#!/bin/bash
# montage-mvt.sh — compile daily sunrise clips into a seasonal movement montage.
# Output: daily clips concatenated, speed-adjusted to match music duration,
# with 2-second video/audio fade in/out, followed by a 7-second attribution card.
#
# 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-NC-SA 4.0 — verify at the URL above before redistribution.

set -euo pipefail

# ── Configuration ──────────────────────────────────────────────────────────────
base_dir="/home/motion/drives/local-2tb"
script_name=$(basename "$(dirname "$(realpath "$0")")" | cut -d'-' -f1)
music_base_dir="$base_dir/music/4 Seasons"
# Fallback: use music/ directory next to this script (repo copy)
[ ! -d "$music_base_dir" ] && music_base_dir="$(dirname "$(realpath "$0")")/music"

TARGET_W=1280
TARGET_H=720
FADE_DUR=2.0
ATTR_DUR=7

# ── Season / movement detection ────────────────────────────────────────────────
day_of_year=$(date +%j | sed 's/^0*//')   # strip leading zeros for arithmetic

if   [ "$day_of_year" -ge 80  ] && [ "$day_of_year" -le 172 ]; then
    season="Spring"; season_start=80;  days_in_season=93
elif [ "$day_of_year" -ge 173 ] && [ "$day_of_year" -le 264 ]; then
    season="Summer"; season_start=173; days_in_season=92
elif [ "$day_of_year" -ge 265 ] && [ "$day_of_year" -le 355 ]; then
    season="Autumn"; season_start=265; days_in_season=91
else
    season="Winter"; days_in_season=90
    # Winter straddles the year boundary (day 356–79)
    if [ "$day_of_year" -ge 356 ]; then season_start=356; else season_start=0; fi
fi

# Day within the season (1-based)
if [ "$season" = "Winter" ] && [ "$day_of_year" -lt 80 ]; then
    day_of_season=$(( day_of_year + 365 - 355 ))
elif [ "$season" = "Winter" ]; then
    day_of_season=$(( day_of_year - 355 ))
else
    day_of_season=$(( day_of_year - season_start + 1 ))
fi

# Each season split into three movements of ~30 days each
if   [ "$day_of_season" -le 30 ]; then movement_num=1; days_in_movement=30
elif [ "$day_of_season" -le 60 ]; then movement_num=2; days_in_movement=30
else                                    movement_num=3; days_in_movement=$(( days_in_season - 60 ))
fi

echo "Season=$season  Mvt=$movement_num  DayOfSeason=$day_of_season  DaysInMvt=$days_in_movement"

# ── Locate input files ─────────────────────────────────────────────────────────
video_dir="$base_dir/movies/$script_name/$season/Mvt$movement_num"
output_dir="$video_dir/montage"
mkdir -p "$output_dir"

music_file=$(find "$music_base_dir" -type f -iname "*${season}*Mvt*${movement_num}*" | sort | head -n 1)
if [ -z "$music_file" ]; then
    echo "ERROR: Music file not found for $season Mvt $movement_num in $music_base_dir"
    exit 1
fi
music_duration=$(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 found in $video_dir"
    exit 1
fi
echo "Found ${#daily_clips[@]} daily clips"

# ── Temp-file tracking for cleanup ────────────────────────────────────────────
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 + normalise to TARGET_W x TARGET_H ────────────────────
temp_concat=$(mktemp --suffix=.mp4); TMPFILES+=("$temp_concat")
echo "Step 1/5: concatenating ${#daily_clips[@]} clips at ${TARGET_W}x${TARGET_H}..."
ffmpeg -loglevel warning \
    -f concat -safe 0 -i "$concat_list" \
    -vf "scale=${TARGET_W}:${TARGET_H}:force_original_aspect_ratio=decrease,\
pad=${TARGET_W}:${TARGET_H}:(ow-iw)/2:(oh-ih)/2,setsar=1" \
    -c:v libx264 -pix_fmt yuv420p -crf 26 -an -y "$temp_concat"

# ── Step 2: Speed-adjust so total video == music duration ─────────────────────
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  target=${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 + video/audio fades ──────────────────────────────
fade_out_start=$(echo "scale=3; $music_duration - $FADE_DUR" | bc)
echo "Step 3/5: merging music + fade in/out (fade=${FADE_DUR}s)..."

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 ──────────────────────────────────
echo "Step 4/5: building attribution card..."

# Locate a usable font
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"

# Build drawtext chain (colons in text values escaped as \: → \\: in bash string)
DT="drawtext=fontfile='${FONT_BOLD}':text='The Four Seasons - Antonio Vivaldi':fontcolor=white:fontsize=38:x=(w-text_w)/2:y=h*0.18"
DT="${DT},drawtext=fontfile='${FONT}':text='Performed by John Harrison':fontcolor=0xDDDDDD:fontsize=28:x=(w-text_w)/2:y=h*0.34"
DT="${DT},drawtext=fontfile='${FONT}':text='with the Wichita State University Chamber Players':fontcolor=0xDDDDDD:fontsize=22:x=(w-text_w)/2:y=h*0.44"
DT="${DT},drawtext=fontfile='${FONT}':text='Source\\: Free Music Archive':fontcolor=white:fontsize=21:x=(w-text_w)/2:y=h*0.59"
DT="${DT},drawtext=fontfile='${FONT}':text='freemusicarchive.org':fontcolor=0xFFFF88:fontsize=21:x=(w-text_w)/2:y=h*0.68"
DT="${DT},drawtext=fontfile='${FONT}':text='License\\: CC BY-NC-SA 4.0':fontcolor=0xCCCCCC:fontsize=19:x=(w-text_w)/2:y=h*0.78"
DT="${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=${TARGET_W}x${TARGET_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: Concatenate montage + attribution ─────────────────────────────────
echo "Step 5/5: appending attribution and writing final file..."
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)_${season}_Mvt${movement_num}-Montage.mp4"
ffmpeg -loglevel warning \
    -f concat -safe 0 -i "$final_list" \
    -c copy -y "$output_file"

echo "Done: $output_file"