#!/bin/bash

# Function to show usage
show_usage() {
    echo "Usage: $0 [-d|--dry-run] <path_to_original_rom>"
    echo "Options:"
    echo "  -d, --dry-run    Show what would be patched without actually patching"
    exit 1
}

# Parse command line arguments
DRY_RUN=0
ORIGINAL_ROM=""

while [[ $# -gt 0 ]]; do
    case $1 in
        -d|--dry-run)
            DRY_RUN=1
            shift
            ;;
        *)
            ORIGINAL_ROM="$1"
            shift
            ;;
    esac
done

# Check if original ROM was provided
if [ -z "$ORIGINAL_ROM" ]; then
    show_usage
fi

PATCHES_DIR="./patches"
OUTPUT_DIR="./patched"

# Check if original ROM exists
if [ ! -f "$ORIGINAL_ROM" ]; then
    echo "Error: Original ROM file not found: $ORIGINAL_ROM"
    exit 1
fi

# Check if flips is installed (skip check in dry run)
if [ $DRY_RUN -eq 0 ]; then
    if ! command -v flips &> /dev/null; then
        echo "Error: flips is not installed or not in PATH"
        exit 1
    fi
fi

# Create output directory if it doesn't exist (skip in dry run)
if [ $DRY_RUN -eq 0 ]; then
    mkdir -p "$OUTPUT_DIR"
fi

echo "$([ $DRY_RUN -eq 1 ] && echo '[DRY RUN] ')Processing patches..."
echo

# Find all .bps files and extract week numbers
while IFS= read -r patch_file; do
    # Extract week number from filename
    if [[ $patch_file =~ Week([0-9]+)\.bps$ ]]; then
        week_num="${BASH_REMATCH[1]}"
        # Create zero-padded week number
        padded_week=$(printf "Week%03d.smc" "$week_num")
        output_file="$OUTPUT_DIR/$padded_week"
        
        if [ $DRY_RUN -eq 1 ]; then
            echo "[DRY RUN] Would patch: $patch_file"
            echo "[DRY RUN] Would create: $output_file"
            echo
        else
            echo "Patching: $patch_file -> $padded_week"
            
            # Apply patch using flips
            flips -a "$patch_file" "$ORIGINAL_ROM" "$output_file"
            
            # Check if patching was successful
            if [ $? -eq 0 ]; then
                echo "Successfully created $padded_week"
            else
                echo "Error patching $patch_file"
            fi
            echo
        fi
    else
        echo "Warning: Could not extract week number from filename: $patch_file"
    fi
done < <(find "$PATCHES_DIR" -type f -name "Week*.bps" | sort -V)

total_files=$(find "$PATCHES_DIR" -type f -name "Week*.bps" | wc -l)
echo "$([ $DRY_RUN -eq 1 ] && echo '[DRY RUN] ')Would create $total_files patched ROMs in $OUTPUT_DIR"