import path from "node:path"
import { fileURLToPath, pathToFileURL } from "node:url"

import { PrismaClient } from "@prisma/client"

declare global {
  var prisma: PrismaClient | undefined
}

// Resolve a robust DATABASE_URL for all runtimes (prod/dev)
const PROJECT_ROOT = process.cwd()
const PROJECT_ROOT_URL = (() => {
  const baseHref = pathToFileURL(PROJECT_ROOT).href
  return new URL(baseHref.endsWith("/") ? baseHref : `${baseHref}/`)
})()

function resolveFileUrl(url: string) {
  if (!url.startsWith("file:")) {
    return url
  }

  const filePath = url.slice("file:".length)
  if (filePath.startsWith("./") || filePath.startsWith("../")) {
    const normalized = path.normalize(filePath)
    const targetUrl = new URL(normalized, PROJECT_ROOT_URL)
    const absolutePath = fileURLToPath(targetUrl)
    if (!absolutePath.startsWith(PROJECT_ROOT)) {
      throw new Error(`DATABASE_URL path escapes project directory: ${filePath}`)
    }
    return `file:${absolutePath}`
  }
  if (!filePath.startsWith("/")) {
    return resolveFileUrl(`file:./${filePath}`)
  }
  return url
}

const resolvedDatabaseUrl = (() => {
  const envUrl = process.env.DATABASE_URL?.trim()
  if (envUrl && envUrl.length > 0) return resolveFileUrl(envUrl)
  // Fallbacks by environment to ensure correctness in containers
  if (process.env.NODE_ENV === "production") {
    return "file:/app/data/db.sqlite"
  }
  // In development, prefer a dedicated dev DB file
  return resolveFileUrl("file:./prisma/db.dev.sqlite")
})()

export const prisma =
  global.prisma ?? new PrismaClient({ datasources: { db: { url: resolvedDatabaseUrl } } })

if (process.env.NODE_ENV !== "production") {
  global.prisma = prisma
}

if (process.env.NODE_ENV !== "production") {
  // Helps detect mismatched DB path during dev server bootstrap
  // eslint-disable-next-line no-console
  console.log("[prisma] Using database:", resolvedDatabaseUrl)
}