import {z} from 'zod'

export type TaskState = 'new' | 'active' | 'retry' | 'expired' | 'terminated' | 'complete' | 'queue_error' | 'blocked' | 'unreachable';

export type GetApiV1TasksArgs = {state?: Array<TaskState> | undefined, queue?: string | undefined, type?: string | undefined, created_since?: string | undefined, limit?: number | undefined, stream?: 'ndjson' | undefined};

export type GetApiV1TasksOptions = {baseUrl: string, fetch?: typeof fetch | undefined};

export const taskResult = z.object({payload: z.unknown(), completed: z.string()});

export const taskState = z.enum(["new", "active", "retry", "expired", "terminated", "complete", "queue_error", "blocked", "unreachable"]);

export const task = z.object({id: z.string(), type: z.string(), queue: z.string().optional(), dependencies: z.array(z.string()).optional(), dependency_results: z.record(z.string(), taskResult).optional(), load_dependencies: z.boolean().optional(), payload: z.string(), deadline: z.string().optional(), max_tries: z.number().int().optional(), result: taskResult.optional(), state: taskState, created: z.string(), tried: z.string().optional(), tries: z.number().int().optional(), last_err: z.string().optional(), signature: z.string().optional()});

export const taskListResponse = z.object({tasks: z.array(task), count: z.number().int()});

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
};

/**
 * List tasks (snapshot).
 * 
 * GET /v1/tasks
 */
export const getApiV1Tasks = async (args: GetApiV1TasksArgs, options: GetApiV1TasksOptions) => {
const {baseUrl, fetch: fetchFn = fetch} = options ?? {}

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

for (const item of args.state ?? []) query.append("state", String(item))
if (args.queue != null) query.append("queue", String(args.queue))
if (args.type != null) query.append("type", String(args.type))
if (args.created_since != null) query.append("created_since", String(args.created_since))
if (args.limit != null) query.append("limit", String(args.limit))
if (args.stream != null) query.append("stream", String(args.stream))

const url = `${baseUrl.replace(/\/+$/, '')}/v1/tasks${query.size > 0 ? `?${query}` : ''}`

const res = await fetchFn(url, {method: "GET", headers})

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

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