import { useBreakpoint } from 'common'
import { AnimatePresence, motion } from 'framer-motion'
import { ArrowUp, Loader2, Square } from 'lucide-react'
import { ChangeEvent, FormEvent, forwardRef, KeyboardEvent, memo, ReactNode, useRef } from 'react'
import { Button, cn, ExpandingTextArea } from 'ui'

import { ButtonTooltip } from '../ButtonTooltip'
import { formatAttachedSnippets } from './AIAssistant.utils'
import { ModelSelector } from './ModelSelector'
import { SnippetRow } from './SnippetRow'
import type { AssistantModelId } from '@/lib/ai/model.utils'
import { type SqlSnippet } from '@/state/ai-assistant-state'

export interface FormProps {
  /* The ref for the textarea, optional. Exposed for the CommandsPopover to attach events. */
  textAreaRef?: React.RefObject<HTMLTextAreaElement | null>
  /* The loading state of the form */
  loading: boolean
  /* The disabled state of the form */
  disabled?: boolean
  /* The value of the textarea */
  value?: string
  /* The function to handle the value change */
  onValueChange: (value: ChangeEvent<HTMLTextAreaElement>) => void
  /**
   * If true, include SQL snippets in the message sent to onSubmit
   */
  includeSnippetsInMessage?: boolean
  /**
   * The function to handle the form submission
   */
  onSubmit: (message: string) => void
  /**
   * The function to handle stopping the stream
   */
  onStop?: () => void
  /* The placeholder of the textarea */
  placeholder?: string
  /* SQL snippets to display above the form - can be strings or objects with label and content */
  sqlSnippets?: SqlSnippet[]
  /* Function to handle removing a SQL snippet */
  onRemoveSnippet?: (index: number) => void
  /* Additional class name for the snippets container */
  snippetsClassName?: string
  /* Additional class name for the form wrapper */
  className?: string
  /* If currently editing an existing message */
  isEditing?: boolean
  /* The currently selected AI model */
  selectedModel?: AssistantModelId
  /* Callback when a model is chosen */
  onSelectModel?: (model: AssistantModelId) => void
  /* Icon for the submit button when not loading, defaults to an up arrow */
  submitIcon?: ReactNode
  /* Label for the submit button when not loading, used for both aria-label and tooltip text, defaults to "Send message" */
  submitLabel?: string
  /**
   * An additional action shown beside the main submit button, transitioned in/out with
   * framer-motion. Pass undefined to hide it (e.g. when the input doesn't match its condition).
   */
  secondaryAction?: {
    label: string
    onClick: () => void
  }
}

const AssistantChatFormComponent = forwardRef<HTMLFormElement, FormProps>(
  (
    {
      loading = false,
      disabled = false,
      value = '',
      textAreaRef,
      onValueChange,
      onSubmit,
      onStop,
      placeholder,
      sqlSnippets,
      onRemoveSnippet,
      snippetsClassName,
      includeSnippetsInMessage = false,
      className,
      isEditing = false,
      selectedModel,
      onSelectModel,
      submitIcon = <ArrowUp />,
      submitLabel = 'Send message',
      secondaryAction,
      ...props
    },
    _ref
  ) => {
    const formRef = useRef<HTMLFormElement>(null)
    const isMobile = useBreakpoint('md')

    const handleSubmit = (event?: FormEvent<HTMLFormElement>) => {
      if (event) event.preventDefault()
      if (disabled || !value || (loading && !isEditing)) return

      let finalMessage = value
      if (includeSnippetsInMessage && sqlSnippets && sqlSnippets.length > 0) {
        finalMessage = [value, formatAttachedSnippets(sqlSnippets)].filter(Boolean).join('\n\n')
      }

      onSubmit(finalMessage)
    }

    const handleKeyDown = (event: KeyboardEvent<HTMLTextAreaElement>) => {
      if (event.key === 'Enter' && !event.shiftKey) {
        event.preventDefault()
        handleSubmit()
      } else if (event.key === 'Escape') {
        event.currentTarget.blur()
      }
    }

    const canSubmit = !disabled && !loading && !!value
    const showModelSelector = selectedModel !== undefined && onSelectModel !== undefined

    return (
      <div className="w-full">
        <form
          id="assistant-chat"
          ref={formRef}
          {...props}
          onSubmit={handleSubmit}
          className={cn('relative rounded-lg', className)}
        >
          {sqlSnippets && sqlSnippets.length > 0 && (
            <SnippetRow
              snippets={sqlSnippets}
              onRemoveSnippet={onRemoveSnippet}
              className="absolute top-0 left-0 right-0 px-1.5 py-1.5"
            />
          )}
          <ExpandingTextArea
            autoFocus={!isMobile}
            ref={textAreaRef}
            disabled={disabled}
            className={cn(
              'text-base md:text-sm pr-10 pb-9 max-h-64 rounded-lg',
              sqlSnippets && sqlSnippets.length > 0 && 'pt-10'
            )}
            placeholder={placeholder}
            spellCheck={false}
            rows={3}
            value={value}
            onChange={(event) => onValueChange(event)}
            onKeyDown={handleKeyDown}
          />
          <div
            className={cn(
              'absolute inset-x-2 bottom-2 flex items-center pointer-events-none',
              showModelSelector ? 'justify-between' : 'justify-end'
            )}
          >
            {showModelSelector && (
              <div className="pointer-events-auto">
                <ModelSelector selectedModel={selectedModel} onSelectModel={onSelectModel} />
              </div>
            )}

            <div className="flex gap-x-1.5 items-center pointer-events-auto">
              <AnimatePresence>
                {!loading && secondaryAction && (
                  <motion.div
                    key="secondary-action"
                    initial={{ opacity: 0, scale: 0.8 }}
                    animate={{ opacity: 1, scale: 1 }}
                    exit={{ opacity: 0, scale: 0.8 }}
                    transition={{ duration: 0.15 }}
                  >
                    <Button
                      type="button"
                      variant="outline"
                      aria-label={secondaryAction.label}
                      onClick={secondaryAction.onClick}
                      className="h-7 rounded-full"
                    >
                      {secondaryAction.label}
                    </Button>
                  </motion.div>
                )}
              </AnimatePresence>
              {loading ? (
                onStop ? (
                  <ButtonTooltip
                    variant="outline"
                    aria-label="Stop response"
                    icon={<Square fill="currentColor" className="scale-75" />}
                    onClick={onStop}
                    className="w-7 h-7 rounded-full p-0 text-center flex items-center justify-center"
                    tooltip={{ content: { side: 'top', text: 'Stop response' } }}
                  />
                ) : (
                  <Loader2 size={22} className="animate-spin size-7 text-muted" strokeWidth={1} />
                )
              ) : (
                <ButtonTooltip
                  type="submit"
                  variant={canSubmit ? 'primary' : 'default'}
                  aria-label={submitLabel}
                  icon={submitIcon}
                  disabled={!canSubmit}
                  className={cn(
                    'w-7 h-7 rounded-full p-0 text-center flex items-center justify-center',
                    !canSubmit ? 'opacity-50' : 'opacity-100'
                  )}
                  tooltip={{ content: { side: 'top', text: submitLabel } }}
                />
              )}
            </div>
          </div>
        </form>
      </div>
    )
  }
)

AssistantChatFormComponent.displayName = 'AssistantChatFormComponent'

export const AssistantChatForm = memo(AssistantChatFormComponent)