import type { AxiosError } from 'axios';
import type { MutationApiOptions } from '../mutation.api';
import { MutationApi } from '../mutation.api';

/**
 * Factory for creating a MutationApi instance.
 * Accepts either a plain options object or a function.
 *
 * Use a **function** when options depend on observables (e.g., `invalidatedQueries` with dynamic keys) —
 * MobX tracks observables accessed during the function call and updates options on change.
 * A plain object is evaluated once at class field initialization and does not react to changes.
 *
 * @example Plain object (options don't depend on observables)
 * ```typescript
 * deleteJob = mutation<void, { id: number }>({
 *     mutationFn: async (arg) => await this.api?.deleteJob(arg.id),
 *     invalidatedQueries: [['scheduling', 'jobs']],
 * });
 * ```
 *
 * @example Function (options depend on observables — reactive)
 * ```typescript
 * updateJob = mutation<Job, UpdateJobRequest>(() => ({
 *     mutationFn: async (req) => (await this.api?.updateJob(req))?.data,
 *     invalidatedQueries: [['scheduling', 'jobs'], ['scheduling', 'job', this.selectedJobId]],
 * }));
 * ```
 */
export function mutation<TData = unknown, TVariables = void, TError = AxiosError>(
    options:
        | MutationApiOptions<TData, TVariables, TError>
        | (() => MutationApiOptions<TData, TVariables, TError>)
): MutationApi<TData, TVariables, TError> {
    const optionsFn = typeof options === 'function' ? options : () => options;
    return new MutationApi<TData, TVariables, TError>(optionsFn);
}