module transaction.service;

import handy_http_primitives;
import std.datetime;

import transaction.api;
import transaction.model;
import transaction.data;
import profile.data;
import account.model;
import util.money;
import util.pagination;

// Transactions Services

Page!TransactionsListItem getTransactions(ProfileDataSource ds, in PageRequest pageRequest) {
    Page!TransactionsListItem page = ds.getTransactionRepository()
        .findAll(pageRequest);
    return page; // Return an empty page for now!
}

void addTransaction2(ProfileDataSource ds, in AddTransactionPayload payload) {
    // TODO
}

void addTransaction(
    ProfileDataSource ds,
    SysTime timestamp,
    SysTime addedAt,
    ulong amount,
    Currency currency,
    string description,
    Optional!ulong vendorId,
    Optional!ulong categoryId,
    Optional!ulong creditedAccountId,
    Optional!ulong debitedAccountId,
    TransactionLineItem[] lineItems,
    string[] tags
) {
    if (creditedAccountId.isNull && debitedAccountId.isNull) {
        throw new Exception("At least one account must be linked to a transaction.");
    }
    auto journalEntryRepo = ds.getAccountJournalEntryRepository();
    auto txRepo = ds.getTransactionRepository();
    Transaction tx = txRepo.insert(
        timestamp,
        addedAt,
        amount,
        currency,
        description,
        vendorId,
        categoryId
    );
    if (creditedAccountId) {
        journalEntryRepo.insert(
            timestamp,
            creditedAccountId.value,
            tx.id,
            amount,
            AccountJournalEntryType.CREDIT,
            currency
        );
    }
    if (debitedAccountId) {
        journalEntryRepo.insert(
            timestamp,
            debitedAccountId.value,
            tx.id,
            amount,
            AccountJournalEntryType.DEBIT,
            currency
        );
    }
    if (tags.length > 0) {
        ds.getTransactionTagRepository().updateTags(tx.id, tags);
    }
}

// Vendors Services

TransactionVendor[] getAllVendors(ProfileDataSource ds) {
    return ds.getTransactionVendorRepository().findAll();
}

TransactionVendor getVendor(ProfileDataSource ds, ulong vendorId) {
    return ds.getTransactionVendorRepository().findById(vendorId)
        .orElseThrow(() => new HttpStatusException(HttpStatus.NOT_FOUND));
}

TransactionVendor createVendor(ProfileDataSource ds, in VendorPayload payload) {
    auto vendorRepo = ds.getTransactionVendorRepository();
    if (vendorRepo.existsByName(payload.name)) {
        throw new HttpStatusException(HttpStatus.BAD_REQUEST, "Vendor name is already in use.");
    }
    return vendorRepo.insert(payload.name, payload.description);
}

TransactionVendor updateVendor(ProfileDataSource ds, ulong vendorId, in VendorPayload payload) {
    TransactionVendorRepository repo = ds.getTransactionVendorRepository();
    TransactionVendor existingVendor = repo.findById(vendorId)
        .orElseThrow(() => new HttpStatusException(HttpStatus.NOT_FOUND));
    if (payload.name != existingVendor.name && repo.existsByName(payload.name)) {
        throw new HttpStatusException(
            HttpStatus.BAD_REQUEST,
            "Vendor name is already in use."
        );
    }
    return repo.updateById(vendorId, payload.name, payload.description);
}

void deleteVendor(ProfileDataSource ds, ulong vendorId) {
    ds.getTransactionVendorRepository().deleteById(vendorId);
}