#!/usr/bin/env bash
# Copy photos and convert videos from upload/ into app/images/ (gallery source).
# Videos are always re-encoded for browser playback (H.264 + AAC, yuv420p, faststart).
#
# Usage (from app/):
#   ./scripts/sync-media.sh
#   UPLOAD_DIR=/upload IMAGES_DIR=/app/images ./scripts/sync-media.sh
#
# Requires: ffmpeg (for videos)

set -euo pipefail

upload_dir="${UPLOAD_DIR:-../upload}"
images_dir="${IMAGES_DIR:-images}"
dry_run=0
force=0
max_width=1920
crf=23
preset=medium

usage() {
	sed -n '2,8p' "$0"
	echo ""
	echo "Options:"
	echo "  --upload-dir DIR     Raw media source (default: ../upload)"
	echo "  --images-dir DIR     Gallery output (default: images)"
	echo "  --dry-run            Print actions only"
	echo "  --force              Re-copy / re-encode even if output looks up to date"
	echo "  --max-width N        Scale down wide video (default: 1920)"
	echo "  --crf N              H.264 quality (default: 23)"
	echo "  -h, --help           Show this help"
}

while [[ $# -gt 0 ]]; do
	case "$1" in
		--upload-dir) upload_dir=$2; shift 2 ;;
		--images-dir) images_dir=$2; shift 2 ;;
		--dry-run) dry_run=1; shift ;;
		--force) force=1; shift ;;
		--max-width) max_width=$2; shift 2 ;;
		--crf) crf=$2; shift 2 ;;
		-h | --help) usage; exit 0 ;;
		*) echo "Unknown option: $1" >&2; usage; exit 1 ;;
	esac
done

if ! command -v ffmpeg >/dev/null 2>&1; then
	echo "ffmpeg is required." >&2
	exit 1
fi

if [[ ! -d "$upload_dir" ]]; then
	echo "Upload directory not found: $upload_dir" >&2
	exit 1
fi

mkdir -p "$images_dir"

is_video_ext() {
	case "${1,,}" in
		.mp4 | .mov | .webm) return 0 ;;
		*) return 1 ;;
	esac
}

is_jpeg_ext() {
	case "${1,,}" in
		.jpg | .jpeg) return 0 ;;
		*) return 1 ;;
	esac
}

skip_name() {
	local base=${1##*/}
	[[ "$base" == .* ]] && return 0
	[[ "$base" == *.web.mp4 ]] && return 0
	[[ "$base" == *.converting.mp4 ]] && return 0
	[[ "$base" == *.part ]] && return 0
	return 1
}

skip_path() {
	case "$1" in
		*/thumbs/* | */hero/*) return 0 ;;
	esac
	return 1
}

needs_convert() {
	local src=$1 dst=$2
	if [[ -f "$dst" ]] && [[ "$force" -eq 0 ]] && [[ "$dst" -nt "$src" ]]; then
		return 1
	fi
	return 0
}

copy_one() {
	local src=$1 dst=$2 rel
	rel=${src#"$upload_dir"/}
	rel=${rel#/}
	echo "→ copy $rel"

	if [[ "$dry_run" -eq 1 ]]; then
		echo "  would write: ${dst#"$images_dir"/}"
		return 0
	fi

	mkdir -p "$(dirname "$dst")"
	cp -p "$src" "$dst"
	echo "  wrote: ${dst#"$images_dir"/}"
}

convert_one() {
	local src=$1 dst=$2
	local dir name tmp rel
	dir=$(dirname "$dst")
	name=$(basename "$dst" .mp4)
	tmp="$dir/.${name}.converting.mp4"
	rel=${src#"$upload_dir"/}
	rel=${rel#/}

	echo "→ convert $rel"

	if [[ "$dry_run" -eq 1 ]]; then
		echo "  would write: ${dst#"$images_dir"/}"
		return 0
	fi

	mkdir -p "$dir"
	rm -f "$tmp"
	trap 'rm -f "$tmp"' RETURN

	ffmpeg -nostdin -hide_banner -loglevel error -y \
		-i "$src" \
		-vf "scale=min(${max_width}\\,iw):-2" \
		-c:v libx264 -profile:v high -level:v 4.0 -pix_fmt yuv420p \
		-crf "$crf" -preset "$preset" \
		-c:a aac -b:a 128k -ac 2 \
		-movflags +faststart \
		-f mp4 \
		"$tmp"

	mv -f "$tmp" "$dst"
	trap - RETURN
	echo "  wrote: ${dst#"$images_dir"/}"
}

copied=0
converted=0
skipped=0

while IFS= read -r -d '' src; do
	base=$(basename "$src")
	ext=".${base##*.}"

	if skip_name "$base" || skip_path "$src"; then
		continue
	fi

	rel=${src#"$upload_dir"/}
	rel=${rel#/}
	dst="$images_dir/$rel"

	if is_jpeg_ext "$ext"; then
		if [[ -f "$dst" ]] && [[ "$force" -eq 0 ]] && [[ "$dst" -nt "$src" ]]; then
			((skipped++)) || true
			continue
		fi
		copy_one "$src" "$dst"
		((copied++)) || true
		continue
	fi

	if ! is_video_ext "$ext"; then
		continue
	fi

	dst="$images_dir/${rel%.*}.mp4"

	if ! needs_convert "$src" "$dst"; then
		((skipped++)) || true
		continue
	fi

	convert_one "$src" "$dst"
	((converted++)) || true
done < <(find "$upload_dir" -type f \( -iname '*.jpg' -o -iname '*.jpeg' -o -iname '*.mov' -o -iname '*.mp4' -o -iname '*.webm' \) -print0)

echo ""
echo "Done. Copied: $copied, converted: $converted, skipped: $skipped."
if [[ "$dry_run" -eq 1 ]]; then
	echo "(dry run — no files changed)"
fi