#!/bin/bash
# daily_sunrise_video.sh — collect today's sunrise images, speed-adjust to
# SUNRISE_TARGET_SECS, burn the local sunrise time vertically on the right
# side, and write the final video.  Upload is handled by a separate systemd
# service (sky-cam-sunrise-upload) triggered via OnSuccess= so the two jobs
# have independent log entries and failure states.

set -euo pipefail

SCRIPT_DIR="$(dirname "$(realpath "$0")")"
source "$SCRIPT_DIR/sky-cam.conf"
export TZ="$TIMEZONE"

# ── Date / paths ──────────────────────────────────────────────────────────────
current_date=$(date +%Y-%m-%d)
output_date=$(date +%Y-%m)

image_dir="$BASE_DIR/$CAM_NAME/$current_date"
output_dir="$BASE_DIR/movies/$CAM_NAME/$output_date/sunrise-only"
mkdir -p "$output_dir"

# ── Sunrise time ──────────────────────────────────────────────────────────────
sunrise_time=$(python3 "$SCRIPT_DIR/sunrise.py")
if [[ -z "$sunrise_time" ]]; then
    echo "Error: Failed to retrieve sunrise time."
    exit 1
fi
echo "Sunrise (UTC): $sunrise_time"

sunrise_time_local=$(TZ="$TIMEZONE" date -d "$sunrise_time" +"%H-%M-%S")
echo "Sunrise (local): $sunrise_time_local"

# ── Capture window ────────────────────────────────────────────────────────────
time_to_seconds() { IFS='-' read -r h m s <<< "$1"; echo $((10#$h * 3600 + 10#$m * 60 + 10#$s)); }

sunrise_sec=$(time_to_seconds "$sunrise_time_local")
start_sec=$((sunrise_sec - SUNRISE_PRE_MIN * 60))
end_sec=$((sunrise_sec + SUNRISE_POST_MIN * 60))
echo "Window: $((start_sec/3600)):$(printf '%02d' $(((start_sec%3600)/60))) → $((end_sec/3600)):$(printf '%02d' $(((end_sec%3600)/60)))"

# ── Collect images in window ──────────────────────────────────────────────────
if [ ! -d "$image_dir" ]; then
    echo "Error: image directory not found: $image_dir"
    exit 1
fi

temp_list=$(mktemp --suffix=.txt)
trap 'rm -f "$temp_list" "$raw_video" 2>/dev/null || true' EXIT

find "$image_dir" -type f -name "*.jpg" | sort | while read -r img; do
    img_sec=$(time_to_seconds "$(basename "$img" .jpg)")
    if [[ $img_sec -ge $start_sec && $img_sec -le $end_sec ]]; then
        echo "file '$img'"
    fi
done > "$temp_list"

num_images=$(wc -l < "$temp_list")
if [[ $num_images -lt 1 ]]; then
    echo "No images found in sunrise window."
    exit 1
fi
echo "Images in window: $num_images"

# ── Font detection (same fallback chain as montage-mvt.sh) ───────────────────
FONT=""
if command -v fc-match &>/dev/null; then
    FONT=$(fc-match "DejaVu Sans:style=Regular" --format="%{file}" 2>/dev/null || true)
fi
if [ -z "$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

# ── Step 1: Raw video from images ─────────────────────────────────────────────
raw_video=$(mktemp --suffix=.mp4)
echo "Step 1/2: encoding raw video..."
ffmpeg -loglevel warning \
    -f concat -safe 0 -i "$temp_list" \
    -c:v libx264 -pix_fmt yuv420p -crf "$CRF_SUNRISE" -vsync 2 -an \
    -y "$raw_video"

raw_dur=$(ffprobe -v error -show_entries format=duration -of csv=p=0 "$raw_video")
speed_factor=$(echo "scale=3; $raw_dur / $SUNRISE_TARGET_SECS" | bc)
echo "Raw: ${raw_dur}s  speed factor: ${speed_factor}x"

# ── Step 2: Speed-adjust + sunrise time overlay ───────────────────────────────
# Time displayed as stacked characters down the right side (e.g. 0/7/:/2/3),
# semi-transparent with a soft drop shadow so it reads on any background.
SR_TIME=$(echo "$sunrise_time_local" | cut -d'-' -f1,2 | tr '-' ':')
# Build "H\nH\n:\nM\nM" for vertical stacking in drawtext
SR_VERT=$(echo "$SR_TIME" | awk 'BEGIN{FS=""}{for(i=1;i<=NF;i++){printf "%s",$i; if(i<NF)printf "\\n"}}')

DT="drawtext"
[ -n "$FONT" ] && DT="${DT}=fontfile='${FONT}'" || DT="${DT}"
DT="${DT}:text='${SR_VERT}'"
DT="${DT}:fontcolor=white@${SUNRISE_OVERLAY_OPACITY}"
DT="${DT}:fontsize=h/22"
DT="${DT}:line_spacing=4"
DT="${DT}:x=w-tw-18:y=(h-th)/2"
DT="${DT}:shadowcolor=black@0.55:shadowx=1:shadowy=1"

final_video="$output_dir/$current_date-daily-sunrise.mp4"
echo "Step 2/2: speed-adjust + overlay → $final_video"

ffmpeg -loglevel warning \
    -i "$raw_video" \
    -vf "setpts=PTS/${speed_factor},${DT}" \
    -c:v libx264 -pix_fmt yuv420p -crf "$CRF_SUNRISE" -an \
    -y "$final_video"

actual_dur=$(ffprobe -v error -show_entries format=duration -of csv=p=0 "$final_video")
echo "Done: $final_video  (${actual_dur}s, sunrise at ${SR_TIME})"