// ──────────────────────────────────────────────
// 🔒 GUARD: This module MUST NEVER be imported client-side.
// It contains secrets: DB tokens, JWT keys, AWS credentials, API tokens.
// ──────────────────────────────────────────────

// Build-time guard — Vite dead-code eliminates everything below when SSR=true.
// If this module is bundled client-side, it throws before any secrets are parsed.
if (!import.meta.env.SSR) {
  throw new Error(
    "[SERVER-ONLY] src/env/server.ts was imported client-side! " +
      "This module contains server-only secrets (database credentials, JWT keys, API tokens) " +
      "and must never be bundled in client code."
  );
}

// Runtime defense-in-depth — throws if somehow evaluated in a browser context.
if (typeof window !== "undefined") {
  throw new Error(
    "[SERVER-ONLY] src/env/server.ts was loaded in a browser context. " +
      "This is a critical security violation."
  );
}

import { z } from "zod";

const serverEnvSchema = z.object({
  NODE_ENV: z.enum(["development", "test", "production"]),
  JWT_SECRET_KEY: z.string().min(1),
  AWS_REGION: z.string().min(1),
  AWS_S3_BUCKET_NAME: z.string().min(1),
  MY_AWS_ACCESS_KEY: z.string().min(1),
  MY_AWS_SECRET_KEY: z.string().min(1),
  GOOGLE_CLIENT_SECRET: z.string().min(1),
  GITHUB_CLIENT_SECRET: z.string().min(1),
  EMAIL_SERVER: z.string().min(1),
  EMAIL_FROM: z.string().min(1),
  SENDINBLUE_KEY: z.string().min(1),
  TURSO_DB_URL: z.string().min(1),
  TURSO_DB_TOKEN: z.string().min(1),
  TURSO_LINEAGE_URL: z.string().min(1),
  TURSO_LINEAGE_TOKEN: z.string().min(1),
  TURSO_DB_API_TOKEN: z.string().min(1),
  LINEAGE_OFFLINE_SERIALIZATION_SECRET: z.string().min(1),
  GITEA_URL: z.string().min(1),
  GITEA_TOKEN: z.string().min(1),
  GITHUB_API_TOKEN: z.string().min(1),
  VITE_DOMAIN: z.string().min(1),
  VITE_AWS_BUCKET_STRING: z.string().min(1),
  VITE_DOWNLOAD_BUCKET_STRING: z.string().min(1),
  VITE_GOOGLE_CLIENT_ID: z.string().min(1),
  VITE_GOOGLE_CLIENT_ID_MAGIC_DELVE: z.string().min(1),
  VITE_GITHUB_CLIENT_ID: z.string().min(1),
  VITE_WEBSOCKET: z.string().min(1),
  VITE_INFILL_ENDPOINT: z.string().min(1),
  INFILL_BEARER_TOKEN: z.string().min(1),
  NESSA_DB_URL: z.string().min(1),
  NESSA_DB_TOKEN: z.string().min(1),
  // Clerk authentication — Nessa auth is now Clerk-backed. The
  // legacy self-issued JWT signing env var was removed.
  NESSA_CLERK_SECRET: z.string().min(1),
  NESSA_CLERK_JWT_ISSUER: z.string().min(1),
  // Clerk webhook signing secret (Svix). Used to verify `user.created` /
  // `user.updated` webhook payloads. Find it under Clerk Dashboard →
  // Webhooks → your endpoint → Signing Secret (starts with `whsec_`).
  NESSA_CLERK_WEBHOOK_SECRET: z.string().min(1),
  LINEAGE_JWT_SECRET: z.string().min(32),
  APPLE_CLIENT_ID_NESSA: z.string().min(1).optional(),
  APPLE_CLIENT_ID_LINEAGE: z.string().min(1).optional(),
  VITE_TURNSTILE_SITE_KEY: z.string().min(1),
  TURNSTILE_SECRET_KEY: z.string().min(1),
  NOOK_DB_URL: z.string().min(1),
  NOOK_DB_TOKEN: z.string().min(1),
  NOOK_LICENSE_PRIVATE_KEY: z.string().min(1),
  NOOK_STRIPE_SK: z.string().min(1),
  NOOK_STRIPE_WEBHOOK_SECRET: z.string().min(1),
  NOOK_STRIPE_PRICE_ID: z.string().min(1)
});

