import type { ImapConfig } from "./imap";
import type { SmtpConfig } from "./smtp";

export interface AccountInfo {
  slot: 1 | 2 | 3;
  label: string;
  imap: ImapConfig;
  smtp: SmtpConfig | null;
}

interface ConfigReader {
  get(key: string): unknown;
}

function readString(cfg: ConfigReader, key: string): string {
  const value = cfg.get(key);
  return typeof value === "string" ? value.trim() : "";
}

function readNumber(cfg: ConfigReader, key: string, fallback: number): number {
  const value = Number(cfg.get(key));
  return Number.isInteger(value) && value >= 1 && value <= 65535 ? value : fallback;
}

function readSlot(cfg: ConfigReader, n: 1 | 2 | 3): AccountInfo | null {
  const label = readString(cfg, `account${n}Label`);
  const host = readString(cfg, `account${n}ImapHost`);
  const user = readString(cfg, `account${n}User`);
  const passwordValue = cfg.get(`account${n}Password`);
  const password = typeof passwordValue === "string" ? passwordValue : "";

  if (!host || !user || !password) return null;

  const smtpHost = readString(cfg, `account${n}SmtpHost`);
  return {
    slot: n,
    label: label || `Account ${n}`,
    imap: {
      host,
      port: readNumber(cfg, `account${n}ImapPort`, 993),
      user,
      password,
    },
    smtp: smtpHost
      ? {
          host: smtpHost,
          port: readNumber(cfg, `account${n}SmtpPort`, 587),
          user,
          password,
        }
      : null,
  };
}

export function getConfiguredAccounts(cfg: ConfigReader): AccountInfo[] {
  return ([1, 2, 3] as const)
    .map((n) => readSlot(cfg, n))
    .filter((account): account is AccountInfo => account !== null);
}

export function resolveAccount(cfg: ConfigReader, accountRef: string): AccountInfo {
  const accounts = getConfiguredAccounts(cfg);
  if (accounts.length === 0) {
    throw new Error(
      "No email accounts configured. Add IMAP Host, Email Address, and Password for at least one account in plugin settings.",
    );
  }

  const ref = accountRef.trim();
  if (!ref || ref.toLowerCase() === "default") return accounts[0];

  // Accept only an exact slot number. Strings such as "2foo" must not resolve to slot 2.
  if (/^[1-3]$/.test(ref)) {
    const slotNumber = Number(ref);
    const found = accounts.find((account) => account.slot === slotNumber);
    if (!found) throw new Error(`Account ${slotNumber} is not configured. Check plugin settings.`);
    return found;
  }

  const labelMatches = accounts.filter(
    (account) => account.label.toLowerCase() === ref.toLowerCase(),
  );
  if (labelMatches.length === 1) return labelMatches[0];
  if (labelMatches.length > 1) {
    const slots = labelMatches.map((account) => account.slot).join(", ");
    throw new Error(
      `Account label "${ref}" is ambiguous because it is used by slots ${slots}. Use a slot number or assign unique labels.`,
    );
  }

  const list = accounts.map((account) => `${account.slot} (${account.label})`).join(", ");
  throw new Error(`Account "${ref}" not found. Configured accounts: ${list}`);
}

import type { ImapConfig } from "./imap";
import type { SmtpConfig } from "./smtp";

export interface AccountInfo {
  slot: 1 | 2 | 3;
  label: string;
  imap: ImapConfig;
  smtp: SmtpConfig | null;
}

interface ConfigReader {
  get(key: string): unknown;
}

function readString(cfg: ConfigReader, key: string): string {
  const value = cfg.get(key);
  return typeof value === "string" ? value.trim() : "";
}

function readNumber(cfg: ConfigReader, key: string, fallback: number): number {
  const value = Number(cfg.get(key));
  return Number.isInteger(value) && value >= 1 && value <= 65535 ? value : fallback;
}

function readSlot(cfg: ConfigReader, n: 1 | 2 | 3): AccountInfo | null {
  const label = readString(cfg, `account${n}Label`);
  const host = readString(cfg, `account${n}ImapHost`);
  const user = readString(cfg, `account${n}User`);
  const passwordValue = cfg.get(`account${n}Password`);
  const password = typeof passwordValue === "string" ? passwordValue : "";

  if (!host || !user || !password) return null;

  const smtpHost = readString(cfg, `account${n}SmtpHost`);
  return {
    slot: n,
    label: label || `Account ${n}`,
    imap: {
      host,
      port: readNumber(cfg, `account${n}ImapPort`, 993),
      user,
      password,
    },
    smtp: smtpHost
      ? {
          host: smtpHost,
          port: readNumber(cfg, `account${n}SmtpPort`, 587),
          user,
          password,
        }
      : null,
  };
}

export function getConfiguredAccounts(cfg: ConfigReader): AccountInfo[] {
  return ([1, 2, 3] as const)
    .map((n) => readSlot(cfg, n))
    .filter((account): account is AccountInfo => account !== null);
}

export function resolveAccount(cfg: ConfigReader, accountRef: string): AccountInfo {
  const accounts = getConfiguredAccounts(cfg);
  if (accounts.length === 0) {
    throw new Error(
      "No email accounts configured. Add IMAP Host, Email Address, and Password for at least one account in plugin settings.",
    );
  }

  const ref = accountRef.trim();
  if (!ref || ref.toLowerCase() === "default") return accounts[0];

  // Accept only an exact slot number. Strings such as "2foo" must not resolve to slot 2.
  if (/^[1-3]$/.test(ref)) {
    const slotNumber = Number(ref);
    const found = accounts.find((account) => account.slot === slotNumber);
    if (!found) throw new Error(`Account ${slotNumber} is not configured. Check plugin settings.`);
    return found;
  }

  const labelMatches = accounts.filter(
    (account) => account.label.toLowerCase() === ref.toLowerCase(),
  );
  if (labelMatches.length === 1) return labelMatches[0];
  if (labelMatches.length > 1) {
    const slots = labelMatches.map((account) => account.slot).join(", ");
    throw new Error(
      `Account label "${ref}" is ambiguous because it is used by slots ${slots}. Use a slot number or assign unique labels.`,
    );
  }

  const list = accounts.map((account) => `${account.slot} (${account.label})`).join(", ");
  throw new Error(`Account "${ref}" not found. Configured accounts: ${list}`);
}