import type {
  ExtractedFact,
  FactExtractor,
  LlmFactExtractorOptions,
} from "./types";

const DEFAULT_INSTRUCTIONS = [
  "Extract one structured fact from the user input.",
  "Return JSON only. Do not include markdown, explanations, or prose outside the JSON object.",
  'Use this shape: {"statement": string?, "summary": string|null, "source": string|null, "confidence": number|null, "metadata": object|null, "topics": Array<{"name": string, "category": "entity"|"concept"|"temporal"|"custom"?, "granularity": "abstract"|"concrete"|"mixed"?, "role": string|null, "description": string|null, "metadata": object|null}>}.',
  'Only include topics that are explicitly in the input as-is. For example, topic "I started TypeScript since 2015" can be "I", "TypeScript", "2015".',
].join("\n");

export class LlmFactExtractor implements FactExtractor {
  constructor(private readonly options: LlmFactExtractorOptions) {}

  async extract(input: string): Promise<ExtractedFact> {
    return this.options.model.generateText({
      instruction: DEFAULT_INSTRUCTIONS,
      input,
      additionalInstruction: this.options.additionalInstructions,
    });
  }
}