import { existsSync, mkdirSync } from "fs";
import { readFile, writeFile } from "fs/promises";
import { dirname } from "path";
import type { RoutstrdConfig } from "../utils/config";
import type { IntegrationConfig, RoutstrModel } from "./registry";
import { callDaemon, getDaemonBaseUrl } from "../utils/daemon-client";

type PiModelEntry = {
  id: string;
  contextWindow?: number;
  // Preserve arbitrary manual fields (reasoning, thinkingLevelMap, compat, cost, maxTokens, etc.)
  [key: string]: unknown;
};

type PiProviderConfig = {
  baseUrl?: string;
  api?: string;
  apiKey?: string;
  models?: PiModelEntry[];
};

type PiConfig = {
  providers?: Record<string, PiProviderConfig>;
};

export async function installPiIntegration(
  config: RoutstrdConfig,
  apiKey: string,
  integrationConfig: IntegrationConfig,
): Promise<void> {
  const { name, configPath } = integrationConfig;

  console.log("\nInstalling routstr models in pi models.json...");
  console.log(`Using API key for ${name}`);

  const baseUrl = `${getDaemonBaseUrl(config)}/v1`;

  let piConfig: PiConfig = {};

  try {
    if (existsSync(configPath)) {
      const content = await readFile(configPath, "utf-8");
      piConfig = JSON.parse(content) as PiConfig;
    }
  } catch (error) {
    console.error(`Failed to read or parse ${configPath}; leaving it unchanged:`, error);
    return;
  }

  if (!piConfig.providers) {
    piConfig.providers = {};
  }

  try {
    // Ensure directory exists
    mkdirSync(dirname(configPath), { recursive: true });

    const data = await callDaemon("/models");
    const models = (data.output as { models: RoutstrModel[] } | undefined)?.models || [];

    if (models.length === 0) {
      console.log("No models found from routstr daemon.");
      return;
    }

    // Preserve any manually-added per-model fields (reasoning, thinkingLevelMap,
    // compat, cost, maxTokens, etc.) across refreshes. Only `id` and `contextWindow`
    // are managed by routstrd.
    const existingModels = new Map<string, PiModelEntry>(
      (piConfig.providers["routstr"]?.models ?? []).map((m) => [m.id, m]),
    );

    const providerModels: PiModelEntry[] = models.map((model) => {
      const previous = existingModels.get(model.id);
      const entry: PiModelEntry = previous ? { ...previous } : { id: model.id };

      entry.id = model.id;
      if (model.context_length !== undefined && model.context_length > 0) {
        entry.contextWindow = model.context_length;
      }

      return entry;
    });

    // Preserve provider-level manual fields (compat, headers, name, etc.); only update
    // the routstrd-managed fields below.
    piConfig.providers["routstr"] = {
      ...(piConfig.providers["routstr"] ?? {}),
      baseUrl,
      api: "openai-completions",
      apiKey,
      models: providerModels,
    };

    await writeFile(configPath, JSON.stringify(piConfig, null, 2));
    console.log(`Added "routstr" provider with ${models.length} models to pi models.json`);
  } catch (error) {
    console.error("Failed to install models in pi models.json:", error);
  }
}