#!/usr/bin/env bash
set -euo pipefail

ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
OUT_DIR="$ROOT_DIR/tests/fixtures/generated"

mkdir -p "$OUT_DIR"

ffmpeg -y -hide_banner -loglevel error -f lavfi -i testsrc=size=128x72:rate=30 -f lavfi -i sine=frequency=1000:sample_rate=44100 -t 1 -c:v libx264 -pix_fmt yuv420p -c:a aac -movflags +faststart "$OUT_DIR/clean.mp4"
ffmpeg -y -hide_banner -loglevel error -f lavfi -i testsrc=size=128x72:rate=30 -f lavfi -i sine=frequency=1000:sample_rate=44100 -t 1 -c:v libx264 -pix_fmt yuv420p -c:a aac "$OUT_DIR/no_faststart.mp4"
ffmpeg -y -hide_banner -loglevel error -f lavfi -i testsrc=size=128x72:rate=30 -t 1 -c:v libx264 -pix_fmt yuv420p "$OUT_DIR/video_only.mp4"
ffmpeg -y -hide_banner -loglevel error -f lavfi -i sine=frequency=1000:sample_rate=44100 -t 1 -c:a aac "$OUT_DIR/audio_only.mp4"
ffmpeg -y -hide_banner -loglevel error -f lavfi -i testsrc=size=128x72:rate=30 -f lavfi -i sine=frequency=1000:sample_rate=44100 -t 1 -c:v libx264 -pix_fmt yuv420p -c:a aac "$OUT_DIR/clean.mkv"

# Create a truncated file to simulate partial download/corruption
cp "$OUT_DIR/clean.mp4" "$OUT_DIR/truncated.mp4"
python3 - <<PY
import os
path = "$OUT_DIR/truncated.mp4"
size = os.path.getsize(path)
with open(path, "r+b") as f:
    f.truncate(max(0, size - 2048))
PY

# Heavier truncation for more pronounced errors
cp "$OUT_DIR/clean.mp4" "$OUT_DIR/truncated_hard.mp4"
python3 - <<PY
import os
path = "$OUT_DIR/truncated_hard.mp4"
size = os.path.getsize(path)
with open(path, "r+b") as f:
    f.truncate(max(0, size // 2))
PY

# Corrupt bytes in the middle of the file
cp "$OUT_DIR/clean.mp4" "$OUT_DIR/corrupt_mid.mp4"
python3 - <<PY
import os
path = "$OUT_DIR/corrupt_mid.mp4"
with open(path, "r+b") as f:
    f.seek(0, os.SEEK_END)
    size = f.tell()
    if size > 4096:
        f.seek(size // 2)
        chunk = bytearray(f.read(1024))
        for i in range(len(chunk)):
            chunk[i] ^= 0xFF
        f.seek(size // 2)
        f.write(chunk)
PY

echo "Fixtures written to $OUT_DIR"