import {GeneratorOptions} from './index.js';
import {JSONSchema7} from 'json-schema';
import {ElasticsearchOptionsDSL} from '../dsl/schema.js';
import {
  IndicesPutTemplateRequest,
  MappingProperty,
  MappingTypeMapping,
  SearchRequest,
} from '@elastic/elasticsearch/lib/api/types.js';
import {Context} from './context.js';
import deepmerge from 'deepmerge';
import {renderTemplate} from '../template.js';

/**
 * Sanitize a type name
 */
export function sanitizeTypeName(typeName: string): string {
  return typeName.replaceAll(' ', '_');
}

export class MappingGenerator {
  readonly presets: Map<string, ElasticsearchOptionsDSL>;

  readonly cache: Map<string, {mapping: MappingProperty; dependencies: Map<string, Set<string>>}>;

  readonly searchMods: {mods: Partial<SearchRequest>} = {mods: {}};

  readonly template: Partial<IndicesPutTemplateRequest>;

  constructor(readonly project: JSONSchema7, options: GeneratorOptions) {
    this.template = options.template ?? {};
    this.presets = new Map(Object.entries(options.presets));
    this.cache = new Map(
      Object.entries(options.overrides).map(([name, mapping]) => [
        name,
        {
          mapping,
          dependencies: new Map(),
        },
      ]),
    );
  }

  buildTemplate(name: string): IndicesPutTemplateRequest {
    const thingType = ((this.project.definitions![name] as JSONSchema7).properties!.type as JSONSchema7)
      .const;
    if (typeof thingType !== 'string') {
      throw new TypeError(`${name} needs a valid thing type`);
    }
    const mappingContext = new Context(this, thingType, [name], [], new Map());
    const mappings = mappingContext.resolveReference(name);

    const request: IndicesPutTemplateRequest = deepmerge(
      {mappings: mappings as MappingTypeMapping},
      renderTemplate(this.template, [
        ['{name}', name],
        ['{type}', thingType],
        ['{_type}', sanitizeTypeName(thingType)],
      ]),
    );

    if (mappingContext.dependencies.size > 0) {
      request.mappings!.dynamic_templates = [];
      for (const [name, paths] of mappingContext.dependencies) {
        request.mappings!.dynamic_templates.push({
          [name]: {
            path_match: paths.size > 1 ? [...paths] : paths.values().next().value,
            mapping: mappingContext.resolveReference(name),
          },
        });
      }
    }

    return request;
  }
}