<?php
namespace taskman;
use Exception;

class ConfigScanResult implements \ArrayAccess, \Countable, \Iterator
{
  /*var array<string, string[]>*/
  public array $base_dir2files = array();

  private $iter_pos = 0;

  function __construct(array $base_dir2files = array())
  {
    foreach($base_dir2files as $dir => $files)
      $this->base_dir2files[$dir] = $files;
  }

  function clear()
  {
    $this->base_dir2files = array();
  }

  function isEmpty() : bool
  {
    return empty($this->base_dir2files);
  }

  function count() : int
  {
    $total = 0;
    foreach($this->base_dir2files as $base_dir => $files)
      $total += count($files);
    return $total;
  }

  function apply(callable $fn)
  {
    foreach($this->base_dir2files as $base_dir => $files)
      $this->base_dir2files[$base_dir] = $fn($base_dir, $files);
  }

  function filter(callable $filter)
  {
    foreach($this->base_dir2files as $base_dir => $files)
      $this->base_dir2files[$base_dir] = array_filter($files, $filter);
  }

  function forEachFile(callable $fn)
  {
    foreach($this->base_dir2files as $base_dir => $files)
    {
      foreach($files as $file)
        $fn($base_dir, $file);
    }
  }

  function add(string $base_dir, string $file)
  {
    if(!isset($this->base_dir2files[$base_dir]))
      $this->base_dir2files[$base_dir] = array();

    $this->base_dir2files[$base_dir][] = $file;
  }

  //returns [[base_dir, file1], [base_dir, file2], ...]
  function getFlatArray() : array
  {
    $flat = [];
    foreach($this->base_dir2files as $base_dir => $files)
    {
      foreach($files as $file)
        $flat[] = [$base_dir, $file];
    }
    return $flat;
  }

  function getAllFiles() : array
  {
    $all_files = [];
    foreach($this->base_dir2files as $base_dir => $files)
      $all_files = array_merge($all_files, $files);

    return $all_files;
  }
   
  //ArrayAccess interface
  function offsetExists(mixed $offset) : bool
  {
    if(!is_int($offset))
      throw new Exception("Invalid offset");

    return $this->count() > $offset;
  }

  function offsetGet(mixed $offset) : mixed
  {
    if(!is_int($offset))
      throw new Exception("Invalid offset");

    foreach($this->base_dir2files as $base_dir => $files)
    {
      $n = count($files);
      if($offset - $n < 0)
        return $files[$offset];
      $offset -= $n;
    }
    return null;
  }

  function offsetSet(mixed $offset, mixed $value) : void
  {
    if(!is_int($offset))
      throw new Exception("Invalid offset");

    foreach($this->base_dir2files as $base_dir => &$files)
    {
      $n = count($files);
      if($offset - $n < 0)
      {
        $files[$offset] = $value;
        return;
      }
      $offset -= $n;
    }
  }

  function offsetUnset(mixed $offset) : void
  {
    if(!is_int($offset))
      throw new Exception("Invalid offset");

    foreach($this->base_dir2files as $base_dir => $files)
    {
      $n = count($files);
      if($offset - $n < 0)
      {
        unset($files[$offset]);
        return;
      }
      $offset -= $n;
    }
  }

  //Iterator interface
  function rewind() : void
  {
    $this->iter_pos = 0;
  }

  function current() : mixed 
  {
    return $this->offsetGet($this->iter_pos);
  }

  function key() : mixed 
  {
    return $this->iter_pos;
  }

  function next() : void
  {
    ++$this->iter_pos;
  }

  function valid() : bool 
  {
    return $this->offsetExists($this->iter_pos);
  }
}

function config_scan_files(
  iterable $base_dirs, 
  string $ext_filter = '.conf.js', 
  bool $verbose = false
  ) : ConfigScanResult
{
  $t = microtime(true);

  $result = new ConfigScanResult();

  foreach($base_dirs as $base_dir)
  {
    $result->base_dir2files[$base_dir] = 
      scan_files_rec(array($base_dir), array($ext_filter));
  }

  if($verbose)
    config_log("File scan: {$result->count()}, done " . round(microtime(true) - $t,2) . " sec.");

  return $result;
}

function config_hash_changed(ConfigGlobals $globals, iterable $all_files)
{
  $all_crc_file = $globals->build_dir . "/configs.crc";
  return names_hash_changed($all_crc_file, $all_files);
}