import { checkCache, updateCache } from "./cache.js";
import {
  createTrackedObject,
  fileExists,
  readFilesByGlob,
  removeBasePaths,
  removeCwd,
  replaceFileExtension,
  getValueAtPath
} from "./util/index.js";
import path from "path";
import process from "node:process";
import { getLogger } from "./logging.js";

export async function getConfig() {
  const args = process.argv.slice(2);
  const defaultPath = path.join(process.cwd(), "rhedyn.config.js");

  const findConfigPath = (args, index = 0) => {
    if (index >= args.length) {
      return defaultPath;
    }
    if (
      (args[index] === "-c" || args[index] === "--config") &&
      index + 1 < args.length
    ) {
      return path.resolve(args[index + 1]);
    }
    return findConfigPath(args, index + 1);
  };

  const configPath = findConfigPath(args);
  const configFileExists = await fileExists(configPath);

  if (configFileExists) {
    try {
      const config = await import(configPath);
      return config.default || config;
    } catch (err) {
      console.error(`Error reading config file at ${configPath}:`, err);
      throw new Error("Failed reading config file");
    }
  } else {
    return;
  }
}

async function runTask({ meta, config, jobId }) {
  const log = getLogger(
    config.logLevel ? config.logLevel : meta.opts.logLevel,
    jobId
  );
  log.trace(`meta: ${JSON.stringify(meta, null, 2)}`);
  log.trace(`config: ${JSON.stringify(config, null, 2)}`);

  const stateObject = {
    meta,
    config
  };
  const cache =
    meta.opts.cacheDir && !config.skipCache
      ? await checkCache(jobId, stateObject, meta.opts)
      : { disabled: true, reason: "Cache disabled" };

  if (cache && cache.hit) {
    log.debug(`Loaded cache for ${jobId}: ${cache.filePath}`);
    return { ...cache.taskResult, fromCache: true };
  }
  log.debug(`Cache miss for ${jobId} (${cache.reason})`);

  const state = meta.opts.cacheDir
    ? createTrackedObject(stateObject)
    : { proxy: stateObject };

  const {
    detail = {},
    paths = [],
    deps: processorDeps,
    ref
  } = await config.processor(state.proxy);

  const taskResult = {
    detail,
    paths: paths.map(fileOutputPath =>
      fileOutputPath.replace(meta.opts.outDir, "")
    ),
    ref
  };
  log.debug(`Wrote ${taskResult.paths.length} files for ${jobId}`);
  if (cache && !cache.disabled) {
    log.debug(`Updating cache for ${jobId}: ${cache.filePath}`);
    const processorPathDeps = processorDeps?.paths || [];
    const processorStateDeps = processorDeps?.state || [];
    const configPathDeps = config.deps?.paths || [];
    const configStateDeps = config.deps?.state || [];
    const stateSelectors = config.stateSelectors || [];
    await updateCache(
      meta.opts.cacheDir,
      jobId,
      removeCwd(
        [...configPathDeps, ...processorPathDeps, config?.filePath].filter(
          item => !!item
        )
      ),
      [
        ...configStateDeps,
        ...stateSelectors,
        ...processorStateDeps,
        ...(state?.accessed || [])
      ].filter(item => !!item),
      taskResult,
      cache.updates,
      meta.opts.includeStateValues
    );
  }

  return taskResult;
}

async function expandFileTask(patternsToInclude, config, meta) {
  const filesToProcess = await readFilesByGlob(patternsToInclude);
  const pathsToStrip = config.stripPaths || [];
  const outputDir = config.outputDir || "";
  return await Promise.all(
    filesToProcess.map(async filePath => {
      const fileOutputPath = path.join(
        meta.opts.outDir,
        outputDir,
        replaceFileExtension(
          removeBasePaths(pathsToStrip, filePath),
          config.outputFileExtension
        )
      );

      const fileOutputDir = path.dirname(fileOutputPath);
      const jobConfig = {
        ...config,
        filePath,
        fileOutputDir,
        fileOutputPath
      };
      return runTask({
        meta,
        config: jobConfig,
        jobId: `${config.name} @ ${filePath}`
      });
    })
  );
}

async function expandStateTask(stateToExpand, config, meta) {
  const stateToProcess = stateToExpand
    .map(property => {
      const values = getValueAtPath(meta, property);
      const expandedValues = Array.isArray(values)
        ? values
        : Object.values(values);
      return expandedValues.map((value, index) => ({ property, index, value }));
    })
    .flat();

  return await Promise.all(
    stateToProcess.map(async stateJob => {
      const jobConfig = {
        ...config,
        ...stateJob.value.detail
      };
      return runTask({
        meta,
        config: jobConfig,
        jobId: `${config.name} @ ${stateJob.property}:${stateJob.index}`
      });
    })
  );
}

export async function expandAndRunTask(meta, config) {
  const includes = meta.opts?.include?.[config.name] || [];
  const patternsToInclude = [...(config?.inputFiles || []), ...includes];

  if (patternsToInclude.length) {
    return expandFileTask(patternsToInclude, config, meta);
  }

  if (config.stateSelectors) {
    return expandStateTask(config.stateSelectors, config, meta);
  }

  const jobId = config.jobId || config.name;
  const taskResult = await runTask({ meta, config, jobId });
  return [taskResult];
}

export async function processTask(meta, task) {
  const log = getLogger(meta.opts.logLevel, task.name);
  const startTime = performance.now();
  const taskResult = await expandAndRunTask(meta, task);
  const cached = taskResult.filter(taskResult => taskResult.fromCache);
  const processed = taskResult.filter(taskResult => !taskResult.fromCache);
  const resources = taskResult.reduce(
    (obj, tResult) => (tResult.ref ? { ...obj, [tResult.ref]: tResult } : obj),
    {}
  );
  const endTime = performance.now();
  const timeTaken = endTime - startTime;
  const hrTime =
    timeTaken > 1000
      ? `${Number.parseFloat(timeTaken / 1000).toFixed(2)}s`
      : `${Number.parseFloat(timeTaken).toFixed(2)}ms`;
  const filesWritten = processed.reduce(
    (acc, cur) => acc + cur.paths.length,
    0
  );
  log.info(
    `written: ${filesWritten} | processed: ${processed.length} | from cache: ${
      cached.length
    } | ${hrTime}`
  );
  return {
    name: task.name,
    taskResult,
    cached,
    processed,
    resources,
    filesWritten
  };
}