#!/usr/bin/env bash

set -euo pipefail
shopt -s nullglob nocaseglob

convert_one() {
    local src="$1"

    if [[ ! -f "$src" ]]; then
        echo "ERROR: file not found: $src"
        return 1
    fi

    local base="${src%.*}"
    local dst="${base}.jpg"
    local tmp="${base}.tmp.jpg"

    echo "Converting: $src"

    # Convert HEIC -> JPEG
    if ! magick "$src" \
        -auto-orient \
        -quality 100 \
        -sampling-factor 4:4:4 \
        "jpg:$tmp"; then
        echo "ERROR: conversion failed: $src"
        rm -f "$tmp"
        return 1
    fi

    # Verify JPEG exists and is not empty
    if [[ ! -s "$tmp" ]]; then
        echo "ERROR: output JPEG is empty: $tmp"
        rm -f "$tmp"
        return 1
    fi

    echo "Copying metadata..."

    # Copy all metadata from HEIC
    if ! exiftool \
        -overwrite_original \
        -TagsFromFile "$src" \
        -all:all \
        -unsafe \
        "$tmp" >/dev/null; then
        echo "ERROR: metadata copy failed: $src"
        rm -f "$tmp"
        return 1
    fi

    # Preserve filesystem timestamps
    touch -r "$src" "$tmp"

    # Replace existing JPEG atomically
    mv -f "$tmp" "$dst"

    # Final verification
    if [[ ! -s "$dst" ]]; then
        echo "ERROR: final JPEG missing: $dst"
        return 1
    fi

    # Delete original only after success
    rm -f "$src"

    echo "Done: $dst"
    echo "Removed: $src"
}

if [[ $# -gt 0 ]]; then
    convert_one "$1"
else
    files=( *.heic *.HEIC )

    if [[ ${#files[@]} -eq 0 ]]; then
        echo "No HEIC files found."
        exit 0
    fi

    for f in "${files[@]}"; do
        convert_one "$f"
    done
fi