/*
 * Copyright 2010-2011 Ning, Inc.
 *
 * Ning licenses this file to you under the Apache License, version 2.0
 * (the "License"); you may not use this file except in compliance with the
 * License.  You may obtain a copy of the License at:
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
 * License for the specific language governing permissions and limitations
 * under the License.
 */

package com.ning.billing.invoice.api.user;

import java.io.IOException;
import java.math.BigDecimal;
import java.util.List;
import java.util.Map;
import java.util.UUID;

import javax.annotation.Nullable;

import org.joda.time.DateTime;
import org.joda.time.LocalDate;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.ning.billing.ErrorCode;
import com.ning.billing.ObjectType;
import com.ning.billing.account.api.Account;
import com.ning.billing.account.api.AccountApiException;
import com.ning.billing.catalog.api.Currency;
import com.ning.billing.invoice.InvoiceDispatcher;
import com.ning.billing.invoice.api.Invoice;
import com.ning.billing.invoice.api.InvoiceApiException;
import com.ning.billing.invoice.api.InvoiceItem;
import com.ning.billing.invoice.api.InvoicePayment;
import com.ning.billing.invoice.api.InvoiceUserApi;
import com.ning.billing.invoice.dao.InvoiceDao;
import com.ning.billing.invoice.model.CreditAdjInvoiceItem;
import com.ning.billing.invoice.model.ExternalChargeInvoiceItem;
import com.ning.billing.invoice.template.HtmlInvoiceGenerator;
import com.ning.billing.util.api.TagApiException;
import com.ning.billing.util.callcontext.CallContext;
import com.ning.billing.util.callcontext.InternalCallContext;
import com.ning.billing.util.callcontext.InternalCallContextFactory;
import com.ning.billing.util.callcontext.InternalTenantContext;
import com.ning.billing.util.callcontext.TenantContext;
import com.ning.billing.util.svcapi.account.AccountInternalApi;
import com.ning.billing.util.svcapi.tag.TagInternalApi;
import com.ning.billing.util.svcsapi.bus.InternalBus;
import com.ning.billing.util.svcsapi.bus.InternalBus.EventBusException;
import com.ning.billing.util.tag.ControlTagType;
import com.ning.billing.util.tag.Tag;

import com.google.inject.Inject;

public class DefaultInvoiceUserApi implements InvoiceUserApi {

    private static final Logger log = LoggerFactory.getLogger(DefaultInvoiceUserApi.class);

    private final InvoiceDao dao;
    private final InvoiceDispatcher dispatcher;
    private final AccountInternalApi accountUserApi;
    private final TagInternalApi tagApi;
    private final HtmlInvoiceGenerator generator;
    private final InternalCallContextFactory internalCallContextFactory;
    private final InternalBus eventBus;

    @Inject
    public DefaultInvoiceUserApi(final InvoiceDao dao, final InvoiceDispatcher dispatcher, final AccountInternalApi accountUserApi, final InternalBus eventBus,
                                 final TagInternalApi tagApi, final HtmlInvoiceGenerator generator, final InternalCallContextFactory internalCallContextFactory) {
        this.dao = dao;
        this.dispatcher = dispatcher;
        this.accountUserApi = accountUserApi;
        this.tagApi = tagApi;
        this.generator = generator;
        this.internalCallContextFactory = internalCallContextFactory;
        this.eventBus = eventBus;
    }

    @Override
    public List<Invoice> getInvoicesByAccount(final UUID accountId, final TenantContext context) {
        return dao.getInvoicesByAccount(accountId, internalCallContextFactory.createInternalTenantContext(context));
    }

    @Override
    public List<Invoice> getInvoicesByAccount(final UUID accountId, final LocalDate fromDate, final TenantContext context) {
        return dao.getInvoicesByAccount(accountId, fromDate, internalCallContextFactory.createInternalTenantContext(context));
    }

    @Override
    public BigDecimal getAccountBalance(final UUID accountId, final TenantContext context) {
        final BigDecimal result = dao.getAccountBalance(accountId, internalCallContextFactory.createInternalTenantContext(context));
        return result == null ? BigDecimal.ZERO : result;
    }

    @Override
    public BigDecimal getAccountCBA(final UUID accountId, final TenantContext context) {
        final BigDecimal result = dao.getAccountCBA(accountId, internalCallContextFactory.createInternalTenantContext(context));
        return result == null ? BigDecimal.ZERO : result;
    }

    @Override
    public Invoice getInvoice(final UUID invoiceId, final TenantContext context) throws InvoiceApiException {
        return dao.getById(invoiceId, internalCallContextFactory.createInternalTenantContext(context));
    }

    @Override
    public Invoice getInvoiceByNumber(final Integer number, final TenantContext context) throws InvoiceApiException {
        return dao.getByNumber(number, internalCallContextFactory.createInternalTenantContext(context));
    }

    @Override
    public List<Invoice> getUnpaidInvoicesByAccountId(final UUID accountId, final LocalDate upToDate, final TenantContext context) {
        return dao.getUnpaidInvoicesByAccountId(accountId, upToDate, internalCallContextFactory.createInternalTenantContext(context));
    }