export type ServerEnv = z.infer<typeof serverEnvSchema>;

export const validateServerEnv = (
  envVars: Record<string, string | undefined>
): ServerEnv => {
  try {
    return serverEnvSchema.parse(envVars);
  } catch (error) {
    if (error instanceof z.ZodError) {
      const formattedErrors = error.format();
      const missingVars = Object.entries(formattedErrors)
        .filter(
          ([key, value]) =>
            key !== "_errors" &&
            typeof value === "object" &&
            value._errors?.length > 0 &&
            value._errors[0] === "Required"
        )
        .map(([key, _]) => key);

      const invalidVars = Object.entries(formattedErrors)
        .filter(
          ([key, value]) =>
            key !== "_errors" &&
            typeof value === "object" &&
            value._errors?.length > 0 &&
            value._errors[0] !== "Required"
        )
        .map(([key, value]) => ({
          key,
          error: value._errors[0]
        }));

      let errorMessage = "Environment validation failed:\n";

      if (missingVars.length > 0) {
        errorMessage += `Missing required variables: ${missingVars.join(", ")}\n`;
      }

      if (invalidVars.length > 0) {
        errorMessage += "Invalid values:\n";
        invalidVars.forEach(({ key, error }) => {
          errorMessage += `  ${key}: ${error}\n`;
        });
      }

      console.error(errorMessage);
      throw new Error(errorMessage);
    }
    console.error("Environment validation failed with unknown error:", error);
    throw new Error("Environment validation failed with unknown error");
  }
};

const validateAndExportEnv = (): ServerEnv => {
  try {
    const validated = validateServerEnv(process.env);
    console.log("✅ Environment validation successful");
    return validated;
  } catch (error) {
    console.error("❌ Environment validation failed:", error);
    throw error;
  }
};

export const env = validateAndExportEnv();

export const isMissingEnvVar = (varName: string): boolean => {
  return !process.env[varName] || process.env[varName]?.trim() === "";
};

export const getMissingEnvVars = (): string[] => {
  const requiredServerVars = [
    "NODE_ENV",
    "JWT_SECRET_KEY",
    "AWS_REGION",
    "AWS_S3_BUCKET_NAME",
    "MY_AWS_ACCESS_KEY",
    "MY_AWS_SECRET_KEY",
    "GOOGLE_CLIENT_SECRET",
    "GITHUB_CLIENT_SECRET",
    "EMAIL_SERVER",
    "EMAIL_FROM",
    "SENDINBLUE_KEY",
    "TURSO_DB_URL",
    "TURSO_DB_TOKEN",
    "TURSO_LINEAGE_URL",
    "TURSO_LINEAGE_TOKEN",
    "TURSO_DB_API_TOKEN",
    "LINEAGE_OFFLINE_SERIALIZATION_SECRET",
    "GITEA_URL",
    "GITEA_TOKEN",
    "GITHUB_API_TOKEN",
    "VITE_DOMAIN",
    "VITE_AWS_BUCKET_STRING",
    "VITE_DOWNLOAD_BUCKET_STRING",
    "VITE_GOOGLE_CLIENT_ID",
    "VITE_GOOGLE_CLIENT_ID_MAGIC_DELVE",
    "VITE_GITHUB_CLIENT_ID",
    "VITE_WEBSOCKET",
    "NESSA_DB_URL",
    "NESSA_DB_TOKEN",
    "NESSA_CLERK_SECRET",
    "NESSA_CLERK_JWT_ISSUER",
    "NESSA_CLERK_WEBHOOK_SECRET",
    "LINEAGE_JWT_SECRET"
  ];

  return requiredServerVars.filter((varName) => isMissingEnvVar(varName));
};