#!/bin/bash
# reorg-backup.sh — reorganize backup season files into astro-YEAR folders.
#
# Moves files from:
#   <backup_root>/<cam>/Season/MvtN/YYYY-MM-DD_*
# Into:
#   <backup_root>/astro-YEAR/<cam>/Season/MvtN/YYYY-MM-DD_*
#
# Uses season_info.py to determine the correct ASTRO_YEAR from each file's date.
# NEVER deletes anything — only moves files.
#
# Usage:
#   ./reorg-backup.sh <backup_root> [--dry-run]
#
# Example:
#   ./reorg-backup.sh ~/drives/data2-main --dry-run
#   ./reorg-backup.sh ~/drives/data2-main

set -euo pipefail

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

BACKUP_ROOT=""
DRY_RUN=false

while [[ $# -gt 0 ]]; do
    case "$1" in
        --dry-run) DRY_RUN=true; shift ;;
        -*)        echo "Unknown option: $1"; exit 1 ;;
        *)         BACKUP_ROOT="$1"; shift ;;
    esac
done

if [ -z "$BACKUP_ROOT" ]; then
    echo "Usage: $0 <backup_root> [--dry-run]"
    echo "  e.g. $0 ~/drives/data2-main --dry-run"
    exit 1
fi

BACKUP_ROOT="$(realpath "$BACKUP_ROOT")"

$DRY_RUN && echo "DRY RUN — no files will be moved"
echo "Backup root: $BACKUP_ROOT"
echo ""

moved=0
skipped=0
errors=0

# Find all mp4 files in Season/MvtN directories (not already in astro-* dirs)
while IFS= read -r -d '' src_file; do
    filename="$(basename "$src_file")"

    # Extract date: handles YYYY-MM-DD_ (underscore) prefix
    date_str="${filename%%_*}"
    if ! [[ "$date_str" =~ ^[0-9]{4}-[0-9]{2}-[0-9]{2}$ ]]; then
        echo "SKIP (unrecognised filename): $src_file"
        (( skipped++ )) || true
        continue
    fi

    # Get ASTRO_YEAR for this date
    _info="$(python3 "$SCRIPT_DIR/season_info.py" "$date_str" 2>/dev/null)" || {
        echo "SKIP (season_info.py failed for $date_str): $filename"
        (( skipped++ )) || true
        continue
    }
    eval "$_info"

    # Reconstruct target path:
    #   <backup_root>/astro-YEAR/<cam>/<Season>/Mvt<N>/<filename>
    # Source path is:
    #   <backup_root>/<cam>/<Season>/Mvt<N>/<filename>
    rel_path="${src_file#$BACKUP_ROOT/}"          # e.g. north/Winter/Mvt1/2025-01-06_...
    cam_and_below="${rel_path#*/}"                # e.g. Winter/Mvt1/2025-01-06_...  (strip cam)
    cam_name="${rel_path%%/*}"                    # e.g. north

    dest_dir="$BACKUP_ROOT/astro-${ASTRO_YEAR}/$cam_name/$(dirname "$cam_and_below")"
    dest_file="$dest_dir/$filename"

    if [ "$src_file" = "$dest_file" ]; then
        (( skipped++ )) || true
        continue
    fi

    if [ -f "$dest_file" ]; then
        echo "EXISTS — skip: astro-${ASTRO_YEAR}/$cam_name/$cam_and_below"
        (( skipped++ )) || true
        continue
    fi

    echo "MOVE  astro-${ASTRO_YEAR}/$cam_name/$cam_and_below"

    if ! $DRY_RUN; then
        mkdir -p "$dest_dir"
        if mv "$src_file" "$dest_file"; then
            (( moved++ )) || true
        else
            echo "  ERROR: mv failed"
            (( errors++ )) || true
        fi
    else
        (( moved++ )) || true
    fi

done < <(find "$BACKUP_ROOT" \
    -not -path "*/astro-*" \
    -regextype posix-extended \
    -regex ".*/[A-Z][a-z]+/Mvt[0-9]+/[0-9]{4}-[0-9]{2}-[0-9]{2}_.*\.mp4" \
    -print0 | sort -z)

echo ""
echo "────────────────────────────────────────"
echo "Moved: $moved   Skipped: $skipped   Errors: $errors"
$DRY_RUN && echo "(dry run — re-run without --dry-run to move files)"