#!/bin/bash
# migrate-seasons.sh — map old-format seasons clips to the new sky-cam directory
# structure using season_info.py to correctly categorize each clip by date.
#
# The old system used different movement-boundary and naming conventions;
# this script ignores the old labels and re-classifies every clip by its
# YYYY-MM-DD filename prefix, placing it exactly where montage-mvt.sh expects.
#
# Usage:
#   ./migrate-seasons.sh [--dry-run] [OLD_ROOT]
#
#   --dry-run   print what would happen without creating any links
#   OLD_ROOT    root of old movie archive (default: ~/drives/local-2tb/movies/sunrise)
#
# Output: symlinks in $MOVIES_DIR/<cam>/<ASTRO_YEAR>/<SEASON>/Mvt<N>/
#
# After running, trigger any completed movement montages manually:
#   ./montage-mvt.sh 2026-04-19 east   # Spring Mvt1 (just completed)
#   ./montage-mvt.sh 2026-01-18 east   # Winter Mvt1
#   ./montage-mvt.sh 2026-02-16 east   # Winter Mvt2
#   ./montage-mvt.sh 2026-03-19 east   # Winter Mvt3

set -euo pipefail

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

DRY_RUN=false
OLD_ROOT="$HOME/drives/local-2tb/movies/sunrise"

for arg in "$@"; do
    case "$arg" in
        --dry-run) DRY_RUN=true ;;
        *)         OLD_ROOT="$arg" ;;
    esac
done

CAM="$SUNRISE_CAM"
NEW_ROOT="$MOVIES_DIR/$CAM"

echo "Old archive : $OLD_ROOT"
echo "New root    : $NEW_ROOT"
echo "Camera      : $CAM"
$DRY_RUN && echo "(DRY RUN — no files will be created)"
echo ""

# Counters per movement
declare -A LINKED SKIPPED ERRORS

link_clip() {
    local src="$1" dst_dir="$2" key="$3"
    local dst="$dst_dir/$(basename "$src")"
    if [ -e "$dst" ]; then
        SKIPPED["$key"]=$(( ${SKIPPED["$key"]:-0} + 1 ))
        return
    fi
    if $DRY_RUN; then
        echo "  LINK $(basename "$src")"
        echo "    -> $dst"
    else
        mkdir -p "$dst_dir"
        ln -sf "$src" "$dst"
    fi
    LINKED["$key"]=$(( ${LINKED["$key"]:-0} + 1 ))
}

# Search the season subdirectories for old *-final.mp4 clips
while IFS= read -r -d '' src; do
    fname="$(basename "$src")"

    # Extract YYYY-MM-DD from filename prefix
    date_str="${fname%%_*}"
    if [[ ! "$date_str" =~ ^[0-9]{4}-[0-9]{2}-[0-9]{2}$ ]]; then
        echo "SKIP (no date): $fname"
        continue
    fi

    # Classify by date using the new system's season_info.py
    if ! info="$(python3 "$SCRIPT_DIR/season_info.py" "$date_str" 2>/dev/null)"; then
        echo "ERROR: season_info.py failed for $date_str ($fname)"
        continue
    fi
    eval "$info"
    # SEASON  MVT_NUM  DAY_OF_MVT  DAYS_IN_MVT  MVT_START  MVT_END  ASTRO_YEAR

    dst_dir="$NEW_ROOT/$ASTRO_YEAR/$SEASON/Mvt$MVT_NUM"
    key="${ASTRO_YEAR}/${SEASON}/Mvt${MVT_NUM}"

    $DRY_RUN && printf "  %-12s  %s Mvt%s  Day %s/%s\n" \
        "$date_str" "$SEASON" "$MVT_NUM" "$DAY_OF_MVT" "$DAYS_IN_MVT"

    link_clip "$src" "$dst_dir" "$key"

done < <(find \
    "$OLD_ROOT/Spring" \
    "$OLD_ROOT/Winter" \
    "$OLD_ROOT/Autumn" \
    -name "*-final.mp4" -print0 2>/dev/null | sort -z)

echo ""
echo "=== Summary ==="
printf "%-35s  %8s  %8s\n" "Movement" "Linked" "Skipped"
printf "%-35s  %8s  %8s\n" "--------" "------" "-------"

# Collect all movement keys from both arrays
declare -A ALL_KEYS
for k in "${!LINKED[@]}" "${!SKIPPED[@]}"; do ALL_KEYS["$k"]=1; done

for key in $(printf '%s\n' "${!ALL_KEYS[@]}" | sort); do
    linked=${LINKED["$key"]:-0}
    skipped=${SKIPPED["$key"]:-0}
    printf "%-35s  %8d  %8d\n" "$key" "$linked" "$skipped"
done

echo ""
if $DRY_RUN; then
    echo "Re-run without --dry-run to create the symlinks."
    echo "Then trigger montages for completed movements:"
else
    echo "Symlinks created.  Trigger montages for completed movements:"
fi
echo "  ./montage-mvt.sh 2026-04-19 $CAM   # Spring Mvt1 (just completed, 30/31 days)"
echo "  ./montage-mvt.sh 2026-01-18 $CAM   # Winter Mvt1 (~18/29 days)"
echo "  ./montage-mvt.sh 2026-02-16 $CAM   # Winter Mvt2 (~24/29 days)"
echo "  ./montage-mvt.sh 2026-03-19 $CAM   # Winter Mvt3 (~20/31 days)"
echo "  # Autumn Mvt1/Mvt3 migrated but Mvt2 is absent — year-end join will not fire."