import type { ActionCtx } from "../_generated/server";
import type { Id } from "../_generated/dataModel";
import { internal } from "../_generated/api";
import { getAccountBalances, getTransactions } from "../comdirect/client";
import { mapComdirectTransaction } from "../lib/comdirectMap";
import type {
  BankDataProvider,
  NormalizedAccount,
  NormalizedBalance,
  NormalizedTransaction,
} from "./types";

export function hasComdirectCredentials(): boolean {
  return Boolean(process.env.COMDIRECT_CLIENT_ID && process.env.COMDIRECT_CLIENT_SECRET);
}

export function isRestFallbackError(error: unknown): boolean {
  if (!(error instanceof Error)) return true;
  const msg = error.message.toLowerCase();
  if (msg.includes("nicht konfiguriert")) return true;
  if (msg.includes("session nicht aktiv")) return true;
  if (msg.includes("oauth fehlgeschlagen")) return true;
  if (msg.includes("fehlgeschlagen: 5")) return true;
  if (msg.includes("fehlgeschlagen: 401")) return true;
  if (msg.includes("fehlgeschlagen: 403")) return true;
  if (msg.includes("network") || msg.includes("fetch")) return true;
  if (msg.includes("clientcredentials")) return true;
  return false;
}

type ComdirectProviderContext = {
  ctx: ActionCtx;
  userId: Id<"users">;
};

export async function createComdirectRestProvider(
  context: ComdirectProviderContext,
): Promise<BankDataProvider> {
  const { ctx, userId } = context;

  const clientId = process.env.COMDIRECT_CLIENT_ID;
  const clientSecret = process.env.COMDIRECT_CLIENT_SECRET;
  if (!clientId || !clientSecret) {
    throw new Error("comdirect API-Zugangsdaten nicht konfiguriert");
  }

  const session = await ctx.runQuery(internal.comdirect.internal.getSession, { userId });
  if (!session?.accessToken || !session.secondaryActive) {
    throw new Error("comdirect-Session nicht aktiv. Bitte erneut anmelden.");
  }

  const accessToken = session.accessToken;
  const sessionUuid = session.sessionUuid;

  return {
    name: "comdirect",

    async getAccounts(): Promise<NormalizedAccount[]> {
      const balances = await getAccountBalances(accessToken, sessionUuid);
      return (balances.values ?? []).flatMap((item) => {
        const account = item.account as {
          accountId?: string;
          iban?: string;
          accountType?: { text?: string };
        };
        const accountIdExternal = account?.accountId;
        if (!accountIdExternal) return [];
        const balanceValue = Number((item.balance as { value?: string })?.value ?? 0);
        return [
          {
            externalId: accountIdExternal,
            name: account.accountType?.text ?? "comdirect Konto",
            iban: account.iban,
            balance: balanceValue,
            currency: "EUR",
          },
        ];
      });
    },

    async getBalance(accountExternalId: string): Promise<NormalizedBalance> {
      const balances = await getAccountBalances(accessToken, sessionUuid);
      const match = (balances.values ?? []).find((item) => {
        const account = item.account as { accountId?: string };
        return account?.accountId === accountExternalId;
      });
      if (!match) throw new Error(`Konto ${accountExternalId} nicht gefunden`);
      return {
        externalId: accountExternalId,
        balance: Number((match.balance as { value?: string })?.value ?? 0),
        currency: "EUR",
      };
    },

    async getTransactions(
      accountExternalId: string,
      from: string,
      to: string,
    ): Promise<NormalizedTransaction[]> {
      const rows: NormalizedTransaction[] = [];
      for (const state of ["BOOKED", "NOTBOOKED"] as const) {
        let offset = 0;
        let matches = 0;
        do {
          const result = await getTransactions(accessToken, sessionUuid, accountExternalId, {
            transactionState: state,
            pagingFirst: offset,
            minBookingDate: from,
            maxBookingDate: to,
          });
          matches = result.paging.matches;
          for (const tx of result.values ?? []) {
            const mapped = mapComdirectTransaction(
              tx as Parameters<typeof mapComdirectTransaction>[0],
              [],
              {
                enabled: true,
                categoryNames: ["Gehalt & Besoldung"],
                dayThreshold: 25,
              },
            );
            rows.push({
              bookingDate: mapped.bookingDate,
              valueDate: mapped.valueDate,
              description: mapped.description,
              counterparty: mapped.counterparty,
              amount: mapped.amount,
              vorgang: mapped.vorgang,
              isPending: mapped.isPending,
              rawText: mapped.rawText,
              externalRef: mapped.externalRef,
            });
          }
          offset += result.values?.length ?? 0;
        } while (offset < matches);
      }
      return rows;
    },
  };
}

export async function fetchComdirectData(
  ctx: ActionCtx,
  userId: Id<"users">,
  from: string,
  to: string,
  filterAccountId: Id<"accounts"> | undefined,
  ownNames: string[],
  salaryShift: {
    enabled: boolean;
    categoryNames: string[];
    dayThreshold: number;
  },
): Promise<{
  accounts: NormalizedAccount[];
  transactionsByAccount: Map<string, NormalizedTransaction[]>;
}> {
  const provider = await createComdirectRestProvider({ ctx, userId });
  const accounts = await provider.getAccounts();
  const transactionsByAccount = new Map<string, NormalizedTransaction[]>();

  for (const account of accounts) {
    if (filterAccountId) {
      const convexId = await ctx.runMutation(internal.bank.internal.upsertAccountFromProvider, {
        userId,
        externalId: account.externalId,
        name: account.name,
        iban: account.iban,
        balance: account.balance,
        currency: account.currency,
      });
      if (convexId !== filterAccountId) continue;
    }
    const rawTxs = await provider.getTransactions(account.externalId, from, to);
    const txs = rawTxs.map((tx) => {
      const mapped = mapComdirectTransaction(
        {
          bookingStatus: tx.isPending ? "NOTBOOKED" : "BOOKED",
          bookingDate: tx.bookingDate,
          valueDate: tx.valueDate,
          amount: { value: String(tx.amount) },
          remittanceInfo: tx.rawText,
          remitter: tx.counterparty ? { holderName: tx.counterparty } : undefined,
          transactionType: tx.vorgang ? { text: tx.vorgang } : undefined,
          reference: tx.externalRef,
        },
        ownNames,
        salaryShift,
      );
      return {
        bookingDate: mapped.bookingDate,
        valueDate: mapped.valueDate,
        description: mapped.description,
        counterparty: mapped.counterparty,
        amount: mapped.amount,
        vorgang: mapped.vorgang,
        isPending: mapped.isPending,
        rawText: mapped.rawText,
        externalRef: mapped.externalRef,
        categoryName: mapped.categoryName,
        assignedMonth: mapped.assignedMonth,
        effectiveMonth: mapped.effectiveMonth,
      };
    });
    transactionsByAccount.set(account.externalId, txs);
  }

  return { accounts, transactionsByAccount };
}