import { useState, useEffect, useRef } from 'react'
import { Sparkle } from '@phosphor-icons/react'
import { Dialog, DialogContent, DialogDescription, DialogHeader, DialogTitle, DialogFooter } from '@/components/ui/dialog'
import { Button } from '@/components/ui/button'
import { Badge } from '@/components/ui/badge'
import { Textarea } from '@/components/ui/textarea'
import { formatShortcutDisplay } from '../hooks/appCommandCatalog'
import type { CommitMode } from '../hooks/useCommitFlow'
import { GitRepositorySelect } from './GitRepositorySelect'
import type { GitRepositoryOption } from '../utils/gitRepositories'
import { translate, type AppLocale } from '../lib/i18n'
import type { GitAuthorIdentity } from '../types'

type CommitDialogCopy = {
  title: string
  description: string
  actionLabel: string
  shortcutHint: string
}

const getDialogCopy = (commitMode: CommitMode): CommitDialogCopy => {
  const submitShortcut = formatShortcutDisplay({ display: '⌘↵' })

  if (commitMode === 'local') {
    return {
      title: 'Commit',
      description: 'This vault has no git remote configured. Tolaria will create a local commit only.',
      actionLabel: 'Commit',
      shortcutHint: `${submitShortcut} to commit locally`,
    }
  }

  return {
    title: 'Commit & Push',
    description: 'Review changed files and enter a commit message before committing and pushing.',
    actionLabel: 'Commit & Push',
    shortcutHint: `${submitShortcut} to commit`,
  }
}

const changedFilesLabel = (modifiedCount: number): string => (
  `${modifiedCount} file${modifiedCount !== 1 ? 's' : ''} changed`
)

const isSubmitShortcut = (event: React.KeyboardEvent): boolean => (
  event.key === 'Enter' && (event.metaKey || event.ctrlKey)
)

const isCloseShortcut = (event: React.KeyboardEvent): boolean => event.key === 'Escape'

const formatAuthorIdentity = (identity: GitAuthorIdentity): string => (
  `${identity.name} <${identity.email}>`
)

const formatOptionalAuthorIdentity = (identity: GitAuthorIdentity | null): string => (
  identity ? formatAuthorIdentity(identity) : ''
)

const focusMessageInput = (inputRef: React.RefObject<HTMLTextAreaElement | null>): void => {
  setTimeout(() => inputRef.current?.focus(), 50)
}

const generationButtonDisabled = ({
  isGenerating,
  modifiedCount,
  onGenerateMessage,
}: {
  isGenerating: boolean
  modifiedCount: number
  onGenerateMessage?: () => Promise<string> | string
}): boolean => !onGenerateMessage || isGenerating || modifiedCount === 0

const authorWarningText = (identity: GitAuthorIdentity, locale: AppLocale): string | null => {
  if (identity.warning === 'local_overrides_global') {
    return translate(locale, 'git.author.warning.localOverridesGlobal')
  }

  return null
}

const CommitAuthorIdentity = ({
  identity,
  locale,
}: {
  identity: GitAuthorIdentity | null
  locale: AppLocale
}) => {
  const hidden = identity === null
  const warningText = identity ? authorWarningText(identity, locale) : null

  return (
    <div className="space-y-1 text-xs" data-testid="commit-author-identity" hidden={hidden} aria-hidden={hidden}>
      <div className="flex items-center justify-between gap-3">
        <span className="font-medium text-muted-foreground">{translate(locale, 'git.author.label')}</span>
        <span className="truncate text-right font-mono text-[11px]">{formatOptionalAuthorIdentity(identity)}</span>
      </div>
      {warningText && (
        <p className="text-[11px] leading-4 text-amber-700 dark:text-amber-300">{warningText}</p>
      )}
    </div>
  )
}

function useGeneratedCommitMessage({
  generatedMessage,
  generatedMessageKey,
  inputRef,
  open,
  setMessage,
}: {
  generatedMessage?: string
  generatedMessageKey: number
  inputRef: React.RefObject<HTMLTextAreaElement | null>
  open: boolean
  setMessage: (message: string) => void
}) {
  useEffect(() => {
    if (!open || generatedMessageKey === 0 || !generatedMessage) return
    setMessage(generatedMessage)
    focusMessageInput(inputRef)
  }, [generatedMessage, generatedMessageKey, inputRef, open, setMessage])
}

function CommitMessageGenerateButton({
  isGeneratingMessage,
  locale,
  modifiedCount,
  onGenerateMessage,
  onGeneratedMessage,
}: {
  isGeneratingMessage: boolean
  locale: AppLocale
  modifiedCount: number
  onGenerateMessage?: () => Promise<string> | string
  onGeneratedMessage: (message: string) => void
}) {
  const handleGenerateMessage = async () => {
    const generated = await onGenerateMessage?.()
    if (generated) onGeneratedMessage(generated)
  }

  return (
    <Button
      type="button"
      variant="outline"
      onClick={() => { void handleGenerateMessage() }}
      disabled={generationButtonDisabled({ isGenerating: isGeneratingMessage, modifiedCount, onGenerateMessage })}
      aria-label={translate(locale, 'git.commitMessage.generateFromDiff')}
      title={translate(locale, 'git.commitMessage.generateFromDiff')}
    >
      <Sparkle size={14} weight="fill" className="shrink-0" />
      {translate(locale, isGeneratingMessage ? 'git.commitMessage.generating' : 'git.commitMessage.generate')}
    </Button>
  )
}