    @Override
    public Invoice triggerInvoiceGeneration(final UUID accountId, final LocalDate targetDate, final boolean dryRun,
                                            final CallContext context) throws InvoiceApiException {

        final Account account;
        try {
            account = accountUserApi.getAccountById(accountId, internalCallContextFactory.createInternalTenantContext(context));
        } catch (AccountApiException e) {
            throw new InvoiceApiException(e, ErrorCode.ACCOUNT_DOES_NOT_EXIST_FOR_ID, e.toString());
        }

        // API_FIX Could we avoid the first call to createInternalTenantContext
        final InternalCallContext internalContext = internalCallContextFactory.createInternalCallContext(accountId, context);
        final DateTime processingDateTime = targetDate.toDateTimeAtCurrentTime(account.getTimeZone());
        final Invoice result = dispatcher.processAccount(accountId, processingDateTime, dryRun, internalContext);
        if (result == null) {
            throw new InvoiceApiException(ErrorCode.INVOICE_NOTHING_TO_DO, accountId, targetDate);
        } else {
            return result;
        }
    }

    @Override
    public void tagInvoiceAsWrittenOff(final UUID invoiceId, final CallContext context) throws TagApiException, InvoiceApiException {
        // Note: the tagApi is audited
        final InternalCallContext internalContext = internalCallContextFactory.createInternalCallContext(context);
        tagApi.addTag(invoiceId, ObjectType.INVOICE, ControlTagType.WRITTEN_OFF.getId(), internalContext);

        // Retrieve the invoice for the account id
        final Invoice invoice = dao.getById(invoiceId, internalContext);
        // This is for overdue
        notifyBusOfInvoiceAdjustment(invoiceId, invoice.getAccountId(), context.getUserToken(), internalCallContextFactory.createInternalCallContext(invoice.getAccountId(), context));
    }

    @Override
    public void tagInvoiceAsNotWrittenOff(final UUID invoiceId, final CallContext context) throws TagApiException, InvoiceApiException {
        // Note: the tagApi is audited
        final InternalCallContext internalContext = internalCallContextFactory.createInternalCallContext(context);
        tagApi.removeTag(invoiceId, ObjectType.INVOICE, ControlTagType.WRITTEN_OFF.getId(), internalContext);

        // Retrieve the invoice for the account id
        final Invoice invoice = dao.getById(invoiceId, internalContext);
        // This is for overdue
        notifyBusOfInvoiceAdjustment(invoiceId, invoice.getAccountId(), context.getUserToken(), internalCallContextFactory.createInternalCallContext(invoice.getAccountId(), context));
    }

    @Override
    public InvoiceItem getExternalChargeById(final UUID externalChargeId, final TenantContext context) throws InvoiceApiException {
        final InvoiceItem externalChargeItem = dao.getExternalChargeById(externalChargeId, internalCallContextFactory.createInternalTenantContext(context));
        if (externalChargeItem == null) {
            throw new InvoiceApiException(ErrorCode.INVOICE_NO_SUCH_EXTERNAL_CHARGE, externalChargeId);
        }

        return new ExternalChargeInvoiceItem(externalChargeItem.getId(), externalChargeItem.getInvoiceId(), externalChargeItem.getAccountId(),
                                             externalChargeItem.getPlanName(), externalChargeItem.getStartDate(),
                                             externalChargeItem.getAmount(), externalChargeItem.getCurrency());
    }

    @Override
    public InvoiceItem insertExternalCharge(final UUID accountId, final BigDecimal amount, @Nullable final String description,
                                            final LocalDate effectiveDate, final Currency currency, final CallContext context) throws InvoiceApiException {
        return insertExternalChargeForInvoiceAndBundle(accountId, null, null, amount, description, effectiveDate, currency, context);
    }

    @Override
    public InvoiceItem insertExternalChargeForBundle(final UUID accountId, final UUID bundleId, final BigDecimal amount, @Nullable final String description,
                                                     final LocalDate effectiveDate, final Currency currency, final CallContext context) throws InvoiceApiException {
        return insertExternalChargeForInvoiceAndBundle(accountId, null, bundleId, amount, description, effectiveDate, currency, context);
    }

    @Override
    public InvoiceItem insertExternalChargeForInvoice(final UUID accountId, final UUID invoiceId, final BigDecimal amount, @Nullable final String description,
                                                      final LocalDate effectiveDate, final Currency currency, final CallContext context) throws InvoiceApiException {
        return insertExternalChargeForInvoiceAndBundle(accountId, invoiceId, null, amount, description, effectiveDate, currency, context);
    }

