#!/bin/bash

# function to convert to snake_case
to_snake_case() {
    echo "$1" | tr '[:upper:]' '[:lower:]' | \
    sed -e 's/[^a-zA-Z0-9]/_/g' -e 's/__*/_/g' -e 's/^_//' -e 's/_$//'
}

# function to sanitize text for ImageMagick
sanitize() {
    echo "$1" | sed 's/"/\\"/g'
}

# function to truncate text
truncate_text() {
    local text="$1"
    if [ ${#text} -gt 50 ]; then
        echo "${text:0:47}..."
    else
        echo "$text"
    fi
}

# function to process title - remove everything before the - if it exists
process_title() {
    local title="$1"
    if [[ "$title" == *-* ]]; then
        title=$(echo "$title" | sed 's/^.*- *//')
    fi
    echo "$title"
}

# get the title to check if file exists
echo "Checking metadata..."
TITLE=$(yt-dlp --get-title "$1")
TITLE=$(process_title "$TITLE")
TITLE_TRUNCATED=$(truncate_text "$TITLE")
FILENAME=$(to_snake_case "$TITLE_TRUNCATED")

# check if file exists
if [ -f "${FILENAME}.mp4" ]; then
    echo "Error: ${FILENAME}.mp4 already exists"
    exit 1
fi

# download audio
echo "Downloading audio..."
yt-dlp -f bestaudio --extract-audio --audio-format mp3 --output "temp_audio.%(ext)s" --print-json "$1" > metadata.json 2>/dev/null
ARTIST=$(cat metadata.json | jq -r '.uploader')
YEAR=$(cat metadata.json | jq -r '.upload_date[0:4]')
DURATION=$(cat metadata.json | jq -r '.duration')
rm metadata.json

# format duration to MM:SS
DURATION_FORMATTED=$(printf "%02d:%02d" $((DURATION/60)) $((DURATION%60)))

# download thumbnail
echo "Downloading thumbnail..."
yt-dlp --write-thumbnail --skip-download --convert-thumbnails jpg "$1" -o "temp_thumb" 2>/dev/null

# create title card using the external script
echo "Generating title card..."
./create_title_card.sh temp_thumb.jpg "$(sanitize "$TITLE_TRUNCATED")" "$(sanitize "$ARTIST")" "$YEAR" "$DURATION_FORMATTED"

# create MP4 with title card and audio
echo "Creating final video..."
ffmpeg -loop 1 -i output_title_card.png -i temp_audio.mp3 \
    -c:v libx264 -preset ultrafast -tune stillimage \
    -c:a aac -b:a 192k -pix_fmt yuv420p \
    -shortest \
    -movflags +faststart \
    "${FILENAME}.mp4" 2>/dev/null

# clean up temporary files
rm temp_thumb.jpg output_title_card.png temp_audio.mp3

echo "Done! Created ${FILENAME}.mp4"