/**
 ******************************************************************************
 * Xenia : Xbox 360 Emulator Research Project                                 *
 ******************************************************************************
 * Copyright 2013 Ben Vanik. All rights reserved.                             *
 * Released under the BSD license - see LICENSE in the root for more details. *
 ******************************************************************************
 */

#include <xenia/kernel/fs/filesystem.h>

#include <xenia/kernel/fs/devices/disc_image_device.h>
#include <xenia/kernel/fs/devices/local_directory_device.h>


using namespace xe;
using namespace xe::kernel;
using namespace xe::kernel::fs;


FileSystem::FileSystem(xe_pal_ref pal) {
  pal_ = xe_pal_retain(pal);
}

FileSystem::~FileSystem() {
  // Delete all devices.
  // This will explode if anyone is still using data from them.
  for (std::vector<Device*>::iterator it = devices_.begin();
       it != devices_.end(); ++it) {
    delete *it;
  }
  devices_.clear();
  symlinks_.clear();

  xe_pal_release(pal_);
}

int FileSystem::RegisterDevice(const char* path, Device* device) {
  devices_.push_back(device);
  return 0;
}

int FileSystem::RegisterLocalDirectoryDevice(
    const char* path, const xechar_t* local_path) {
  Device* device = new LocalDirectoryDevice(pal_, path, local_path);
  return RegisterDevice(path, device);
}

int FileSystem::RegisterDiscImageDevice(
    const char* path, const xechar_t* local_path) {
  DiscImageDevice* device = new DiscImageDevice(pal_, path, local_path);
  if (device->Init()) {
    return 1;
  }
  return RegisterDevice(path, device);
}

int FileSystem::CreateSymbolicLink(const char* path, const char* target) {
  symlinks_.insert(std::pair<const char*, const char*>(
      xestrdupa(path),
      xestrdupa(target)));
  return 0;
}

int FileSystem::DeleteSymbolicLink(const char* path) {
  std::tr1::unordered_map<std::string, std::string>::iterator it =
      symlinks_.find(std::string(path));
  if (it != symlinks_.end()) {
    symlinks_.erase(it);
    return 0;
  }
  return 1;
}

Entry* FileSystem::ResolvePath(const char* path) {
  // Strip off prefix and pass to device.
  // e.g., d:\some\PATH.foo -> some\PATH.foo
  // Support both symlinks and device specifiers, like:
  // \\Device\Foo\some\PATH.foo, d:\some\PATH.foo, etc.

  // TODO(benvanik): normalize path/etc
  // e.g., remove ..'s and such

  // Resolve symlinks.
  // TODO(benvanik): more robust symlink handling - right now we assume simple
  //     drive path -> device mappings with nothing nested.
  char full_path[XE_MAX_PATH];
  XEIGNORE(xestrcpya(full_path, XECOUNT(full_path), path));
  for (std::tr1::unordered_map<std::string, std::string>::iterator it =
       symlinks_.begin(); it != symlinks_.end(); ++it) {
    if (xestrcasestra(path, it->first.c_str()) == path) {
      // Found symlink, fixup.
      const char* after_path = path + it->first.size();
      XEIGNORE(xesnprintfa(full_path, XECOUNT(full_path), "%s%s",
                           it->second.c_str(), after_path));
      break;
    }
  }

  // Scan all devices.
  for (std::vector<Device*>::iterator it = devices_.begin();
       it != devices_.end(); ++it) {
    Device* device = *it;
    if (xestrcasestra(full_path, device->path()) == full_path) {
      // Found!
      // Trim the device prefix off and pass down.
      char device_path[XE_MAX_PATH];
      XEIGNORE(xestrcpya(device_path, XECOUNT(device_path),
                         full_path + xestrlena(device->path())));
      return device->ResolvePath(device_path);
    }
  }

  XELOGE(XT("ResolvePath(%s) failed - no root found"), path);
  return NULL;
}