import * as fs from "node:fs";
import * as cache from "@actions/cache";
import * as core from "@actions/core";
import * as exec from "@actions/exec";
import * as pep440 from "@renovatebot/pep440";
import {
  STATE_CACHE_KEY,
  STATE_CACHE_MATCHED_KEY,
} from "./cache/restore-cache";
import { STATE_UV_PATH, STATE_UV_VERSION } from "./utils/constants";
import {
  cacheLocalPath,
  cachePython,
  enableCache,
  ignoreNothingToCache,
  pythonDir,
  pruneCache as shouldPruneCache,
  saveCache as shouldSaveCache,
} from "./utils/inputs";

export async function run(): Promise<void> {
  try {
    if (enableCache) {
      if (shouldSaveCache) {
        await saveCache();
      } else {
        core.info("save-cache is false. Skipping save cache step.");
      }
      // node will stay alive if any promises are not resolved,
      // which is a possibility if HTTP requests are dangling
      // due to retries or timeouts. We know that if we got here
      // that all promises that we care about have successfully
      // resolved, so simply exit with success.
      process.exit(0);
    }
  } catch (error) {
    const err = error as Error;
    core.setFailed(err.message);
  }
}

async function saveCache(): Promise<void> {
  const cacheKey = core.getState(STATE_CACHE_KEY);
  const matchedKey = core.getState(STATE_CACHE_MATCHED_KEY);

  if (!cacheKey) {
    core.warning("Error retrieving cache key from state.");
    return;
  }
  if (matchedKey === cacheKey) {
    core.info(`Cache hit occurred on key ${cacheKey}, not saving cache.`);
    return;
  }

  if (shouldPruneCache) {
    await pruneCache();
  }

  let actualCachePath = cacheLocalPath;
  if (process.env.UV_CACHE_DIR && process.env.UV_CACHE_DIR !== cacheLocalPath) {
    core.warning(
      `The environment variable UV_CACHE_DIR has been changed to "${process.env.UV_CACHE_DIR}", by an action or step running after astral-sh/setup-uv. This can lead to unexpected behavior. If you expected this to happen set the cache-local-path input to "${process.env.UV_CACHE_DIR}" instead of "${cacheLocalPath}".`,
    );
    actualCachePath = process.env.UV_CACHE_DIR;
  }

  core.info(`Saving cache path: ${actualCachePath}`);
  if (!fs.existsSync(actualCachePath) && !ignoreNothingToCache) {
    throw new Error(
      `Cache path ${actualCachePath} does not exist on disk. This likely indicates that there are no dependencies to cache. Consider disabling the cache input if it is not needed.`,
    );
  }

  const cachePaths = [actualCachePath];
  if (cachePython) {
    core.info(`Including Python cache path: ${pythonDir}`);
    if (!fs.existsSync(pythonDir) && !ignoreNothingToCache) {
      throw new Error(
        `Python cache path ${pythonDir} does not exist on disk. This likely indicates that there are no dependencies to cache. Consider disabling the cache input if it is not needed.`,
      );
    }
    cachePaths.push(pythonDir);
  }

  core.info(`Final cache paths: ${cachePaths.join(", ")}`);
  try {
    await cache.saveCache(cachePaths, cacheKey);
    core.info(`cache saved with the key: ${cacheKey}`);
  } catch (e) {
    if (
      e instanceof Error &&
      e.message ===
        "Path Validation Error: Path(s) specified in the action for caching do(es) not exist, hence no cache is being saved."
    ) {
      core.info(
        "No cacheable paths were found. Ignoring because ignore-nothing-to-save is enabled.",
      );
    } else {
      throw e;
    }
  }
}

async function pruneCache(): Promise<void> {
  const forceSupported = pep440.gte(core.getState(STATE_UV_VERSION), "0.8.24");

  const options: exec.ExecOptions = {
    silent: false,
  };
  const execArgs = ["cache", "prune", "--ci"];
  if (forceSupported) {
    execArgs.push("--force");
  }

  core.info("Pruning cache...");
  const uvPath = core.getState(STATE_UV_PATH);
  await exec.exec(uvPath, execArgs, options);
}

run();