import { PartitionKey } from "./keys"
import { Model } from "./Model"
import { ExtractFields } from "./types"

export class Partition<T extends Model<any, any, any>, U extends Model<any, any, any>> {
  private modelTags: string[]

  constructor(private models: [T, ...U[]]) {
    this.modelTags = models.map((_) => _.modelTag)
  }

  /** Since we assume that all this.models[] live under the same partition
   *  we can generate a valid partition key by calling models[0].partitionKey
   * (or any models[i].key - but models[0] is convenient)
   */
  key(params: Parameters<T["partitionKey"]>[0]): PartitionKey<ExtractFields<T | U>> {
    const { partitionKeyName, partitionKey } = this.models[0].partitionKey(params)
    return new PartitionKey<ExtractFields<T | U>>(partitionKeyName, partitionKey, this.modelTags)
  }
}