import {z} from 'zod'

export type SystemMessage = {role: 'system', content: string | Array<{type: 'text', text: string}>, name?: string | undefined};

export type UserMessage = {role: 'user', content: string | Array<{type: 'text', text: string} | {type: 'image_url', image_url: {url: string}}>, name?: string | undefined};

export type AssistantMessage = {role: 'assistant', content?: (string | Array<{type: 'text', text: string}> | null) | undefined, name?: string | undefined, reasoning?: (string | null) | undefined, tool_calls?: Array<{id: string, type: 'function', function: {name: string, arguments: string}}> | undefined};

export type ToolMessage = {role: 'tool', content: string | Array<{type: 'text', text: string}>, tool_call_id: string};

export type DeveloperMessage = {role: 'developer', content: string | Array<{type: 'text', text: string}>, name?: string | undefined};

export type ResponseFormatText = {type: 'text'};

export type ResponseFormatJsonSchema = {type: 'json_schema', json_schema: {name: string, description?: string | undefined, schema?: Record<string, never> | undefined, strict?: boolean | undefined}};

export type ResponseFormatJsonObject = {type: 'json_object'};

export type ChatCompletionRequest = {messages: Array<SystemMessage | UserMessage | AssistantMessage | ToolMessage | DeveloperMessage>, model: string, clear_thinking?: (boolean | null) | undefined, frequency_penalty?: (number | null) | undefined, logit_bias?: ({[key: string]: number} | null) | undefined, logprobs?: boolean | undefined, max_completion_tokens?: (number | null) | undefined, parallel_tool_calls?: (boolean | null) | undefined, prediction?: ({type: 'content', content: string | Array<{type: 'text', text: string}>} | null) | undefined, presence_penalty?: (number | null) | undefined, prompt_cache_key?: (string | null) | undefined, reasoning_effort?: ('low' | 'medium' | 'high' | 'none' | null) | undefined, response_format?: (ResponseFormatText | ResponseFormatJsonSchema | ResponseFormatJsonObject | null) | undefined, seed?: (number | null) | undefined, service_tier?: ('priority' | 'default' | 'auto' | 'flex' | null) | undefined, stop?: (string | null) | undefined, stream?: (boolean | null) | undefined, temperature?: (number | null) | undefined, tool_choice?: ('none' | 'auto' | 'required' | {type: 'function', function: {name: string}}) | undefined, tools?: (Array<{type: 'function', function: {name: string, description?: string | undefined, parameters?: Record<string, never> | undefined}}> | null) | undefined, top_logprobs?: (number | null) | undefined, top_p?: (number | null) | undefined, user?: (string | null) | undefined};

export type CreateApiV1ChatCompletionsArgs = {'Content-Type'?: ('application/json' | 'application/vnd.msgpack') | undefined, 'Content-Encoding'?: 'gzip' | undefined, queue_threshold?: string | undefined, body: ChatCompletionRequest};

export type CreateApiV1ChatCompletionsOptions = {baseUrl?: string | undefined, BearerAuth?: string | undefined, fetch?: typeof fetch | undefined};

export const chatCompletionResponse = z.object({id: z.string().optional(), choices: z.array(z.object({finish_reason: z.enum(["stop", "length", "content_filter", "tool_calls"]).optional(), index: z.number().int().optional(), logprobs: z.object({}).nullable().optional(), reasoning_logprobs: z.object({}).nullable().optional(), message: z.object({content: z.string().nullable().optional(), role: z.string().optional(), reasoning: z.string().optional(), tool_calls: z.array(z.object({id: z.string().optional(), type: z.literal("function").optional(), function: z.object({name: z.string().optional(), arguments: z.string().optional()}).optional()})).nullable().optional()}).optional()})).optional(), created: z.number().int().optional(), model: z.string().optional(), object: z.literal("chat.completion").optional(), system_fingerprint: z.string().optional(), service_tier: z.string().nullable().optional(), service_tier_used: z.enum(["priority", "default", "flex"]).nullable().optional(), usage: z.object({prompt_tokens: z.number().int().optional(), completion_tokens: z.number().int().optional(), total_tokens: z.number().int().optional(), image_tokens: z.number().int().optional(), prompt_tokens_details: z.object({cached_tokens: z.number().int().optional()}).optional(), completion_tokens_details: z.object({accepted_prediction_tokens: z.number().int().optional(), rejected_prediction_tokens: z.number().int().optional(), reasoning_tokens: z.number().int().optional()}).optional()}).optional(), time_info: z.object({queue_time: z.number().optional(), prompt_time: z.number().optional(), completion_time: z.number().optional(), total_time: z.number().optional(), created: z.number().optional()}).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
};

/**
 * Create chat completion
 * 
 * POST /v1/chat/completions
 */
export const createApiV1ChatCompletions = async (args: CreateApiV1ChatCompletionsArgs, options?: CreateApiV1ChatCompletionsOptions) => {
const {baseUrl = "https://api.cerebras.ai", fetch: fetchFn = fetch, BearerAuth} = options ?? {}

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

if (args['Content-Type'] != null) headers.set("Content-Type", String(args['Content-Type']))
if (args['Content-Encoding'] != null) headers.set("Content-Encoding", String(args['Content-Encoding']))
if (args.queue_threshold != null) headers.set("queue_threshold", String(args.queue_threshold))
if (BearerAuth !== undefined) headers.set('authorization', `Bearer ${BearerAuth}`)

const url = `${baseUrl.replace(/\/+$/, '')}/v1/chat/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(chatCompletionResponse, await res.json())
};