#!/bin/bash
# montage-mvt.sh — compile all daily clips for the current Vivaldi movement into
# a single montage that exactly matches the music duration, with 2-second
# audio/video fade in/out and a 7-second attribution card appended.
#
# Called automatically by 4-seasons.sh on the last day of each movement.
# Can also be run manually (e.g. to build a partial mid-season preview).
#
# Music: "The Four Seasons" by Antonio Vivaldi
# Performed by John Harrison with the Wichita State University Chamber Players
# Source: Free Music Archive — freemusicarchive.org
# License: CC BY-SA 3.0 — creativecommons.org/licenses/by-sa/3.0

set -euo pipefail

SCRIPT_DIR="$(dirname "$(realpath "$0")")"

# ── Configuration ──────────────────────────────────────────────────────────────
base_dir="/home/motion/drives/local-2tb"
music_base_dir="$base_dir/music/4 Seasons"
[ ! -d "$music_base_dir" ] && music_base_dir="$SCRIPT_DIR/music"

FADE_DUR=2.0   # seconds for video + audio fade in/out
ATTR_DUR=7     # duration of attribution card in seconds

# ── Season / movement info ────────────────────────────────────────────────────
# Optional first argument: YYYY-MM-DD of the last day of the movement to compile.
# Used when called automatically from 4-seasons.sh (which processes yesterday's
# images the next morning, so "today" would already be the next movement).
# When run manually with no argument, uses today — correct for same-day runs.
DATE_ARG="${1:-}"
eval "$(python3 "$SCRIPT_DIR/season_info.py" ${DATE_ARG:+"$DATE_ARG"})"
echo "Season=$SEASON  Mvt=$MVT_NUM  Day=$DAY_OF_MVT/$DAYS_IN_MVT  (ref date: ${DATE_ARG:-today})"

# ── Locate files ──────────────────────────────────────────────────────────────
script_name=$(basename "$SCRIPT_DIR" | cut -d'-' -f1)
video_dir="$base_dir/movies/$script_name/$SEASON/Mvt$MVT_NUM"
output_dir="$video_dir/montage"
mkdir -p "$output_dir"

music_file=$(find "$music_base_dir" -type f -iname "*${SEASON}*Mvt*${MVT_NUM}*" | sort | head -n 1)
if [ -z "$music_file" ]; then
    echo "ERROR: Music file not found for $SEASON Mvt $MVT_NUM"
    exit 1
fi
music_duration=$(ffprobe -v error -show_entries format=duration -of csv=p=0 "$music_file")
echo "Music: $(basename "$music_file")  ($music_duration s)"

# ── Collect sorted daily clips ─────────────────────────────────────────────────
mapfile -d '' daily_clips < <(find "$video_dir" -maxdepth 1 -name "*-final.mp4" -print0 | sort -z)
if [ "${#daily_clips[@]}" -eq 0 ]; then
    echo "ERROR: No *-final.mp4 clips in $video_dir"
    exit 1
fi
echo "Found ${#daily_clips[@]} daily clips"

# ── Detect source resolution from first clip ──────────────────────────────────
# The attribution card is created at this same resolution so nothing is resized.
VIDEO_W=$(ffprobe -v error -select_streams v:0 -show_entries stream=width  -of csv=p=0 "${daily_clips[0]}")
VIDEO_H=$(ffprobe -v error -select_streams v:0 -show_entries stream=height -of csv=p=0 "${daily_clips[0]}")
echo "Source resolution: ${VIDEO_W}x${VIDEO_H}"

# ── Temp-file tracking ────────────────────────────────────────────────────────
TMPFILES=()
cleanup() { rm -f "${TMPFILES[@]}" 2>/dev/null || true; }
trap cleanup EXIT

concat_list=$(mktemp --suffix=.txt); TMPFILES+=("$concat_list")
printf "file '%s'\n" "${daily_clips[@]}" > "$concat_list"

# ── Step 1: Concatenate clips, normalising to source resolution ───────────────
# Normalise in case any clip differs (e.g. camera settings changed on one day).
temp_concat=$(mktemp --suffix=.mp4); TMPFILES+=("$temp_concat")
echo "Step 1/5: concatenating ${#daily_clips[@]} clips..."
ffmpeg -loglevel warning \
    -f concat -safe 0 -i "$concat_list" \
    -vf "scale=${VIDEO_W}:${VIDEO_H}:force_original_aspect_ratio=decrease,\
pad=${VIDEO_W}:${VIDEO_H}:(ow-iw)/2:(oh-ih)/2,setsar=1" \
    -c:v libx264 -pix_fmt yuv420p -crf 26 -an \
    -y "$temp_concat"

# ── Step 2: Speed-adjust to match music duration exactly ──────────────────────
concat_dur=$(ffprobe -v error -show_entries format=duration -of csv=p=0 "$temp_concat")
speed_factor=$(echo "scale=6; $concat_dur / $music_duration" | bc)
echo "Step 2/5: speed factor $speed_factor  (raw=${concat_dur}s  music=${music_duration}s)"

temp_sped=$(mktemp --suffix=.mp4); TMPFILES+=("$temp_sped")
ffmpeg -loglevel warning \
    -i "$temp_concat" \
    -vf "setpts=PTS/$speed_factor" \
    -c:v libx264 -pix_fmt yuv420p -crf 26 -an \
    -t "$music_duration" -y "$temp_sped"
rm "$temp_concat"

