#!/usr/bin/env bash

# ANSI Retro Tool (art) for Linux
# Version 2.0 (02 Jan 2026) - Blue Oak Model License 1.0.0
# Project page: https://640kb.neocities.org/apps/apps.html

# Notes: The "--fconvert" flag performs the same function as "--convert" but
#        adds special ANSI sequences (clear screen, position cursor) and a
#        standardized footer with viewing instructions.
#
#        This is a basic ANSI viewer. Some files may not display correctly.
#        It was created specifically to automate posting ANSI art to
#        ansi@happynetbox.com and to make files Linux-terminal compatible.

#        More info: https://640kb.neocities.org/ascii/art.hnb.html


if [ $# -eq 0 ]; then
    echo ""
    echo " .----------------------------------------------------------------------."
    echo " | ANSI Retro Tool (art)                                                |"
    echo " | ---------------------                                                |"
    echo " | A homemade ANSI Art viewer and CP437-to-UTF-8 converter built from   |"
    echo " | standard Linux tools:  iconv, sed, echo -e and cat                   |"
    echo " |                                                                      |"
    echo " | Usage: art [OPTION] <file.ans>                                       |"
    echo " |                                                                      |"
    echo " | Options:                                                             |"
    echo " |   --convert  Save converted UTF-8 version as <INPUT_FILE.converted>  |"
    echo " |                                                                      |"
    echo " |   --fconvert Preps ANSI for posting to .plan <INPUT_FILE.fconverted> |"
    echo " |              (adds clear screen, cursor positioning and footer)      |"
    echo " |                                                                      |"
    echo " |   --reset    Reset terminal colors and clear screen                  |"
    echo " |                                                                      |"
    echo " | Examples:                                                            |"
    echo " |   art (no options)         Display this help                         |"
    echo " |   art file.ans             Display ANSI Art to stdout                |"
    echo " |   art --convert file.ans   Generate file.ans.converted (UTF-8)       |"
    echo " |   art --fconvert file.ans  Generate file.ans.fconverted (UTF-8)      |"
    echo " |                            ready for posting                         |"
    echo " |                                                                      |"
    echo " | Note: ANSI files should be CP437 encoded for correct display         |"
    echo " '----------------------------------------------------------------------'"
    echo ""
    exit 1
fi

CONVERT_MODE=false
FCONVERT_MODE=false
INPUT_FILE=""

if [ "$1" = "--convert" ]; then
    CONVERT_MODE=true
    INPUT_FILE="$2"
elif [ "$1" = "--fconvert" ]; then
    FCONVERT_MODE=true
    INPUT_FILE="$2"
elif [ "$1" = "--reset" ]; then
    printf "\033c"
    exit 0
else
    INPUT_FILE="$1"
fi

if [ ! -f "$INPUT_FILE" ]; then
    echo "Error: File '$INPUT_FILE' not found!"
    exit 1
fi

TEMP_FILE=$(mktemp /tmp/ansi_converted_XXXXXX.txt)
if [ $? -ne 0 ]; then
    echo "Error: Could not create temporary file"
    exit 1
fi

if [ "$CONVERT_MODE" = true ]; then
    OUTPUT_FILE="${INPUT_FILE}.converted"
elif [ "$FCONVERT_MODE" = true ]; then
    OUTPUT_FILE="${INPUT_FILE}.fconverted"
else
    OUTPUT_FILE=""
fi

if [ -n "$OUTPUT_FILE" ] && [ -f "$OUTPUT_FILE" ] && { [ "$CONVERT_MODE" = true ] || [ "$FCONVERT_MODE" = true ]; }; then
    read -p "Overwrite existing file $OUTPUT_FILE? [y/N] " -n 1 -r
    echo ""
    if [[ ! $REPLY =~ ^[Yy]$ ]]; then
        echo "Conversion cancelled"
        rm -f "$TEMP_FILE"
        exit 0
    fi
fi

if ! iconv -f CP437 -t UTF-8//IGNORE "$INPUT_FILE" > "$TEMP_FILE"; then
    echo "Error: Conversion failed! Is iconv installed?"
    rm -f "$TEMP_FILE"
    exit 1
fi

sed -i 's/\x1b/\\e/g' "$TEMP_FILE"

if [ "$CONVERT_MODE" = true ]; then
    cp "$TEMP_FILE" "$OUTPUT_FILE"
    echo ""
    echo "Converted file saved as: $OUTPUT_FILE"
    echo ""
elif [ "$FCONVERT_MODE" = true ]; then
    TEMP_FCONVERT=$(mktemp /tmp/ansi_fconverted_XXXXXX.txt)
    
    printf '%s' '\e[2J\e[H\e[E\e[E' > "$TEMP_FCONVERT"
    
    cat "$TEMP_FILE" >> "$TEMP_FCONVERT"
    
    echo "-------------------------------------------------------------------------------" >> "$TEMP_FCONVERT"
    echo "* view: curl -s gopher://happynetbox.com:79/0ansi | head -n -2 | echo -e \"\$(cat)\"" >> "$TEMP_FCONVERT"
    echo "* info: https://640kb.neocities.org/ascii/art.hnb.html" >> "$TEMP_FCONVERT"
    echo '\e[s\e[3A\e[0J' >> "$TEMP_FCONVERT"
    
    cp "$TEMP_FCONVERT" "$OUTPUT_FILE"
    
    rm -f "$TEMP_FCONVERT"
    
    echo ""
    echo "F-Converted file saved as: $OUTPUT_FILE"
    echo ""
else
    echo ""
    echo -e "$(cat "$TEMP_FILE")"
    echo ""
fi

[ -f "$TEMP_FILE" ] && rm -f "$TEMP_FILE"