/**
 * Menubar for the canvas page: Project (Import/Export), Edit (Undo/Redo, Duplicate/Copy/Paste, Rename), View (Fit View, Minimap).
 */

import React, { useCallback, useEffect, useMemo, useRef, useState } from 'react'
import { Link, useParams } from 'react-router-dom'
import {
  Menubar,
  MenubarContent,
  MenubarItem,
  MenubarMenu,
  MenubarSeparator,
  MenubarTrigger
} from '@/components/ui/menubar'
import { Kbd, KbdGroup } from '@/components/ui/kbd'
import { usePlatform } from '@/app/kosmos/KosmosContext'
import { ArrowLeft, ClipboardPaste, Copy, CopyPlus, Download, FolderOpen, Pencil, Redo2, Undo2 } from 'lucide-react'
import { Input } from '@/components/ui/input'

export type CanvasMenubarProps = {
  onImport: () => void
  onExport: () => void
  undo: () => void
  redo: () => void
  canUndo: boolean
  canRedo: boolean
  onDuplicate?: () => void
  onCopy?: () => void
  onPaste?: () => void
  canDuplicate?: boolean
  canCopy?: boolean
  onFitView?: () => void
}

const UNDO_KEYS = { key: 'z', shiftKey: false }
const REDO_KEYS = { key: 'z', shiftKey: true }

function matchKey(ev: KeyboardEvent, want: { key: string; shiftKey: boolean }) {
  const mod = ev.ctrlKey || ev.metaKey
  return ev.key.toLowerCase() === want.key && !!mod && !!ev.shiftKey === want.shiftKey
}

export function CanvasMenubar({
  onImport,
  onExport,
  undo,
  redo,
  canUndo,
  canRedo,
  onDuplicate,
  onCopy,
  onPaste,
  canDuplicate = false,
  canCopy = false,
  onFitView,
}: CanvasMenubarProps) {
  const { projectId } = useParams<{ projectId: string }>()
  const { projects, renameProject } = usePlatform()
  const projectName = useMemo(
    () => (projectId ? projects.find((p) => p.id === projectId)?.name ?? null : null),
    [projectId, projects]
  )

  const [isRenamingProject, setIsRenamingProject] = useState(false)
  const [renameValue, setRenameValue] = useState('')
  const renameInputRef = useRef<HTMLInputElement>(null)
  const ignoreNextBlurRef = useRef(false)

  useEffect(() => {
    if (isRenamingProject) {
      setRenameValue(projectName ?? '')
      ignoreNextBlurRef.current = true
      // Delay focus so the Project dropdown can close first and not steal focus back (which would trigger blur)
      const t = setTimeout(() => {
        renameInputRef.current?.focus()
        renameInputRef.current?.select()
      }, 100)
      return () => clearTimeout(t)
    }
  }, [isRenamingProject, projectName])

  const applyRename = useCallback(() => {
    if (!projectId || !renameProject) return
    const trimmed = renameValue.trim()
    if (trimmed) renameProject(projectId, trimmed)
    setIsRenamingProject(false)
  }, [projectId, renameProject, renameValue])

  const cancelRename = useCallback(() => {
    setIsRenamingProject(false)
  }, [])

  const handleRenameBlur = useCallback(() => {
    if (ignoreNextBlurRef.current) {
      ignoreNextBlurRef.current = false
      return
    }
    applyRename()
  }, [applyRename])

  useEffect(() => {
    const onKeyDown = (ev: KeyboardEvent) => {
      if (matchKey(ev, UNDO_KEYS)) {
        if (canUndo) {
          ev.preventDefault()
          ev.stopPropagation()
          undo()
        }
        return
      }
      if (matchKey(ev, REDO_KEYS)) {
        if (canRedo) {
          ev.preventDefault()
          ev.stopPropagation()
          redo()
        }
      }
    }
    window.addEventListener('keydown', onKeyDown, true)
    return () => window.removeEventListener('keydown', onKeyDown, true)
  }, [undo, redo, canUndo, canRedo])

