#!/usr/bin/env ruby
# frozen_string_literal: true
#
# Usage: ruby organize_by_day.rb <album_dir> [--go]
#
# Groups media files in <album_dir> by EXIF date, reverse-geocodes the first
# GPS fix of each day, and moves files into "Day N - Location" subdirectories.
# Without --go it prints the plan only (dry run).

require 'json'
require 'date'
require 'net/http'
require 'uri'
require 'fileutils'

IMAGE_EXTS = %w[jpg jpeg png gif webp heic heif tiff bmp].freeze
VIDEO_EXTS = %w[mp4 mov avi mkv webm m4v ogv].freeze
MEDIA_EXTS = (IMAGE_EXTS + VIDEO_EXTS).freeze

album_dir = ARGV[0]
dry_run   = !ARGV.include?('--go')

# Clean up Nominatim names that are overly granular or wrong.
LOCATION_OVERRIDES = {
  /Jaipur Municipal Corporation/i => 'Jaipur',
  /Kothimahal Tahsil/i            => 'Ujjain',
}

abort "Usage: #{$PROGRAM_NAME} <album_dir> [--go]" unless album_dir
abort "Not a directory: #{album_dir}" unless File.directory?(album_dir)

def parse_exif_date(s)
  return nil unless s
  Date.parse(s.sub(/^(\d{4}):(\d{2}):(\d{2})/, '\1-\2-\3'))
rescue ArgumentError
  nil
end

def reverse_geocode(lat, lon)
  uri = URI("https://nominatim.openstreetmap.org/reverse?lat=#{lat}&lon=#{lon}&format=json&zoom=10")
  req = Net::HTTP::Get.new(uri)
  req['User-Agent'] = 'albumen-organizer/1.0 (self-hosted photo album)'
  res = Net::HTTP.start(uri.host, uri.port, use_ssl: true, open_timeout: 10, read_timeout: 10) do |h|
    h.request(req)
  end
  data = JSON.parse(res.body)
  addr = data['address'] || {}
  addr['city'] || addr['town'] || addr['village'] || addr['suburb'] ||
    addr['county'] || addr['state'] || 'Unknown'
rescue => e
  warn "  Geocode error: #{e.message}"
  'Unknown'
end

# ── Gather files ───────────────────────────────────────────────────────────────

files = Dir.children(album_dir)
           .select { |n| MEDIA_EXTS.include?(File.extname(n).downcase.delete_prefix('.')) }
           .sort

abort "No media files found in #{album_dir}" if files.empty?
puts "Found #{files.size} media files. Reading EXIF (batch)..."

# Run exiftool once over all files for speed
exif_out = `exiftool -json -DateTimeOriginal -CreateDate -GPSLatitude# -GPSLongitude# -norecurse "#{album_dir}" 2>/dev/null`
exif_map = JSON.parse(exif_out).each_with_object({}) do |e, h|
  h[File.basename(e['SourceFile'])] = e
end

file_info = files.map do |name|
  exif = exif_map[name] || {}
  raw  = exif['DateTimeOriginal'] || exif['CreateDate']
  {
    name: name,
    date: parse_exif_date(raw),
    lat:  exif['GPSLatitude'],
    lon:  exif['GPSLongitude'],
  }
end

# ── Group by date ──────────────────────────────────────────────────────────────

by_date   = file_info.group_by { |f| f[:date] }
no_date   = by_date.delete(nil) || []
puts "  #{no_date.size} files with no date (will be skipped)." if no_date.any?

sorted_dates = by_date.keys.sort
puts "#{sorted_dates.size} distinct days found."

# ── Build plan ─────────────────────────────────────────────────────────────────

plan = sorted_dates.each_with_index.map do |date, i|
  day_files = by_date[date].sort_by { |f| f[:name] }
  first_gps = day_files.find { |f| f[:lat] && f[:lon] }

  location = if first_gps
    print "  Geocoding Day #{i + 1} (#{date})... "
    STDOUT.flush
    loc = reverse_geocode(first_gps[:lat], first_gps[:lon])
    LOCATION_OVERRIDES.each { |pat, rep| loc = loc.gsub(pat, rep) }
    puts loc
    sleep 1.1  # Nominatim rate limit: 1 req/s
    loc
  else
    puts "  Day #{i + 1} (#{date}): no GPS, using 'Unknown'"
    'Unknown'
  end

  { date: date, dir: "Day #{i + 1} - #{location}", files: day_files.map { |f| f[:name] } }
end

# ── Print plan ─────────────────────────────────────────────────────────────────

puts "\n#{'=' * 60}"
puts dry_run ? 'DRY RUN — pass --go to execute' : 'EXECUTING'
puts '=' * 60
plan.each do |p|
  puts "#{p[:dir]}/  (#{p[:files].size} files)"
end
puts "#{no_date.size} files with no date left in place." if no_date.any?

exit if dry_run

# ── Execute ────────────────────────────────────────────────────────────────────

plan.each do |p|
  target = File.join(album_dir, p[:dir])
  FileUtils.mkdir_p(target)
  p[:files].each do |name|
    FileUtils.mv(File.join(album_dir, name), File.join(target, name))
  end
  puts "Created #{p[:dir]}/ (#{p[:files].size} files)"
end

puts "\nDone. Run update.rb to rebuild album.json files and thumbnails."