"use client"

import { useCallback, useEffect, useRef, useLayoutEffect } from "react"
import { createPortal } from "react-dom"
import { X } from "lucide-react"
import { cn } from "@/lib/utils"

const sizeClasses = {
  sm: "max-w-sm",
  md: "max-w-md",
  lg: "max-w-lg",
  xl: "max-w-xl",
  full: "max-w-full w-full h-full m-0 rounded-none",
}

type ModalSize = keyof typeof sizeClasses

export interface ModalProps {
  isOpen: boolean
  onClose: () => void
  title?: string
  description?: string
  size?: ModalSize
  children?: React.ReactNode
  className?: string
  showCloseButton?: boolean
}

// Use useLayoutEffect for DOM reads/writes to avoid hydration mismatches
const useIsomorphicLayoutEffect = typeof window !== "undefined" ? useLayoutEffect : useEffect

export function Modal({
  isOpen,
  onClose,
  title,
  description,
  size = "md",
  children,
  className,
  showCloseButton = true,
}: ModalProps) {
  const modalRef = useRef<HTMLDivElement>(null)
  const previousActiveElement = useRef<HTMLElement | null>(null)

  // Escape handler
  const handleEscape = useCallback(
    (e: KeyboardEvent) => {
      if (e.key === "Escape") {
        onClose()
      }
    },
    [onClose],
  )

  useEffect(() => {
    if (!isOpen) return
    document.addEventListener("keydown", handleEscape)
    return () => document.removeEventListener("keydown", handleEscape)
  }, [isOpen, handleEscape])

  // Body scroll lock
  useEffect(() => {
    if (isOpen) {
      const originalOverflow = document.body.style.overflow
      document.body.style.overflow = "hidden"
      return () => {
        document.body.style.overflow = originalOverflow
      }
    }
  }, [isOpen])

  // Focus management: store previously focused element and restore on close
  useIsomorphicLayoutEffect(() => {
    if (isOpen) {
      previousActiveElement.current = document.activeElement as HTMLElement
      // Focus the modal header or the close button for accessibility
      const firstFocusable = modalRef.current?.querySelector<HTMLElement>(
        'button, [href], input, select, textarea, [tabindex]:not([tabindex="-1"])',
      )
      firstFocusable?.focus()
      return () => {
        previousActiveElement.current?.focus()
      }
    }
  }, [isOpen])

  // Focus trap
  useEffect(() => {
    if (!isOpen) return

    const handleTab = (e: KeyboardEvent) => {
      if (e.key !== "Tab" || !modalRef.current) return

      const focusableElements = modalRef.current.querySelectorAll<HTMLElement>(
        'button, [href], input, select, textarea, [tabindex]:not([tabindex="-1"])',
      )
      const first = focusableElements[0]
      const last = focusableElements[focusableElements.length - 1]

      if (e.shiftKey) {
        if (document.activeElement === first) {
          e.preventDefault()
          last?.focus()
        }
      } else {
        if (document.activeElement === last) {
          e.preventDefault()
          first?.focus()
        }
      }
    }

    document.addEventListener("keydown", handleTab)
    return () => document.removeEventListener("keydown", handleTab)
  }, [isOpen])

  if (!isOpen) return null

  return createPortal(
    <div className="fixed inset-0 z-50" aria-hidden={!isOpen}>
      {/* Overlay */}
      <div
        className="absolute inset-0 bg-black/50"
        onClick={onClose}
        aria-hidden="true"
      />

      {/* Modal wrapper */}
      <div className="absolute inset-0 flex items-center justify-center overflow-y-auto p-4">
        <div
          ref={modalRef}
          role="dialog"
          aria-modal="true"
          aria-labelledby={title ? "modal-title" : undefined}
          aria-describedby={description ? "modal-description" : undefined}
          className={cn(
            "relative w-full rounded-xl border border-border bg-background text-text shadow-xl",
            size !== "full" && "my-auto max-h-[90vh] flex flex-col",
            size === "full" && "h-full flex flex-col",
            sizeClasses[size],
            className,
          )}
        >
          {/* Header */}
          {(title || showCloseButton) && (
            <div className="flex items-center justify-between gap-4 border-b border-border px-5 py-4 shrink-0">
              <div className="flex-1 min-w-0">
                {title && (
                  <h2
                    id="modal-title"
                    className="text-base font-semibold text-text truncate"
                  >
                    {title}
                  </h2>
                )}
                {description && (
                  <p id="modal-description" className="mt-0.5 text-sm text-text/60">
                    {description}
                  </p>
                )}
              </div>
              {showCloseButton && (
                <button
                  type="button"
                  onClick={onClose}
                  className="shrink-0 rounded-md p-1.5 text-text/50 transition-colors hover:bg-text/5 hover:text-text focus:outline-none focus-visible:ring-2 focus-visible:ring-primary/50 cursor-pointer"
                  aria-label="Close modal"
                >
                  <X className="h-4 w-4" />
                </button>
              )}
            </div>
          )}

          {/* Body */}
          <div className={cn("flex-1 overflow-y-auto", !title && !showCloseButton && "p-5", title || showCloseButton ? "px-5 py-4" : "")}>
            {children}
          </div>
        </div>
      </div>
    </div>,
    document.body,
  )
}