay; then
        yay -S --needed "$@"
    else
        sudo pacman -S --needed "$@"
    fi
}

prompt_install_choice() {
    local prompt="$1"
    shift
    local choice
    local index
    local reply
    local options=("Skip" "$@" "Exit installer")
    local packages

    printf '%s\n' "$prompt"
    while true; do
        for index in "${!options[@]}"; do
            printf '%d) %s\n' "$((index + 1))" "${options[$index]}"
        done
        read -r -p "Select a package to install [1]: " reply
        if [[ -z "$reply" ]]; then
            reply=1
        fi
        if [[ ! "$reply" =~ ^[0-9]+$ ]] || (( reply < 1 || reply > ${#options[@]} )); then
            echo "Please choose a listed option."
            continue
        fi
        choice="${options[$((reply - 1))]}"
        case "$choice" in
            "Skip")
                return
                ;;
            "Exit installer")
                echo "Exiting without installing packages."
                exit 1
                ;;
            *)
                read -r -a packages <<< "$choice"
                for package in "${packages[@]}"; do
                    add_install_package "$package"
                done
                return
                ;;
        esac
    done
}

check_required_dependencies() {
    command_exists dialog || add_missing_package dialog
    command_exists i3 || add_missing_package i3-wm
    command_exists jq || add_missing_package jq
    command_exists python3 || add_missing_package python
    command_exists rsync || add_missing_package rsync
    command_exists yad || add_missing_package yad
    command_exists xdotool || add_missing_package xdotool
    command_exists xdg-open || add_missing_package xdg-utils

    if ! python_import_works 'import i3ipc'; then
        add_missing_package python-i3ipc
    fi

    if ! python_import_works 'import gi; gi.require_version("Atk", "1.0"); gi.require_version("Gdk", "3.0"); gi.require_version("Gio", "2.0"); gi.require_version("GLib", "2.0"); gi.require_version("Gtk", "3.0"); from gi.repository import Atk, Gdk, Gio, GLib, Gtk'; then
        add_missing_package python-gobject
    fi

    if ! command_exists pandoc && ! command_exists markdown; then
        add_missing_package discount
    fi
}

check_provider_dependencies() {
    local emailChoices=(thunderbird evolution)
    local browserChoices=(firefox chromium epiphany midori seamonkey vivaldi)
    local screenReaderChoices=(orca)

    if command_exists yay; then
        emailChoices+=(betterbird)
        browserChoices+=(brave-bin)
        screenReaderChoices+=(cthulhu)
    fi

    if ! has_any_command betterbird evolution thunderbird; then
        prompt_install_choice "Missing email client. Select one to install." "${emailChoices[@]}"
    fi

    if ! has_any_command brave chromium epiphany firefox google-chrome-stable google-chrome-unstable microsoft-edge-stable microsoft-edge-beta microsoft-edge-dev midori seamonkey vivaldi; then
        prompt_install_choice "Missing web browser. Select one to install." "${browserChoices[@]}"
    fi

    if ! has_any_command emacs geany gedit kate kwrite l3afpad leafpad libreoffice mousepad pluma; then
        prompt_install_choice "Missing graphical text editor. Select one to install." geany gedit kate kwrite l3afpad leafpad libreoffice-fresh mousepad pluma
    fi

    if ! has_any_command caja nemo nautilus pcmanfm pcmanfm-qt thunar; then
        prompt_install_choice "Missing file manager. Select one to install." pcmanfm thunar caja nemo nautilus pcmanfm-qt
    fi

    if ! has_any_command mate-terminal lxterminal gnome-terminal terminator xfce4-terminal tilix ptyxis kgx sakura roxterm termit guake tilda qterminal konsole && { ! command_exists xterm || ! command_exists fenrir; }; then
        prompt_install_choice "Missing supported accessible terminal. Select one to install." mate-terminal lxterminal gnome-terminal terminator xfce4-terminal tilix ptyxis kgx sakura qterminal konsole "xterm fenrir"
    fi

    if ! has_any_command cthulhu orca; then
        prompt_install_choice "Missing screen reader. Select one to install." "${screenReaderChoices[@]}"
    fi
}

add_optional_dependencies() {
    command_exists bc || add_install_package bc
    command_exists notify-send || add_install_package libnotify
    command_exists pamixer || add_install_package pamixer
    command_exists playerctl || add_install_package playerctl
    command_exists scrot || add_install_package scrot
    command_exists sox || add_install_package sox
    command_exists udiskie || add_install_package udiskie
    command_exists xclip || add_install_package xclip
    command_exists xprintidle || add_install_package xprintidle
    command_exists xset || add_install_package xorg-xset

    echo "Skipping optional packages that need manual choice or are intentionally not installed automatically:"
    echo "  dex"
    echo "  tesseract"
    echo "  xzoom"
}

if ! command_exists pacman && ! command_exists yay; then
    echo "This helper is for Arch Linux systems with pacman or yay."
    exit 1
fi

check_required_dependencies

if [[ ${#missingRequired[@]} -gt 0 ]]; then
    prompt_install "Missing required I38 dependencies. Add them to the install list?" "${missingRequired[@]}"
fi

check_provider_dependencies
add_optional_dependencies

if [[ ${#installPlan[@]} -gt 0 ]]; then
    echo "Installing selected packages:"
    printf '  %s\n' "${installPlan[@]}"
    install_packages "${installPlan[@]}"
else
    echo "No packages selected for installation."
fi

echo "I38 dependency check complete."