function CommitDialogActions({
  actionLabel,
  isGeneratingMessage,
  locale,
  message,
  modifiedCount,
  onClose,
  onGenerateMessage,
  onGeneratedMessage,
  onSubmit,
  shortcutHint,
}: CommitDialogCopy & {
  isGeneratingMessage: boolean
  locale: AppLocale
  message: string
  modifiedCount: number
  onClose: () => void
  onGenerateMessage?: () => Promise<string> | string
  onGeneratedMessage: (message: string) => void
  onSubmit: () => void
}) {
  return (
    <DialogFooter className="flex-row items-center justify-between sm:justify-between">
      <span className="text-[11px] text-muted-foreground">{shortcutHint}</span>
      <div className="flex gap-2">
        <CommitMessageGenerateButton
          isGeneratingMessage={isGeneratingMessage}
          locale={locale}
          modifiedCount={modifiedCount}
          onGenerateMessage={onGenerateMessage}
          onGeneratedMessage={onGeneratedMessage}
        />
        <Button variant="outline" onClick={onClose}>
          Cancel
        </Button>
        <Button onClick={onSubmit} disabled={!message.trim()}>
          {actionLabel}
        </Button>
      </div>
    </DialogFooter>
  )
}

interface CommitDialogProps {
  open: boolean
  modifiedCount: number
  authorIdentity?: GitAuthorIdentity | null
  commitMode?: CommitMode
  locale?: AppLocale
  repositories?: GitRepositoryOption[]
  selectedRepositoryPath?: string
  generatedMessage?: string
  generatedMessageKey?: number
  isGeneratingMessage?: boolean
  suggestedMessage?: string
  onGenerateMessage?: () => Promise<string> | string
  onRepositoryChange?: (path: string) => void
  onCommit: (message: string) => void
  onClose: () => void
}

export function CommitDialog(props: CommitDialogProps) {
  const {
    open,
    modifiedCount,
    authorIdentity = null,
    commitMode = 'push',
    locale = 'en',
    repositories = [],
    selectedRepositoryPath = '',
    generatedMessage,
    generatedMessageKey = 0,
    isGeneratingMessage = false,
    suggestedMessage,
    onGenerateMessage,
    onRepositoryChange,
    onCommit,
    onClose,
  } = props
  const [message, setMessage] = useState('')
  const inputRef = useRef<HTMLTextAreaElement>(null)
  const suggestedMessageRef = useRef(suggestedMessage)
  const copy = getDialogCopy(commitMode)

  useEffect(() => {
    suggestedMessageRef.current = suggestedMessage
  }, [suggestedMessage])

  useEffect(() => {
    if (open) {
      setMessage(suggestedMessageRef.current ?? '') // eslint-disable-line react-hooks/set-state-in-effect -- reset on dialog open
      focusMessageInput(inputRef)
    }
  }, [open])

  useGeneratedCommitMessage({ generatedMessage, generatedMessageKey, inputRef, open, setMessage })

  const handleSubmit = () => {
    const trimmed = message.trim()
    if (!trimmed) return
    onCommit(trimmed)
  }

  const handleKeyDown = (e: React.KeyboardEvent) => {
    if (isSubmitShortcut(e)) {
      e.preventDefault()
      handleSubmit()
    } else if (isCloseShortcut(e)) {
      onClose()
    }
  }

  const handleGeneratedMessage = (generated: string) => {
    setMessage(generated)
    focusMessageInput(inputRef)
  }

  return (
    <Dialog open={open} onOpenChange={(isOpen) => { if (!isOpen) onClose() }}>
      <DialogContent showCloseButton={false} className="sm:max-w-[420px]">
        <DialogHeader>
          <div className="flex items-center justify-between">
            <DialogTitle>{copy.title}</DialogTitle>
            <Badge variant="secondary" className="text-xs">
              {changedFilesLabel(modifiedCount)}
            </Badge>
          </div>
          <DialogDescription>{copy.description}</DialogDescription>
        </DialogHeader>
        {onRepositoryChange && selectedRepositoryPath && (
          <GitRepositorySelect
            label={translate(locale, 'git.repository.select')}
            repositories={repositories}
            selectedPath={selectedRepositoryPath}
            onChange={onRepositoryChange}
            testId="commit-repository-select"
          />
        )}
        <CommitAuthorIdentity identity={authorIdentity} locale={locale} />
        <Textarea
          ref={inputRef}
          className="min-h-[84px] resize-y bg-[var(--bg-input)] py-2.5 text-[13px]"
          placeholder="Commit message..."
          value={message}
          onChange={(e) => setMessage(e.target.value)}
          onKeyDown={handleKeyDown}
          rows={3}
        />
        <CommitDialogActions
          {...copy}
          isGeneratingMessage={isGeneratingMessage}
          locale={locale}
          message={message}
          modifiedCount={modifiedCount}
          onClose={onClose}
          onGenerateMessage={onGenerateMessage}
          onGeneratedMessage={handleGeneratedMessage}
          onSubmit={handleSubmit}
        />
      </DialogContent>
    </Dialog>
  )
}