import {z} from 'zod'

export type FIMCompletionRequest = {top_p?: number | undefined, random_seed?: (number | null) | undefined, stop?: (string | Array<string>) | undefined, max_tokens?: (number | null) | undefined, stream?: boolean | undefined, temperature?: (number | null) | undefined, model: string, suffix?: (string | null) | undefined, prompt: string, min_tokens?: (number | null) | undefined};

export type CreateApiFimCompletionsArgs = {body: FIMCompletionRequest};

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

export const usageInfo = z.object({completion_tokens: z.number().int(), prompt_tokens: z.number().int(), total_tokens: z.number().int()});

export const functionCall = z.object({name: z.string(), arguments: z.union([z.record(z.string(), z.unknown()), z.string()])});

export const toolTypes = z.literal("function");

export const toolCall = z.object({function: functionCall, index: z.number().int().optional(), id: z.string().optional(), type: toolTypes.optional()});

export const textChunk = z.object({text: z.string(), type: z.literal("text").optional()});

export const imageURLChunk = z.object({image_url: z.union([z.object({detail: z.string().nullable().optional(), url: z.string()}), z.string()]), type: z.literal("image_url").optional()});

export const documentURLChunk = z.object({document_name: z.string().nullable().optional(), type: z.string().optional(), document_url: z.string()});

export const referenceChunk = z.object({reference_ids: z.array(z.number().int()), type: z.literal("reference").optional()});

export const contentChunk = z.discriminatedUnion("type", [textChunk, imageURLChunk, documentURLChunk, referenceChunk]);

export const assistantMessage = z.object({role: z.literal("assistant").optional(), prefix: z.boolean().optional(), tool_calls: z.array(toolCall).nullable().optional(), content: z.union([z.string(), z.array(contentChunk)]).nullable().optional()});

export const chatCompletionChoice = z.object({finish_reason: z.enum(["stop", "length", "model_length", "error", "tool_calls"]), index: z.number().int(), message: assistantMessage});

export const fIMCompletionResponse = z.object({usage: usageInfo, model: z.string(), id: z.string(), object: z.string(), created: z.number().int().optional(), choices: z.array(chatCompletionChoice).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
};

/**
 * Fim Completion
 * 
 * POST /fim/completions
 */
export const createApiFimCompletions = async (args: CreateApiFimCompletionsArgs, options?: CreateApiFimCompletionsOptions) => {
const {baseUrl = "https://api.mistral.ai/v1", fetch: fetchFn = fetch, ApiKey} = options ?? {}

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

if (ApiKey !== undefined) headers.set('authorization', `Bearer ${ApiKey}`)

const url = `${baseUrl.replace(/\/+$/, '')}/fim/completions${query.size > 0 ? `?${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(fIMCompletionResponse, await res.json())
};