    @Override
    public InvoiceItem insertExternalChargeForInvoiceAndBundle(final UUID accountId, @Nullable final UUID invoiceId, @Nullable final UUID bundleId,
                                                               final BigDecimal amount, @Nullable final String description, final LocalDate effectiveDate,
                                                               final Currency currency, final CallContext context) throws InvoiceApiException {
        if (amount == null || amount.compareTo(BigDecimal.ZERO) <= 0) {
            throw new InvoiceApiException(ErrorCode.EXTERNAL_CHARGE_AMOUNT_INVALID, amount);
        }

        return dao.insertExternalCharge(accountId, invoiceId, bundleId, description, amount, effectiveDate, currency, internalCallContextFactory.createInternalCallContext(accountId, context));
    }

    @Override
    public InvoiceItem getCreditById(final UUID creditId, final TenantContext context) throws InvoiceApiException {
        final InvoiceItem creditItem = dao.getCreditById(creditId, internalCallContextFactory.createInternalTenantContext(context));
        if (creditItem == null) {
            throw new InvoiceApiException(ErrorCode.INVOICE_NO_SUCH_CREDIT, creditId);
        }

        return new CreditAdjInvoiceItem(creditItem.getId(), creditItem.getCreatedDate(), creditItem.getInvoiceId(), creditItem.getAccountId(),
                                        creditItem.getStartDate(), creditItem.getAmount().negate(), creditItem.getCurrency());
    }

    @Override
    public InvoiceItem insertCredit(final UUID accountId, final BigDecimal amount, final LocalDate effectiveDate,
                                    final Currency currency, final CallContext context) throws InvoiceApiException {
        return insertCreditForInvoice(accountId, null, amount, effectiveDate, currency, context);
    }

    @Override
    public InvoiceItem insertCreditForInvoice(final UUID accountId, final UUID invoiceId, final BigDecimal amount,
                                              final LocalDate effectiveDate, final Currency currency, final CallContext context) throws InvoiceApiException {
        if (amount == null || amount.compareTo(BigDecimal.ZERO) <= 0) {
            throw new InvoiceApiException(ErrorCode.CREDIT_AMOUNT_INVALID, amount);
        }

        return dao.insertCredit(accountId, invoiceId, amount, effectiveDate, currency, internalCallContextFactory.createInternalCallContext(accountId, context));
    }

    @Override
    public InvoiceItem insertInvoiceItemAdjustment(final UUID accountId, final UUID invoiceId, final UUID invoiceItemId,
                                                   final LocalDate effectiveDate, final CallContext context) throws InvoiceApiException {
        return insertInvoiceItemAdjustment(accountId, invoiceId, invoiceItemId, effectiveDate, null, null, context);
    }

    @Override
    public InvoiceItem insertInvoiceItemAdjustment(final UUID accountId, final UUID invoiceId, final UUID invoiceItemId,
                                                   final LocalDate effectiveDate, @Nullable final BigDecimal amount,
                                                   @Nullable final Currency currency, final CallContext context) throws InvoiceApiException {
        if (amount != null && amount.compareTo(BigDecimal.ZERO) <= 0) {
            throw new InvoiceApiException(ErrorCode.INVOICE_ITEM_ADJUSTMENT_AMOUNT_INVALID, amount);
        }

        return dao.insertInvoiceItemAdjustment(accountId, invoiceId, invoiceItemId, effectiveDate, amount, currency, internalCallContextFactory.createInternalCallContext(accountId, context));
    }

    @Override
    public void deleteCBA(final UUID accountId, final UUID invoiceId, final UUID invoiceItemId, final CallContext context) throws InvoiceApiException {
        dao.deleteCBA(accountId, invoiceId, invoiceItemId, internalCallContextFactory.createInternalCallContext(accountId, context));
    }

    @Override
    public String getInvoiceAsHTML(final UUID invoiceId, final TenantContext context) throws AccountApiException, IOException, InvoiceApiException {
        final Invoice invoice = getInvoice(invoiceId, context);
        if (invoice == null) {
            throw new InvoiceApiException(ErrorCode.INVOICE_NOT_FOUND, invoiceId);
        }

        final InternalTenantContext internalContext = internalCallContextFactory.createInternalTenantContext(context);
        final Account account = accountUserApi.getAccountById(invoice.getAccountId(), internalContext);

        // Check if this account has the MANUAL_PAY system tag
        boolean manualPay = false;
        final Map<String, Tag> accountTags = tagApi.getTags(account.getId(), ObjectType.ACCOUNT, internalContext);
        for (final Tag tag : accountTags.values()) {
            if (ControlTagType.MANUAL_PAY.getId().equals(tag.getTagDefinitionId())) {
                manualPay = true;
                break;
            }
        }

        return generator.generateInvoice(account, invoice, manualPay);
    }

    private void notifyBusOfInvoiceAdjustment(final UUID invoiceId, final UUID accountId, final UUID userToken, final InternalCallContext context) {
        try {
            eventBus.post(new DefaultInvoiceAdjustmentEvent(invoiceId, accountId, context.getUserToken(), context.getAccountRecordId(), context.getTenantRecordId()), context);
        } catch (EventBusException e) {
            log.warn("Failed to post adjustment event for invoice " + invoiceId, e);
        }
    }
}
