#!/bin/bash
# Generate emergency slate video + pre-rendered HLS segments for failover.
# Output: data/slate/ (slate MP4 + HLS segments + manifest)
# Requires: ffmpeg
set -e

SLATE_DIR="${1:-data/slate}"
mkdir -p "$SLATE_DIR"

SLATE_MP4="$SLATE_DIR/slate.mp4"
SLATE_HLS="$SLATE_DIR/hls"
mkdir -p "$SLATE_HLS"

echo "=== Generating Emergency Slate ==="

# 1. Generate 10s slate video: color bars + "We'll Be Right Back" text
echo "[1/3] Generating slate video (10s, H.264/AAC, 30fps, 2s keyframes)..."
ffmpeg -y -f lavfi -i "color=c=#1a1a2e:s=1280x720:d=10:r=30" \
       -f lavfi -i "sine=frequency=440:duration=10" \
       -filter_complex "[0]drawtext=text='Linear Void':fontcolor=#587792:fontsize=60:x=(w-text_w)/2:y=(h-text_h)/2-40,drawtext=text='We'\''ll Be Right Back':fontcolor=#ede8e6:fontsize=36:x=(w-text_w)/2:y=(h-text_h)/2+30[bg];[1]volume=0.15[a]" \
       -map "[bg]" -map "[a]" \
       -c:v libx264 -preset medium -crf 21 \
       -r 30 -g 60 -keyint_min 60 -sc_threshold 0 \
       -pix_fmt yuv420p \
       -c:a aac -b:a 128k -ar 48000 -ac 2 \
       -movflags +faststart \
       -t 10 \
       "$SLATE_MP4"

echo "   Slate MP4: $(du -h "$SLATE_MP4" | cut -f1)"

# 2. Verify slate meets normalization profile
echo "[2/3] Verifying slate normalization..."
ffprobe -v error -show_entries stream=codec_name,width,height,r_frame_rate,pix_fmt,sample_rate \
        -of default=noprint_wrappers=1 "$SLATE_MP4" 2>&1 | head -10

# 3. Package as pre-rendered HLS (fMP4, 6s segments)
echo "[3/3] Packaging as HLS..."
ffmpeg -y -i "$SLATE_MP4" \
       -c copy \
       -f hls \
       -hls_time 6 \
       -hls_list_size 5 \
       -hls_segment_type fmp4 \
       -hls_fmp4_init_filename "init.mp4" \
       -hls_flags "independent_segments" \
       -hls_segment_filename "$SLATE_HLS/slate_segment_%03d.m4s" \
       "$SLATE_HLS/slate.m3u8"

echo ""
echo "=== Slate Generated ==="
echo "  MP4:      $SLATE_MP4"
echo "  Manifest: $SLATE_HLS/slate.m3u8"
echo "  Segments: $(find "$SLATE_HLS" -name '*.m4s' | wc -l) files"
echo "  Init:     $SLATE_HLS/init.mp4"
echo ""
echo "To use: mount $SLATE_HLS as /app/slate in playout container"