#!/usr/bin/env bash

# Source the script 'common-functions.sh'.
SCRIPT_DIR=$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" &>/dev/null && pwd)
ROOT_DIR=$(grep --only-matching "^.*scripts[^/]*" <<<"$SCRIPT_DIR")
source "$ROOT_DIR/common-functions.sh"

_main() {
    local input_files=""
    local output_dir=""

    # Execute initial checks.
    _check_dependencies ""
    input_files=$(_get_files "par_type=file; par_validate_conflict=true")

    local dependencies=""
    dependencies=$(_get_dependencies "$input_files")
    _check_dependencies "$dependencies"
    _display_wait_box "2"
    output_dir=$(_get_output_dir "par_use_same_dir=true")

    export -f _get_command _run_command

    # Execute the function '_main_task' for each file in parallel.
    _run_task_parallel "$input_files" "$output_dir"
    _display_result_box "$output_dir"
}

_main_task() {
    local input_file=$1
    local output_dir=$2
    local output_file=""

    # Run the main process.
    local command=""
    command=$(_get_command "$input_file")
    _run_command "$input_file" "$command" "$output_dir"
}

_get_dependencies() {
    local input_files=$1
    local dependencies=""

    # Check dependencies for each file.
    for input_file in $input_files; do
        local command=""
        command=$(_get_command "$input_file")

        case $command in
        "libreoffice_writer")
            if ! _command_exists "libreoffice.writer" && ! _command_exists "libreoffice-writer"; then
                dependencies+="package=libreoffice-writer"
            fi
            ;;
        "pandoc") dependencies+="command=pandoc" ;;
        esac
        dependencies+=$'\n'
    done

    printf "%s" "$dependencies"
}

_get_command() {
    local input_file=$1
    local command=""

    case "${input_file,,}" in
    *.doc | *.docx) command="libreoffice_writer" ;;
    *.htm | *.html) command="libreoffice_writer" ;;
    *.odf | *.fodf) command="libreoffice_writer" ;;
    *.odt | *.fodt) command="libreoffice_writer" ;;
    *.rtf) command="libreoffice_writer" ;;
    *) command="pandoc" ;;
    esac

    printf "%s" "$command"
}

_run_command() {
    local input_file=$1
    local command=$2
    local output_dir=$3
    local output_format="odt"

    output_file=$(_get_output_filename "$input_file" "$output_dir" "par_extension_opt=replace; par_extension=$output_format")

    # Run the main process.
    case $command in
    "libreoffice_writer")
        # NOTE: Workaround to fix the bug 37531 in LibreOffice.
        # See the: https://bugs.documentfoundation.org/show_bug.cgi?id=37531
        local temp_file=""
        temp_file=$(_get_temp_file_dry)

        # NOTE: LibreOffice does not support ' -- ' in the command line.
        # NOTE: LibreOffice does not support defining the output file manually.
        std_output=$(libreoffice --headless --convert-to "$output_format" "-env:UserInstallation=file://$temp_file" --outdir "$output_dir" "$input_file" 2>&1)
        _check_output "$?" "$std_output" "$input_file" ""

        # Remove the temporary file.
        rm -f -- "$temp_file"
        ;;
    "pandoc")
        std_output=$(pandoc --standalone -o "$output_file" -- "$input_file" 2>&1)
        _check_output "$?" "$std_output" "$input_file" "$output_file"
        ;;
    esac
}

_main "$@"