# ── Step 3: Merge with music + 2-second video/audio fade in/out ───────────────
fade_out_start=$(echo "scale=3; $music_duration - $FADE_DUR" | bc)
echo "Step 3/5: adding music and fades..."

temp_main=$(mktemp --suffix=.mp4); TMPFILES+=("$temp_main")
ffmpeg -loglevel warning \
    -i "$temp_sped" -i "$music_file" \
    -filter_complex \
"[0:v]fade=t=in:st=0:d=${FADE_DUR},fade=t=out:st=${fade_out_start}:d=${FADE_DUR}[vout];\
[1:a]afade=t=in:st=0:d=${FADE_DUR},afade=t=out:st=${fade_out_start}:d=${FADE_DUR}[aout]" \
    -map "[vout]" -map "[aout]" \
    -c:v libx264 -pix_fmt yuv420p -c:a aac -b:a 192k \
    -t "$music_duration" -y "$temp_main"
rm "$temp_sped"

# ── Step 4: Create 7-second attribution card at source resolution ─────────────
# Resolution matches the video — no resizing of the main montage required.
echo "Step 4/5: creating attribution card at ${VIDEO_W}x${VIDEO_H}..."

FONT=""
FONT_BOLD=""
if command -v fc-match &>/dev/null; then
    FONT=$(fc-match "DejaVu Sans:style=Regular" --format="%{file}" 2>/dev/null || true)
    FONT_BOLD=$(fc-match "DejaVu Sans:style=Bold"    --format="%{file}" 2>/dev/null || true)
fi
if [ -z "$FONT" ]; then
    for f in \
        /usr/share/fonts/truetype/dejavu/DejaVuSans.ttf \
        /usr/share/fonts/dejavu/DejaVuSans.ttf \
        /usr/share/fonts/TTF/DejaVuSans.ttf \
        /usr/share/fonts/truetype/freefont/FreeSans.ttf; do
        [ -f "$f" ] && { FONT="$f"; break; }
    done
fi
[ -z "$FONT_BOLD" ] && FONT_BOLD="$FONT"

# Font sizes are proportional to frame height so they look right at any resolution.
# Colons inside drawtext text values must be escaped as \: (\\: in bash double-quotes).
DT="drawtext=fontfile='${FONT_BOLD}':text='The Four Seasons - Antonio Vivaldi':fontcolor=white:fontsize=h/19:x=(w-text_w)/2:y=h*0.15"
DT="${DT},drawtext=fontfile='${FONT}':text='Performed by John Harrison':fontcolor=0xDDDDDD:fontsize=h/26:x=(w-text_w)/2:y=h*0.32"
DT="${DT},drawtext=fontfile='${FONT}':text='with the Wichita State University Chamber Players':fontcolor=0xDDDDDD:fontsize=h/30:x=(w-text_w)/2:y=h*0.43"
DT="${DT},drawtext=fontfile='${FONT}':text='Source\\: Free Music Archive':fontcolor=white:fontsize=h/32:x=(w-text_w)/2:y=h*0.57"
DT="${DT},drawtext=fontfile='${FONT}':text='freemusicarchive.org':fontcolor=0xFFFF88:fontsize=h/32:x=(w-text_w)/2:y=h*0.66"
DT="${DT},drawtext=fontfile='${FONT}':text='License\\: CC BY-SA 3.0':fontcolor=0xCCCCCC:fontsize=h/34:x=(w-text_w)/2:y=h*0.76"
DT="${DT},fade=t=in:st=0:d=1,fade=t=out:st=$((ATTR_DUR-1)):d=1"

temp_attr=$(mktemp --suffix=.mp4); TMPFILES+=("$temp_attr")
ffmpeg -loglevel warning \
    -f lavfi -i "color=c=black:s=${VIDEO_W}x${VIDEO_H}:r=25:d=${ATTR_DUR}" \
    -f lavfi -i "anullsrc=r=44100:cl=stereo" \
    -vf "$DT" \
    -c:v libx264 -pix_fmt yuv420p -c:a aac -b:a 192k \
    -t "$ATTR_DUR" -y "$temp_attr"

# ── Step 5: Join montage + attribution card ───────────────────────────────────
echo "Step 5/5: joining montage and attribution card..."
final_list=$(mktemp --suffix=.txt); TMPFILES+=("$final_list")
printf "file '%s'\n" "$temp_main" "$temp_attr" > "$final_list"

output_file="$output_dir/$(date +%Y-%m-%d)_${SEASON}_Mvt${MVT_NUM}-Montage.mp4"
ffmpeg -loglevel warning \
    -f concat -safe 0 -i "$final_list" \
    -c copy -y "$output_file"

echo "Done: $output_file"