#!/bin/bash

DRY_RUN=false
DELETE=false

while [[ $# -gt 0 ]]; do
    case "$1" in
        --dry-run)
            DRY_RUN=true
            shift
            ;;
        --delete)
            DELETE=true
            shift
            ;;
        *)
            break
            ;;
    esac
done

if [[ $# -ne 1 ]]; then
    echo "Usage: $0 [--dry-run] [--delete] file.txt"
    exit 1
fi

list="$1"

while IFS= read -r file; do

    [[ -z "$file" ]] && continue

    if [[ ! -e "$file" ]]; then
        echo "ERROR: Missing file: $file"
        exit 1
    fi
    if [[ -d "$file" ]]; then
        echo "WARNING: Is a directory, skipping: $file"
        continue
    fi
    # Get comment from ID3v2
    comment=$(kid3-cli "$file" \
        -c "tag 2" \
        -c "get comment" 2>/dev/null)

    [[ -z "$comment" ]] && continue

    echo
    echo "File: $file"
    echo "Comment: $comment"

    composer=""

    # Match: read by Name; text
    if [[ "$comment" =~ ^[Rr]ead[[:space:]]+[Bb]y[[:space:]]+([^;]+)\; ]]; then
        composer="${BASH_REMATCH[1]}"
        composer="$(echo "$composer" | sed 's/[[:space:]]*$//')"

        echo "Found narrator: $composer"

        if $DRY_RUN; then
            echo "DRY RUN: set composer '$composer', delete comment"
        else
            kid3-cli "$file" \
                -c "tag 2" \
                -c "set composer '$composer'" \
                -c "set comment ''" \
                -c save
        fi

    elif [[ ${#comment} -lt 40 ]]; then

        echo "Short comment (${#comment} chars): $comment"

        if $DELETE; then
            if $DRY_RUN; then
                echo "DRY RUN: delete comment"
            else
                kid3-cli "$file" \
                    -c "tag 2" \
                    -c "set comment ''" \
                    -c save
            fi
        fi
    fi

done < "$list"