// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "chrome/browser/upload_list.h"

#include <algorithm>
#include <iterator>

#include "base/bind.h"
#include "base/file_util.h"
#include "base/strings/string_number_conversions.h"
#include "base/strings/string_split.h"
#include "content/public/browser/browser_thread.h"

using content::BrowserThread;

UploadList::UploadInfo::UploadInfo(const std::string& c, const base::Time& t)
    : id(c), time(t) {}

UploadList::UploadInfo::~UploadInfo() {}

UploadList::UploadList(Delegate* delegate,
                       const base::FilePath& upload_log_path)
    : delegate_(delegate),
      upload_log_path_(upload_log_path) {}

UploadList::~UploadList() {}

void UploadList::LoadUploadListAsynchronously() {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  BrowserThread::PostBlockingPoolTask(
      FROM_HERE,
      base::Bind(&UploadList::LoadUploadListAndInformDelegateOfCompletion,
                 this));
}

void UploadList::ClearDelegate() {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  delegate_ = NULL;
}

void UploadList::LoadUploadListAndInformDelegateOfCompletion() {
  LoadUploadList();
  BrowserThread::PostTask(
      BrowserThread::UI,
      FROM_HERE,
      base::Bind(&UploadList::InformDelegateOfCompletion, this));
}

void UploadList::LoadUploadList() {
  if (base::PathExists(upload_log_path_)) {
    std::string contents;
    base::ReadFileToString(upload_log_path_, &contents);
    std::vector<std::string> log_entries;
    base::SplitStringAlongWhitespace(contents, &log_entries);
    ClearUploads();
    ParseLogEntries(log_entries);
  }
}

void UploadList::AppendUploadInfo(const UploadInfo& info) {
  uploads_.push_back(info);
}

void UploadList::ClearUploads() {
  uploads_.clear();
}

void UploadList::ParseLogEntries(
    const std::vector<std::string>& log_entries) {
  std::vector<std::string>::const_reverse_iterator i;
  for (i = log_entries.rbegin(); i != log_entries.rend(); ++i) {
    std::vector<std::string> components;
    base::SplitString(*i, ',', &components);
    // Skip any blank (or corrupted) lines.
    if (components.size() != 2)
      continue;
    double seconds_since_epoch;
    if (!base::StringToDouble(components[0], &seconds_since_epoch))
      continue;
    UploadInfo info(components[1],
                    base::Time::FromDoubleT(seconds_since_epoch));
    uploads_.push_back(info);
  }
}

void UploadList::InformDelegateOfCompletion() {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  if (delegate_)
    delegate_->OnUploadListAvailable();
}

void UploadList::GetUploads(unsigned int max_count,
                            std::vector<UploadInfo>* uploads) {
  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
  std::copy(uploads_.begin(),
            uploads_.begin() + std::min<size_t>(uploads_.size(), max_count),
            std::back_inserter(*uploads));
}