import {z} from 'zod'

export type ParseRequest = {lines: Array<string>, service?: (string | null) | undefined, source?: (string | null) | undefined};

export type CreateApiV1ParseArgs = {body: ParseRequest};

export type CreateApiV1ParseOptions = {baseUrl: string, fetch?: typeof fetch | undefined};

export const templateOut = z.object({template_id: z.string(), raw_template: z.string()});

export const parsedLineOut = z.object({line: z.string(), template_id: z.string().nullable().optional(), raw_template: z.string().nullable().optional(), cache_hit: z.boolean().optional()});

export const parseStats = z.object({llm_calls: z.number().int(), cache_hits: z.number().int(), unmatched: z.number().int(), elapsed_ms: z.number().int(), incident_family_hits: z.number().int().optional(), incident_induced_templates: z.number().int().optional(), global_cache_hits: z.number().int().optional(), global_shadow_hits: z.number().int().optional(), global_shadow_agreements: z.number().int().optional(), global_shadow_disagreements: z.number().int().optional(), total_patterns: z.number().int().optional(), candidate_patterns: z.number().int().optional(), dropped_patterns: z.number().int().optional(), cache_pattern_hits: z.number().int().optional(), global_cache_pattern_hits: z.number().int().optional()});

export const parseResponse = z.object({templates: z.array(templateOut), parsed: z.array(parsedLineOut), stats: parseStats});

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
};

/**
 * Parse Endpoint
 * 
 * POST /v1/parse
 */
export const createApiV1Parse = async (args: CreateApiV1ParseArgs, options: CreateApiV1ParseOptions) => {
const {baseUrl, 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 = `${baseUrl.replace(/\/+$/, '')}/v1/parse${query.size > 0 ? `?${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(parseResponse, await res.json())
};