#!/usr/bin/env bash
set -euo pipefail
# POS: media yt-mp4 — Download video as MP4 (smart/interactive format select)
# POS_FLAGS: --format --best --worst --output --no-playlist --cookies --dry-run

source "$(dirname "$0")/../lib/common.sh" 2>/dev/null || source "$(dirname "$0")/common.sh"
source "$(dirname "$0")/../lib/yt-lib.sh" 2>/dev/null || source "$(dirname "$0")/yt-lib.sh"

# --dry-run is parsed before the deps guards (below): it previews the yt-dlp
# command without requiring yt-dlp/ffmpeg to be installed.
DRY_RUN=0
for arg in "$@"; do
    [ "$arg" = "--dry-run" ] && DRY_RUN=1
done

# Deps guards sit before -h|--help (help also errors on a box missing the deps).
# yt_check_deps with dry-run=1 skips the dep checks (dry-run preview needs none).
yt_check_deps "$DRY_RUN" "MP4 merge"

# Env seam: YT_OUT_DIR overrides the default (keeps HOME sandbox-compatible).
OUT_DIR="${YT_OUT_DIR:-$HOME/Videos}"
FORMAT=""
BEST=0
WORST=0
EXTRA_ARGS=()

usage() {
    cat <<EOF
Usage: pos media yt mp4 [options] <url>

Download video from a URL via yt-dlp. Without -f/--best/--worst, formats are
listed and picked interactively.

Options:
  -f, --format <id>     Download that format id directly (no prompt)
  --best                Best video + audio (no prompt)
  --worst               Lowest quality (no prompt)
  -o, --output <dir>    Output directory (default: $OUT_DIR)
  --no-playlist         Download only the single video
  --cookies <file>      Netscape cookies.txt for age-gated content
  --dry-run             Print the yt-dlp command without running it
  -h, --help            This help

Examples:
  pos media yt mp4 https://youtube.com/watch?v=dQw4w9WgXcQ
  pos media yt mp4 --best https://youtube.com/watch?v=dQw4w9WgXcQ
  pos media yt mp4 -f 22 https://youtube.com/watch?v=dQw4w9WgXcQ
EOF
    exit 0
}

URL=""
while [[ $# -gt 0 ]]; do
    case "$1" in
        -h|--help) usage ;;
        -f|--format)
            [ $# -ge 2 ] || err "--format needs a value"
            FORMAT="$2"; shift 2 ;;
        --best) BEST=1; shift ;;
        --worst) WORST=1; shift ;;
        -o|--output)
            [ $# -ge 2 ] || err "--output needs a value"
            OUT_DIR="$2"; shift 2 ;;
        --no-playlist) EXTRA_ARGS+=(--no-playlist); shift ;;
        --cookies)
            [ $# -ge 2 ] || err "--cookies needs a value"
            [ -f "$2" ] || err "cookies file not found: $2"
            EXTRA_ARGS+=(--cookies "$2"); shift 2 ;;
        --dry-run) DRY_RUN=1; shift ;;
        -*) err "Unknown option: $1 (see --help)" ;;
        *)
            [ -z "$URL" ] && URL="$1" && shift || err "Unexpected argument: $1" ;;
    esac
done
[ -n "$URL" ] || usage

[ -n "$FORMAT" ] && { [ "$BEST" -eq 1 ] || [ "$WORST" -eq 1 ]; } \
    && err "--format and --best/--worst are mutually exclusive"
[ "$BEST" -eq 1 ] && [ "$WORST" -eq 1 ] && err "--best and --worst are mutually exclusive"

# Resolve the format selector: explicit flag → smart preset → interactive.
# The curated table goes to stderr; stdout carries ONLY the chosen format id
# (same ui_pick lesson — a $(...) capture must not swallow the menu).
fmt_spec=""
if [ -n "$FORMAT" ]; then
    fmt_spec="$FORMAT"
elif [ "$BEST" -eq 1 ]; then
    fmt_spec="bestvideo*+bestaudio/best"
elif [ "$WORST" -eq 1 ]; then
    fmt_spec="worst"
else
    table="$(yt-dlp -F "$URL" 2>&1)" || {
        echo "ERROR: no formats listed (unsupported site or age-gated content)" >&2
        exit 1
    }
    printf '%s' "$table" | awk -F'[[:space:]][[:space:]]+' '
        NR <= 2 { print; next }
        $0 ~ /^-+$/ { print; next }
        $0 ~ /audio only/ && $0 !~ /storyboard/ && $1 !~ /^sb/ { print "  [audio] " $0; next }
        $0 ~ /video only/ && $1 !~ /^sb/ { print "  [video] " $0; next }
        $1 ~ /^[0-9]+$/ && $2 ~ /^(mp4|webm)$/ && $3 ~ /x/ { print "  [combo] " $0 }
    ' >&2
    echo >&2
    read -rp "Format ID ('best'/'worst'/empty = best): " chosen
    case "${chosen:-best}" in
        best) fmt_spec="bestvideo*+bestaudio/best" ;;
        worst) fmt_spec="worst" ;;
        *)
            if printf '%s' "$table" | grep -qE "^[[:space:]]*${chosen}[[:space:]]"; then
                fmt_spec="$chosen"
            else
                echo "ERROR: unknown format id '$chosen'" >&2
                exit 1
            fi
            ;;
    esac
fi

args=(yt-dlp -f "$fmt_spec"
    --merge-output-format mp4
    --embed-metadata --embed-chapters
    --embed-subs --sub-langs all
    --embed-thumbnail
    --no-overwrites
    -o "$OUT_DIR/%(title)s.%(ext)s"
    "${EXTRA_ARGS[@]}" "$URL")

if [ "$DRY_RUN" -eq 1 ]; then
    echo "yt-dlp ${args[*]:1}"
else
    spawn "downloading video → $OUT_DIR" "${args[@]}"
fi