import { z } from "zod";

const supportedLocales = ["de", "en"] as const;

const configSchema = z.object({
  port: z.coerce.number().min(1).max(65535).default(8000),
  logLevel: z.enum(["debug", "info", "warn", "error"]).default("info"),
  databasePath: z.string().default("./data/contracts.db"),
  paperlessBaseUrl: z.string().url().optional(),
  paperlessToken: z.string().min(1).optional(),
  paperlessExternalUrl: z.string().url().optional(),
  paperlessWebhookUrl: z.string().url().optional(),
  appExternalUrl: z.string().url().optional(),
  appLocale: z.enum(supportedLocales).default("de"),
  schedulerIntervalMinutes: z.coerce.number().min(5).default(60),
  alertDaysBefore: z.coerce.number().min(1).default(30),
  mailServer: z.string().optional(),
  mailPort: z.coerce.number().min(1).max(65535).default(587),
  mailUsername: z.string().optional(),
  mailPassword: z.string().optional(),
  mailUseTls: z.coerce.boolean().default(true),
  mailFrom: z.string().email().optional(),
  mailTo: z.string().email().optional(),
  authUsername: z.string().optional(),
  authPassword: z.string().optional(),
  authJwtSecret: z.string().optional(),
  authTokenExpiresInHours: z.coerce.number().min(1).max(168).default(12),
  ntfyServerUrl: z.string().url().optional(),
  ntfyTopic: z.string().min(1).optional(),
  ntfyToken: z.string().optional(),
  ntfyPriority: z.string().optional(),
  icalSecret: z.string().optional(),
  aiEnabled: z.coerce.boolean().default(false),
  aiProvider: z.enum(["openai", "openai-compatible", "gemini"]).optional(),
  aiBaseUrl: z.string().url().optional(),
  aiModel: z.string().min(1).optional(),
  aiApiKey: z.string().min(1).optional(),
  aiSystemPrompt: z.string().optional(),
  aiTimeoutSeconds: z.coerce.number().min(5).max(300).default(60),
  aiMaxTokens: z.coerce.number().min(256).max(16000).default(2000),
  paperlessWebhookSecret: z.string().min(10).optional()
});

function parseBoolean(value: string | undefined, fallback: boolean): boolean {
  if (value === undefined) {
    return fallback;
  }
  return ["1", "true", "yes", "on"].includes(value.toLowerCase());
}

function readEnv(name: string): string | undefined {
  const value = process.env[name];
  if (value === undefined) {
    return undefined;
  }
  return value.trim().length > 0 ? value : undefined;
}

const rawConfig = {
  port: readEnv("PORT"),
  logLevel: readEnv("LOG_LEVEL"),
  databasePath: readEnv("DATABASE_PATH"),
  paperlessBaseUrl: readEnv("PAPERLESS_BASE_URL"),
  paperlessToken: readEnv("PAPERLESS_TOKEN"),
  paperlessExternalUrl: readEnv("PAPERLESS_EXTERNAL_URL"),
  paperlessWebhookUrl: readEnv("PAPERLESS_WEBHOOK_URL"),
  appExternalUrl: readEnv("APP_EXTERNAL_URL"),
  appLocale: readEnv("APP_LOCALE"),
  schedulerIntervalMinutes: readEnv("SCHEDULER_INTERVAL_MINUTES"),
  alertDaysBefore: readEnv("ALERT_DAYS_BEFORE"),
  mailServer: readEnv("MAIL_SERVER"),
  mailPort: readEnv("MAIL_PORT"),
  mailUsername: readEnv("MAIL_USERNAME"),
  mailPassword: readEnv("MAIL_PASSWORD"),
  mailUseTls: parseBoolean(readEnv("MAIL_USE_TLS"), true),
  mailFrom: readEnv("MAIL_FROM"),
  mailTo: readEnv("MAIL_TO"),
  authUsername: readEnv("AUTH_USERNAME"),
  authPassword: readEnv("AUTH_PASSWORD"),
  authJwtSecret: readEnv("AUTH_JWT_SECRET"),
  authTokenExpiresInHours: readEnv("AUTH_TOKEN_EXPIRES_IN_HOURS"),
  ntfyServerUrl: readEnv("NTFY_SERVER_URL"),
  ntfyTopic: readEnv("NTFY_TOPIC"),
  ntfyToken: readEnv("NTFY_TOKEN"),
  ntfyPriority: readEnv("NTFY_PRIORITY"),
  icalSecret: readEnv("ICAL_SECRET"),
  aiEnabled: parseBoolean(readEnv("AI_ENABLED"), false),
  aiProvider: readEnv("AI_PROVIDER"),
  aiBaseUrl: readEnv("AI_BASE_URL"),
  aiModel: readEnv("AI_MODEL"),
  aiApiKey: readEnv("AI_API_KEY"),
  aiSystemPrompt: readEnv("AI_SYSTEM_PROMPT"),
  aiTimeoutSeconds: readEnv("AI_TIMEOUT_SECONDS"),
  aiMaxTokens: readEnv("AI_MAX_TOKENS"),
  paperlessWebhookSecret: readEnv("PAPERLESS_WEBHOOK_SECRET")
};

export type AppConfig = z.infer<typeof configSchema>;

export const config: AppConfig = configSchema.parse(rawConfig);