import { useGeneration } from './use-generation'
import { reconstructImageResult } from '@tanstack/ai-client'
import type {
  UseGenerationOptions,
  UseGenerationReturn,
} from './use-generation'
import type { ImageGenerationResult, StreamChunk } from '@tanstack/ai'
import type {
  AIDevtoolsDisplayOptions,
  ConnectConnectionAdapter,
  GenerationClientState,
  GenerationFetcher,
  GenerationPersistenceOptions,
  ImageGenerateInput,
  InferGenerationOutputFromReturn,
} from '@tanstack/ai-client'
import type { Accessor } from 'solid-js'

/**
 * Options for the useGenerateImage hook.
 *
 * @template TOutput - The transformed output type (defaults to ImageGenerationResult)
 */
export interface UseGenerateImageOptions<
  TOutput = ImageGenerationResult,
> extends Pick<
  UseGenerationOptions<ImageGenerateInput, ImageGenerationResult, TOutput>,
  | 'persistence'
  | 'threadId'
  | 'hydrateGeneration'
  | 'joinRun'
  | 'byok'
  | 'byokProvider'
> {
  /** Connect-based adapter for streaming transport (SSE, HTTP stream, custom) */
  connection?: ConnectConnectionAdapter
  /** Direct async function for image generation */
  fetcher?: GenerationFetcher<ImageGenerateInput, ImageGenerationResult>
  /** Additional body parameters to send with connect-based adapter requests */
  body?: Record<string, any>
  /** Display options for TanStack AI Devtools. */
  devtools?: AIDevtoolsDisplayOptions
  /**
   * Callback when images are generated. Can optionally return a transformed value.
   *
   * - Return a non-null value to transform and store it as the result
   * - Return `null` to keep the previous result unchanged
   * - Return nothing (`void`) to store the raw result as-is
   */
  onResult?: (result: ImageGenerationResult) => TOutput | null | void
  /** Callback when an error occurs */
  onError?: (error: Error) => void
  /** Callback when progress is reported (0-100) */
  onProgress?: (progress: number, message?: string) => void
  /** Callback for each stream chunk (connect-based adapter mode only) */
  onChunk?: (chunk: StreamChunk) => void
}

/**
 * Return type for the useGenerateImage hook.
 *
 * @template TOutput - The transformed output type (defaults to ImageGenerationResult)
 */
export interface UseGenerateImageReturn<
  TOutput = ImageGenerationResult,
> extends Omit<UseGenerationReturn<TOutput>, 'generate'> {
  /** Trigger image generation */
  generate: (input: ImageGenerateInput) => Promise<void>
  /** The generation result containing images, or null */
  result: Accessor<TOutput | null>
  /** Whether generation is in progress */
  isLoading: Accessor<boolean>
  /** Current error, if any */
  error: Accessor<Error | undefined>
  /** Current state of the generation */
  status: Accessor<GenerationClientState>
}

/**
 * Solid hook for generating images using AI models.
 *
 * Supports two transport modes:
 * - **ConnectConnectionAdapter** -- Streaming transport (SSE, HTTP stream, custom)
 * - **Fetcher** -- Direct async function call
 *
 * @example
 * ```tsx
 * import { useGenerateImage } from '@tanstack/ai-solid'
 * import { fetchServerSentEvents } from '@tanstack/ai-client'
 *
 * function ImageGenerator() {
 *   const { generate, result, isLoading, error, reset } = useGenerateImage({
 *     connection: fetchServerSentEvents('/api/generate/image'),
 *   })
 *
 *   return (
 *     <div>
 *       <button onClick={() => generate({ prompt: 'A sunset over mountains' })}>
 *         Generate
 *       </button>
 *       {isLoading() && <p>Generating...</p>}
 *       {error() && <p>Error: {error()!.message}</p>}
 *       {result()?.images.map((img, i) => (
 *         <img src={img.url || `data:image/png;base64,${img.b64Json}`} />
 *       ))}
 *     </div>
 *   )
 * }
 * ```
 */
export function useGenerateImage<TTransformed = void>(
  options: Omit<
    UseGenerateImageOptions,
    'onResult' | 'persistence' | 'threadId'
  > & {
    onResult?: (result: ImageGenerationResult) => TTransformed
  } & GenerationPersistenceOptions,
): UseGenerateImageReturn<
  InferGenerationOutputFromReturn<ImageGenerationResult, TTransformed>
> {
  const devtools = {
    ...options.devtools,
    framework: 'solid',
    hookName: 'useGenerateImage',
    outputKind: 'image' as const,
  }
  const generation = useGeneration<
    ImageGenerateInput,
    ImageGenerationResult,
    TTransformed
  >({
    ...options,
    devtools,
    reconstructResult: reconstructImageResult,
  })

  return generation
}