import {z} from 'zod'

export type UsageOwnerKind = 'document' | 'agent_run' | 'question' | 'knowledge_base' | 'knowledge_graph' | 'schematic' | 'experiment' | 'unattributed';

export type GetApiApiV0UsageArgs = {start?: (string | null) | undefined, end?: (string | null) | undefined, owner_kind?: (UsageOwnerKind | null) | undefined};

export type GetApiApiV0UsageOptions = {baseUrl: string, HTTPBearer?: string | undefined, fetch?: typeof fetch | undefined};

export const modelTokenUsageItem = z.object({model: z.string(), provider: z.string(), input_tokens: z.number().int(), cached_input_tokens: z.number().int().optional(), output_tokens: z.number().int(), estimated_cost_usd: z.number(), num_calls: z.number().int(), duration_ms: z.number().int()});

export const stepTokenUsageItem = z.object({task_type: z.string(), step: z.string(), input_tokens: z.number().int(), cached_input_tokens: z.number().int().optional(), output_tokens: z.number().int(), estimated_cost_usd: z.number(), num_calls: z.number().int(), duration_ms: z.number().int()});

export const ownerUsageItem = z.object({owner_kind: z.string(), input_tokens: z.number().int(), cached_input_tokens: z.number().int().optional(), output_tokens: z.number().int(), estimated_cost_usd: z.number(), num_calls: z.number().int(), duration_ms: z.number().int()});

export const usageResponse = z.object({total_input_tokens: z.number().int(), total_cached_input_tokens: z.number().int().optional(), total_output_tokens: z.number().int(), total_estimated_cost_usd: z.number(), total_duration_ms: z.number().int(), total_llm_calls: z.number().int(), model_usage: z.array(modelTokenUsageItem), step_usage: z.array(stepTokenUsageItem), owner_usage: z.array(ownerUsageItem)});

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
};

/**
 * Get LLM usage and estimated cost
 * 
 * GET /api/v0/usage
 */
export const getApiApiV0Usage = async (args: GetApiApiV0UsageArgs, options: GetApiApiV0UsageOptions) => {
const {baseUrl, fetch: fetchFn = fetch, HTTPBearer} = options ?? {}

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

if (args.start != null) query.append("start", String(args.start))
if (args.end != null) query.append("end", String(args.end))
if (args.owner_kind != null) query.append("owner_kind", String(args.owner_kind))
if (HTTPBearer !== undefined) headers.set('authorization', `Bearer ${HTTPBearer}`)

const url = `${baseUrl.replace(/\/+$/, '')}/api/v0/usage${query.size > 0 ? `?${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(usageResponse, await res.json())
};