  return (
    <div className="relative flex h-9 w-full shrink-0 items-center border-b border-border/40 bg-background">
      <Menubar className="flex-1 shrink-0 rounded-none border-0 border-b-0 bg-transparent p-0 shadow-none">
        <Link
          to="/projects"
          aria-label="Back to projects"
          className="flex shrink-0 items-center rounded-sm px-2 py-1 ml-1 text-sm outline-none focus:bg-accent focus:text-accent-foreground hover:bg-accent hover:text-accent-foreground"
        >
          <ArrowLeft className="size-4" />
        </Link>
        <MenubarMenu>
          <MenubarTrigger className="font-normal text-muted-foreground">Project</MenubarTrigger>
          <MenubarContent>
                {projectId && (
              <>
                <MenubarItem
                  onClick={() => setIsRenamingProject(true)}
                  className="gap-2"
                >
                  <Pencil className="h-4 w-4" />
                  Rename
                </MenubarItem>
                <MenubarSeparator />
              </>
            )}
            <MenubarItem onClick={onImport} className="gap-2">
              <FolderOpen className="h-4 w-4" />
              Import…
            </MenubarItem>
            <MenubarItem onClick={onExport} className="gap-2">
              <Download className="h-4 w-4" />
              Export…
            </MenubarItem>
          </MenubarContent>
        </MenubarMenu>
        <MenubarMenu>
          <MenubarTrigger className="font-normal text-muted-foreground">Edit</MenubarTrigger>
          <MenubarContent>
            <MenubarItem onClick={undo} disabled={!canUndo} className="gap-2">
              <Undo2 className="h-4 w-4" />
              Undo
              <span className="ml-auto pl-4">
                <KbdGroup>
                  <Kbd>⌘ + Z</Kbd>
                </KbdGroup>
              </span>
            </MenubarItem>
            <MenubarItem onClick={redo} disabled={!canRedo} className="gap-2">
              <Redo2 className="h-4 w-4" />
              Redo
              <span className="ml-auto pl-4">
                <KbdGroup>
                  <Kbd>⌘ + ⇧ + Z</Kbd>
                </KbdGroup>
              </span>
            </MenubarItem>
            {(onDuplicate != null || onCopy != null || onPaste != null) && <MenubarSeparator />}
            {onDuplicate != null && (
              <MenubarItem onClick={onDuplicate} disabled={!canDuplicate} className="gap-2">
                <CopyPlus className="h-4 w-4" />
                Duplicate
                <span className="ml-auto pl-4">
                  <KbdGroup>
                    <Kbd>⌘D</Kbd>
                  </KbdGroup>
                </span>
              </MenubarItem>
            )}
            {onCopy != null && (
              <MenubarItem onClick={onCopy} disabled={!canCopy} className="gap-2">
                <Copy className="h-4 w-4" />
                Copy
                <span className="ml-auto pl-4">
                  <KbdGroup>
                    <Kbd>⌘C</Kbd>
                  </KbdGroup>
                </span>
              </MenubarItem>
            )}
            {onPaste != null && (
              <MenubarItem onClick={onPaste} className="gap-2">
                <ClipboardPaste className="h-4 w-4" />
                Paste
                <span className="ml-auto pl-4">
                  <KbdGroup>
                    <Kbd>⌘V</Kbd>
                  </KbdGroup>
                </span>
              </MenubarItem>
            )}
          </MenubarContent>
        </MenubarMenu>
        <MenubarMenu>
          <MenubarTrigger className="font-normal text-muted-foreground">View</MenubarTrigger>
          <MenubarContent>
            {onFitView && (
              <MenubarItem onClick={onFitView} className="gap-2">
                Fit View
                <span className="ml-auto pl-4">
                  <KbdGroup>
                    <Kbd>⌘0</Kbd>
                  </KbdGroup>
                </span>
              </MenubarItem>
            )}
          </MenubarContent>
        </MenubarMenu>
      </Menubar>
      {projectId && (
        <div className="absolute left-1/2 -translate-x-1/2 flex justify-center max-w-[40%] min-w-[120px]">
          {isRenamingProject ? (
            <Input
              ref={renameInputRef}
              type="text"
              value={renameValue}
              onChange={(e) => setRenameValue(e.target.value)}
              onKeyDown={(e) => {
                if (e.key === 'Enter') {
                  e.preventDefault()
                  applyRename()
                } else if (e.key === 'Escape') {
                  e.preventDefault()
                  cancelRename()
                }
              }}
              onBlur={handleRenameBlur}
              className="h-7 text-sm font-medium text-center font-serif"
              aria-label="Project name"
            />
          ) : (
            <span className="pointer-events-none truncate text-sm font-medium text-foreground font-serif">
              {projectName ?? 'Untitled'}
            </span>
          )}
        </div>
      )}
    </div>
  )
}