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

# -------- Defaults --------
LANGUAGE="en"
MODEL="medium"
OUTPUT_FORMAT="txt"     # txt|vtt|srt|json|tsv|lrc|all
WHISPER_EXEC=""

# -------- Usage --------
usage() {
  cat >&2 <<EOF
Usage:
  $0 <file.mp3|file.mp4|URL> [--language <code>] [--model <name>] [--output_format <fmt>]

Options:
  --language <code>       ISO code (default: ${LANGUAGE})
  --model <name>          whisper model name (default: ${MODEL})
  --output_format <fmt>   One of: txt|vtt|srt|json|tsv|lrc|all (default: ${OUTPUT_FORMAT})
  -h, --help              Show this help

Notes:
  - Input may be a local .mp3/.mp4 file or an http(s) URL to .mp3/.mp4
  - .mp4 will be transcoded to .mp3 via ffmpeg
EOF
}

# -------- Arg check --------
[[ $# -lt 1 ]] && { usage; exit 1; }

INPUT="$1"; shift

# -------- Parse flags --------
while [[ $# -gt 0 ]]; do
  case "$1" in
    --language)       LANGUAGE="${2:-}"; shift 2 ;;
    --model)          MODEL="${2:-}";    shift 2 ;;
    --output_format)  OUTPUT_FORMAT="${2:-}"; shift 2 ;;
    -h|--help)        usage; exit 0 ;;
    *) echo "Unknown option: $1" >&2; usage; exit 1 ;;
  esac
done

# -------- Validate deps --------
need() { command -v "$1" >/dev/null 2>&1 || { echo "Missing dependency: $1" >&2; exit 1; }; }
need ffmpeg
need wget

# Prefer PATH whisper; fallback to $HOME scan
if command -v whisper >/dev/null 2>&1; then
  WHISPER_EXEC="$(command -v whisper)"
else
  WHISPER_EXEC="$(find "$HOME" -type f -perm -u=x -name whisper 2>/dev/null | head -n1 || true)"
fi
[[ -n "$WHISPER_EXEC" ]] || { echo "Could not find 'whisper' executable in PATH or \$HOME" >&2; exit 1; }

# -------- Helpers --------
lower_ext() {
  local f="$1"
  local p="${f%%\?*}"                 # strip query
  p="${p%%\#*}"                        # strip fragment
  local e="${p##*.}"                   # extension
  printf '%s' "${e,,}"                 # lowercase
}

is_url() { [[ "$1" =~ ^https?:// ]]; }

output_flags_for() {
  case "$1" in
    txt)  echo "--output-txt" ;;
    vtt)  echo "--output-vtt" ;;
    srt)  echo "--output-srt" ;;
    json) echo "--output-json" ;;
    tsv)  echo "--output-csv" ;;    # whisper.cpp uses CSV/TSV-ish; adjust if your build differs
    lrc)  echo "--output-lrc" ;;
    all)  echo "--output-txt --output-vtt --output-srt --output-json --output-csv --output-lrc" ;;
    *)    echo "Invalid --output_format: $1. Use txt|vtt|srt|json|tsv|lrc|all" >&2; exit 1 ;;
  esac
}

# -------- Temp workspace & cleanup --------
WORKDIR="$(mktemp -d)"
trap 'rm -rf "$WORKDIR"' EXIT

SOURCE_PATH=""
MP3_PATH=""

# -------- Stage input (download if URL) --------
if is_url "$INPUT"; then
  ext="$(lower_ext "$INPUT")"
  case "$ext" in
    mp3|mp4) : ;;
    *) ext="mp3" ;;   # default if unknown
  esac
  SOURCE_PATH="$WORKDIR/input.$ext"
  echo "↓ Downloading: $INPUT"
  wget -q --show-progress -O "$SOURCE_PATH" "$INPUT"
else
  [[ -f "$INPUT" ]] || { echo "Error: file not found: $INPUT" >&2; exit 1; }
  SOURCE_PATH="$INPUT"
  ext="$(lower_ext "$SOURCE_PATH")"
fi

# -------- Transcode if needed --------
case "$ext" in
  mp3)
    MP3_PATH="$SOURCE_PATH"
    ;;
  mp4)
    MP3_PATH="$WORKDIR/audio.mp3"
    echo "🎞  Transcoding MP4 → MP3 with ffmpeg..."
    ffmpeg -y -i "$SOURCE_PATH" -vn -acodec libmp3lame -q:a 2 "$MP3_PATH" >/dev/null 2>&1
    ;;
  *)
    echo "Error: unsupported extension '$ext'. Only .mp3 or .mp4 are handled." >&2
    exit 1
    ;;
esac

# -------- Run whisper --------
OUT_FLAGS="$(output_flags_for "$OUTPUT_FORMAT")"
echo "▶ Running whisper"
echo "   model:    $MODEL"
echo "   language: $LANGUAGE"
echo "   outputs:  $OUTPUT_FORMAT"
echo "   input:    $MP3_PATH"
# shellcheck disable=SC2086
"$WHISPER_EXEC" "$MP3_PATH" --model "$MODEL" --device cuda --language "$LANGUAGE" $OUT_FLAGS