import { z } from "zod";

const envSchema = z.object({
  OLLAMA_BASE_URL: z.string().url(),
  OLLAMA_MODEL: z.string().min(1),
});

const openAIExperimentEnvSchema = z.object({
  OPENAI_API_KEY: z.string().min(1),
});

export const OPENAI_UI_JOURNEY_EXPERIMENT_PROVIDER = "openai";
export const OPENAI_TERRA_MODEL = "gpt-5.6-terra";

export function isOpenAIUiJourneyExperiment() {
  return process.env.CONFIDENCE_ENGINE_EXPERIMENT_PROVIDER === OPENAI_UI_JOURNEY_EXPERIMENT_PROVIDER;
}

export function getConfig() {
  if (isOpenAIUiJourneyExperiment()) {
    const parsed = openAIExperimentEnvSchema.safeParse({
      OPENAI_API_KEY: process.env.OPENAI_API_KEY,
    });
    if (!parsed.success) return { ok: false, error: parsed.error.flatten().fieldErrors };
    return {
      ok: true,
      config: { provider: OPENAI_UI_JOURNEY_EXPERIMENT_PROVIDER, modelName: OPENAI_TERRA_MODEL },
    };
  }

  const parsed = envSchema.safeParse({
    OLLAMA_BASE_URL: process.env.OLLAMA_BASE_URL,
    OLLAMA_MODEL: process.env.OLLAMA_MODEL,
  });

  if (!parsed.success) {
    return { ok: false, error: parsed.error.flatten().fieldErrors };
  }

  return { ok: true, config: { ...parsed.data, provider: "ollama", modelName: parsed.data.OLLAMA_MODEL } };
}

export function assertConfig() {
  const result = getConfig();
  if (!result.ok) {
    throw new Error(
      "Invalid configuration:\n" +
        Object.entries(result.error).map(([k, v]) => `  ${k}: ${v}`).join("\n")
    );
  }
  return result.config;
}