# frozen_string_literal: true

require "date"

module Reconciliation
  class DolibarrFetcher
    # Dolibarr invoice statuses
    STATUS_DRAFT     = 0
    STATUS_VALIDATED = 1
    STATUS_PAID      = 2
    STATUS_CANCELLED = 3

    Invoice = Struct.new(
      :id,          # Dolibarr internal ID
      :ref,         # Invoice reference, e.g. "FA2407-0003"
      :status,      # 0=draft, 1=validated/open, 2=paid, 3=cancelled
      :total_ttc,   # Total amount TTC (euros, float)
      :amount_cents, # total_ttc * 100, rounded (integer)
      :paye,        # 0=unpaid, 1=paid
      :sumpayed,    # Amount already paid (euros)
      :remain_to_pay, # Remaining balance (euros)
      :date,        # Invoice date (Date)
      :due_date,    # Due date (Date)
      :customer_id, # socid
      :customer_name, # nom of third party if present
      :is_credit_note, # true if this is a credit note (negative amount)
      keyword_init: true
    )

    def initialize(client, from:, to:)
      @client = client
      @from   = from
      @to     = to
    end

    # Fetches all validated invoices and resolves customer names.
    # Note: querying status=1 returns all non-draft invoices in Dolibarr (open, paid, cancelled).
    # Cancelled invoices are filtered out here.
    def fetch_invoices
      $stderr.puts "[DolibarrFetcher] Fetching thirdparty names..."
      name_by_id = fetch_thirdparty_names

      $stderr.puts "[DolibarrFetcher] Fetching invoices..."
      raw_invoices = fetch_all(status: STATUS_VALIDATED)

      invoices = raw_invoices
        .map { |raw| parse_invoice(raw, name_by_id) }
        .reject { |inv| inv.status == STATUS_CANCELLED }
        .reject { |inv| inv.is_credit_note } # Credit notes (negative amounts) excluded from GC reconciliation

      open_count = invoices.count { |inv| inv.status == STATUS_VALIDATED }
      paid_count = invoices.count { |inv| inv.status == STATUS_PAID }
      $stderr.puts "[DolibarrFetcher] Total: #{invoices.size} invoices (#{open_count} open, #{paid_count} paid)"
      invoices
    rescue Dolibarr::Client::Error => e
      $stderr.puts "[DolibarrFetcher] Error: #{e.message}"
      raise
    end

    private

    def fetch_all(status:, sqlfilters: nil)
      invoices = []
      page = 0
      loop do
        params = { status: status, limit: 100, page: page }
        params[:sqlfilters] = sqlfilters if sqlfilters
        batch = @client.get("/invoices", params)
        break if batch.nil? || !batch.is_a?(Array) || batch.empty?

        invoices.concat(batch)
        break if batch.size < 100

        page += 1
      end
      invoices
    end

    def parse_invoice(raw, name_by_id = {})
      customer_id = raw["socid"].to_i
      total_ttc = raw["total_ttc"].to_f
      Invoice.new(
        id:             raw["id"].to_i,
        ref:            raw["ref"].to_s.strip,
        status:         raw["statut"].to_i,
        total_ttc:      total_ttc,
        amount_cents:   (total_ttc * 100).round,
        paye:           raw["paye"].to_i,
        sumpayed:       raw["sumpayed"].to_f,
        remain_to_pay:  raw["remaintopay"].to_f,
        date:           parse_unix_date(raw["datef"] || raw["date"]),
        due_date:       parse_unix_date(raw["date_lim_reglement"]),
        customer_id:    customer_id,
        customer_name:  name_by_id[customer_id] || raw.dig("thirdparty", "name").to_s.strip,
        is_credit_note: total_ttc < 0
      )
    end

    def fetch_thirdparty_names
      result = {}
      page = 0
      loop do
        batch = @client.get("/thirdparties", limit: 100, page: page)
        break if batch.nil? || !batch.is_a?(Array) || batch.empty?
        batch.each { |tp| result[tp["id"].to_i] = tp["name"].to_s.strip }
        break if batch.size < 100
        page += 1
      end
      result
    end

    def parse_unix_date(value)
      return nil if value.nil? || value.to_s.strip.empty? || value.to_i.zero?
      Time.at(value.to_i).utc.to_date
    rescue
      nil
    end
  end
end