import {z} from 'zod'

export type ToolCall = {function?: ({name: string, description?: string | undefined, arguments?: Record<string, never> | undefined}) | undefined};

export type ChatMessage = {role: 'system' | 'user' | 'assistant' | 'tool', content: string, images?: Array<string> | undefined, tool_calls?: Array<ToolCall> | undefined};

export type ToolDefinition = {type: 'function', function: {name: string, description?: string | undefined, parameters: Record<string, never>}};

export type ModelOptions = {seed?: number | undefined, temperature?: number | undefined, top_k?: number | undefined, top_p?: number | undefined, min_p?: number | undefined, stop?: (string | Array<string>) | undefined, num_ctx?: number | undefined, num_predict?: number | undefined} | {[key: string]: unknown};

export type ChatRequest = {model: string, messages: Array<ChatMessage>, tools?: Array<ToolDefinition> | undefined, format?: ('json' | Record<string, never>) | undefined, options?: ModelOptions | undefined, stream?: boolean | undefined, think?: (boolean | 'high' | 'medium' | 'low' | 'max') | undefined, keep_alive?: (string | number) | undefined, logprobs?: boolean | undefined, top_logprobs?: number | undefined};

export type CreateApiApiChatArgs = {body: ChatRequest};

export type CreateApiApiChatOptions = {baseUrl?: string | undefined, fetch?: typeof fetch | undefined};

export const toolCall = z.object({function: z.object({name: z.string(), description: z.string().optional(), arguments: z.object({}).optional()}).optional()});

export const tokenLogprob = z.object({token: z.string().optional(), logprob: z.number().optional(), bytes: z.array(z.number().int()).optional()});

export const logprob = z.object({token: z.string().optional(), logprob: z.number().optional(), bytes: z.array(z.number().int()).optional(), top_logprobs: z.array(tokenLogprob).optional()});

export const chatResponse = z.object({model: z.string().optional(), created_at: z.string().optional(), message: z.object({role: z.literal("assistant").optional(), content: z.string().optional(), thinking: z.string().optional(), tool_calls: z.array(toolCall).optional(), images: z.array(z.string()).optional()}).optional(), done: z.boolean().optional(), done_reason: z.string().optional(), total_duration: z.number().int().optional(), load_duration: z.number().int().optional(), prompt_eval_count: z.number().int().optional(), prompt_eval_duration: z.number().int().optional(), eval_count: z.number().int().optional(), eval_duration: z.number().int().optional(), logprobs: z.array(logprob).optional()});

export const validateResponse = async <Output>(
  schema: {
    readonly '~standard': {
      readonly validate: (value: unknown) => ({ readonly value: Output; readonly issues?: undefined } | { readonly issues: ReadonlyArray<{ readonly message: string; readonly path?: ReadonlyArray<PropertyKey | { readonly key: PropertyKey }> | undefined }> }) | Promise<{ readonly value: Output; readonly issues?: undefined } | { readonly issues: ReadonlyArray<{ readonly message: string; readonly path?: ReadonlyArray<PropertyKey | { readonly key: PropertyKey }> | undefined }> }>
    }
  },
  value: unknown
): Promise<Output> => {
  const result = await schema['~standard'].validate(value)

  if (result.issues !== undefined) {
    const detail = result.issues
      .map(({ message, path }) =>
        path?.length
          ? `${path.map((segment) => String(typeof segment === 'object' ? segment.key : segment)).join('.')}: ${message}`
          : message
      )
      .join('; ')

    throw new Error(`Response does not match the schema: ${detail}`, { cause: { issues: result.issues } })
  }

  return result.value
};

/**
 * Generate a chat message
 * 
 * POST /api/chat
 */
export const createApiApiChat = async (args: CreateApiApiChatArgs, options?: CreateApiApiChatOptions) => {
const {baseUrl = "http://localhost:11434", fetch: fetchFn = fetch} = options ?? {}

const query = new URLSearchParams()
const headers = new Headers()
headers.set('content-type', "application/json")
headers.set('accept', "application/json")

const url = `${baseUrl.replace(/\/+$/, '')}/api/chat${query.size > 0 ? `?${query}` : ''}`

const res = await fetchFn(url, {method: "POST", headers, body: JSON.stringify(args.body)})

if (!res.ok) throw new Error(`Request failed with status ${res.status}`, {cause: {status: res.status, body: await res.text()}})

return validateResponse(chatResponse, await res.json())
};