env.ts

import { z } from 'zod'

/**
 * Preprocessor that normalizes empty strings to undefined.
 * Railway and some platforms may set env vars to "" instead of leaving them unset.
 * This ensures `.default()` and `.optional()` work as expected.
 */
const emptyToUndefined = z.preprocess(
  (val) => (typeof val === 'string' && val.trim() === '' ? undefined : val),
  z.string(),
)

/**
 * Detect whether the current Railway environment is a PR/preview environment.
 * Production and long-lived environments must provide explicit BETTER_AUTH_URL.
 */
export function isRailwayPreviewEnvironment(environmentName?: string): boolean {
  const name = environmentName?.toLowerCase().trim() ?? ''

  if (!name) return false

  // Never treat production as preview.
  if (name === 'production' || name === 'prod') return false

  return (
    name.startsWith('pr')
    ||
    /^pr(?:-|\d)/.test(name)
    || name.includes('pr-')
    || name.includes('pr ')
    || name.includes('pull request')
    || name.includes('pull-request')
    || name.includes('preview')
  )
}

const envSchema = z
  .object({
    DATABASE_URL: z.url(),
    BETTER_AUTH_SECRET: emptyToUndefined.pipe(z.string().min(32, 'BETTER_AUTH_SECRET must be at least 32 characters')),
    BETTER_AUTH_URL: emptyToUndefined.pipe(z.url()).optional(),
    /** Railway environment metadata for PR/preview detection. */
    RAILWAY_ENVIRONMENT_NAME: emptyToUndefined.optional(),
    /** PR number provided by Railway for GitHub-triggered deployments. */
    RAILWAY_GIT_PR_NUMBER: emptyToUndefined.pipe(z.string().regex(/^\d+$/, 'RAILWAY_GIT_PR_NUMBER must be numeric')).optional(),
    /** Public domain generated by Railway for the current deployment. */
    RAILWAY_PUBLIC_DOMAIN: emptyToUndefined.optional(),
    S3_ENDPOINT: z.url(),
    S3_ACCESS_KEY: emptyToUndefined.pipe(z.string().min(1)),
    S3_SECRET_KEY: emptyToUndefined.pipe(z.string().min(1)),
    S3_BUCKET: emptyToUndefined.pipe(z.string().min(1)),
    S3_REGION: emptyToUndefined.pipe(z.string().min(1)).optional().default('us-east-1'),
    /** Use path-style S3 URLs. Required for MinIO (local dev), must be `false` for Railway Buckets / AWS S3. */
    S3_FORCE_PATH_STYLE: z.preprocess(
      (val) => (typeof val === 'string' && val.trim() === '' ? undefined : val === 'true' || val === undefined),
      z.boolean().default(true),
    ),
    /** IP address of the trusted reverse proxy (e.g., Railway, Cloudflare). When set, X-Forwarded-For is trusted for rate limiting. */
    TRUSTED_PROXY_IP: z.string().min(1).optional(),
    /** Slug of the demo organization. When set, write operations are blocked for this org. */
    DEMO_ORG_SLUG: emptyToUndefined.optional(),
    /** Fine-grained GitHub PAT with Issues:write scope. When set (along with GITHUB_FEEDBACK_REPO), enables in-app feedback. */
    GITHUB_FEEDBACK_TOKEN: emptyToUndefined.pipe(z.string().min(1)).optional(),
    /** GitHub repo in "owner/repo" format for feedback issues. */
    GITHUB_FEEDBACK_REPO: emptyToUndefined.pipe(z.string().regex(/^[^/]+\/[^/]+$/, 'Must be in "owner/repo" format')).optional(),
  })
  .superRefine((data, ctx) => {
    const isPreview = isRailwayPreviewEnvironment(data.RAILWAY_ENVIRONMENT_NAME)

    if (!isPreview && !data.BETTER_AUTH_URL) {
      ctx.addIssue({
        code: z.ZodIssueCode.custom,
        path: ['BETTER_AUTH_URL'],
        message: 'BETTER_AUTH_URL is required outside Railway PR/preview environments',
      })
    }
  })

/**
 * Validated environment variables. Uses lazy initialization so the schema
 * is only parsed on first access at runtime — not at import time. This
 * prevents build-time prerendering from failing when env vars aren't
 * available (e.g., Railway injects variables only at deploy time, not
 * during the build phase).
 */
export const env = new Proxy({} as z.infer<typeof envSchema>, {
  get(_, prop: string | symbol) {
    // During build-time prerendering, env vars aren't available.
    // Return safe defaults so the prerenderer can boot without crashing.
    if (import.meta.prerender) {
      return ''
    }

    if (typeof prop === 'symbol') return undefined

    // Parse once on first access, then cache for all subsequent reads
    if (!(globalThis as Record<string, unknown>).__env) {
      const result = envSchema.safeParse(process.env)
      if (!result.success) {
        const missing = result.error.issues
          .map(i => `  - ${i.path.join('.')}: ${i.message}`)
          .join('\n')
        console.error(
          `\n[Applirank] ❌ Missing or invalid environment variables:\n${missing}\n\n` +
          `Ensure these variables are set in your Railway service (Settings → Variables).\n` +
          `Required: DATABASE_URL, BETTER_AUTH_SECRET, S3_ENDPOINT, S3_ACCESS_KEY, S3_SECRET_KEY, S3_BUCKET\n` +
          `Required outside Railway PR/preview environments: BETTER_AUTH_URL\n` +
          `Optional: S3_REGION (default: us-east-1), S3_FORCE_PATH_STYLE (default: true), TRUSTED_PROXY_IP, DEMO_ORG_SLUG\n`,
        )
        throw result.error
      }
      ;(globalThis as Record<string, unknown>).__env = result.data
    }

    return ((globalThis as Record<string, unknown>).__env as Record<string, unknown>)[prop]
  },
})