// Copyright 2016 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 "components/ntp_snippets/bookmarks/bookmark_last_visit_utils.h"

#include <algorithm>
#include <numeric>
#include <set>
#include <string>
#include <utility>

#include "base/bind.h"
#include "base/strings/string_number_conversions.h"
#include "base/time/time.h"
#include "components/bookmarks/browser/bookmark_model.h"
#include "components/bookmarks/browser/bookmark_node.h"
#include "url/gurl.h"

using bookmarks::BookmarkModel;
using bookmarks::BookmarkNode;

namespace ntp_snippets {

namespace {

struct RecentBookmark {
  const bookmarks::BookmarkNode* node;
  base::Time last_visited;
};

const char* kBookmarksURLBlacklist[] = {"chrome://newtab/",
                                        "chrome-native://newtab/",
                                        "chrome://bookmarks/"};

const char kBookmarkLastVisitDateOnMobileKey[] = "last_visited";
const char kBookmarkLastVisitDateOnDesktopKey[] = "last_visited_desktop";
const char kBookmarkDismissedFromNTP[] = "dismissed_from_ntp";

std::string FormatLastVisitDate(const base::Time& date) {
  return base::Int64ToString(date.ToInternalValue());
}

bool ExtractLastVisitDate(const BookmarkNode& node,
                          const std::string& meta_info_key,
                          base::Time* out) {
  std::string last_visit_date_string;
  if (!node.GetMetaInfo(meta_info_key, &last_visit_date_string)) {
    return false;
  }

  int64_t date = 0;
  if (!base::StringToInt64(last_visit_date_string, &date) || date < 0) {
    return false;
  }

  *out = base::Time::FromInternalValue(date);
  return true;
}

bool IsBlacklisted(const GURL& url) {
  for (const char* blacklisted : kBookmarksURLBlacklist) {
    if (url.spec() == blacklisted) {
      return true;
    }
  }
  return false;
}

std::vector<const BookmarkNode*>::const_iterator FindMostRecentBookmark(
    const std::vector<const BookmarkNode*>& bookmarks,
    bool consider_visits_from_desktop) {
  auto most_recent = bookmarks.end();
  base::Time most_recent_last_visited = base::Time::UnixEpoch();

  for (auto iter = bookmarks.begin(); iter != bookmarks.end(); ++iter) {
    base::Time last_visited;
    if (GetLastVisitDateForNTPBookmark(**iter, consider_visits_from_desktop,
                                       &last_visited) &&
        most_recent_last_visited <= last_visited) {
      most_recent = iter;
      most_recent_last_visited = last_visited;
    }
  }

  return most_recent;
}

}  // namespace

void UpdateBookmarkOnURLVisitedInMainFrame(BookmarkModel* bookmark_model,
                                           const GURL& url,
                                           bool is_mobile_platform) {
  // Skip URLs that are blacklisted.
  if (IsBlacklisted(url)) {
    return;
  }

  // Skip URLs that are not bookmarked.
  std::vector<const BookmarkNode*> bookmarks_for_url;
  bookmark_model->GetNodesByURL(url, &bookmarks_for_url);
  if (bookmarks_for_url.empty()) {
    return;
  }

  // If there are bookmarks for |url|, set their last visit date to now.
  std::string now = FormatLastVisitDate(base::Time::Now());
  for (const BookmarkNode* node : bookmarks_for_url) {
    bookmark_model->SetNodeMetaInfo(
        node, is_mobile_platform ? kBookmarkLastVisitDateOnMobileKey
                                 : kBookmarkLastVisitDateOnDesktopKey,
        now);
    // If the bookmark has been dismissed from NTP before, a new visit overrides
    // such a dismissal.
    bookmark_model->DeleteNodeMetaInfo(node, kBookmarkDismissedFromNTP);
  }
}

bool GetLastVisitDateForNTPBookmark(const BookmarkNode& node,
                                    bool consider_visits_from_desktop,
                                    base::Time* out) {
  if (IsDismissedFromNTPForBookmark(node)) {
    return false;
  }

  bool got_mobile_date =
      ExtractLastVisitDate(node, kBookmarkLastVisitDateOnMobileKey, out);

  if (consider_visits_from_desktop) {
    // Consider the later visit from these two platform groups.
    base::Time last_visit_desktop;
    if (ExtractLastVisitDate(node, kBookmarkLastVisitDateOnDesktopKey,
                             &last_visit_desktop)) {
      if (!got_mobile_date) {
        *out = last_visit_desktop;
      } else {
        *out = std::max(*out, last_visit_desktop);
      }
      return true;
    }
  }

  return got_mobile_date;
}

void MarkBookmarksDismissed(BookmarkModel* bookmark_model, const GURL& url) {
  std::vector<const BookmarkNode*> nodes;
  bookmark_model->GetNodesByURL(url, &nodes);
  for (const BookmarkNode* node : nodes) {
    bookmark_model->SetNodeMetaInfo(node, kBookmarkDismissedFromNTP, "1");
  }
}

bool IsDismissedFromNTPForBookmark(const BookmarkNode& node) {
  std::string dismissed_from_ntp;
  bool result =
      node.GetMetaInfo(kBookmarkDismissedFromNTP, &dismissed_from_ntp);
  DCHECK(!result || dismissed_from_ntp == "1");
  return result;
}

void MarkAllBookmarksUndismissed(BookmarkModel* bookmark_model) {
  // Get all the bookmark URLs.
  std::vector<BookmarkModel::URLAndTitle> bookmarks;
  bookmark_model->GetBookmarks(&bookmarks);

  // Remove dismissed flag from all bookmarks
  for (const BookmarkModel::URLAndTitle& bookmark : bookmarks) {
    std::vector<const BookmarkNode*> nodes;
    bookmark_model->GetNodesByURL(bookmark.url, &nodes);
    for (const BookmarkNode* node : nodes) {
      bookmark_model->DeleteNodeMetaInfo(node, kBookmarkDismissedFromNTP);
    }
  }
}

std::vector<const BookmarkNode*> GetRecentlyVisitedBookmarks(
    BookmarkModel* bookmark_model,
    int max_count,
    const base::Time& min_visit_time,
    bool consider_visits_from_desktop) {
  // Get all the bookmark URLs.
  std::vector<BookmarkModel::URLAndTitle> bookmark_urls;
  bookmark_model->GetBookmarks(&bookmark_urls);

  std::vector<RecentBookmark> bookmarks;
  // Find for each bookmark the most recently visited BookmarkNode and find out
  // whether it is visited since |min_visit_time|.
  for (const BookmarkModel::URLAndTitle& url_and_title : bookmark_urls) {
    // Skip URLs that are blacklisted.
    if (IsBlacklisted(url_and_title.url)) {
      continue;
    }

    // Get all bookmarks for the given URL.
    std::vector<const BookmarkNode*> bookmarks_for_url;
    bookmark_model->GetNodesByURL(url_and_title.url, &bookmarks_for_url);
    DCHECK(!bookmarks_for_url.empty());

    // Find the most recently visited node for the given URL.
    auto most_recent =
        FindMostRecentBookmark(bookmarks_for_url, consider_visits_from_desktop);
    if (most_recent == bookmarks_for_url.end()) {
      continue;
    }

    // Extract the last visit of the node to use later for sorting.
    base::Time last_visit_time;
    if (!GetLastVisitDateForNTPBookmark(
            **most_recent, consider_visits_from_desktop, &last_visit_time) ||
        last_visit_time <= min_visit_time) {
      continue;
    }

    bookmarks.push_back({*most_recent, last_visit_time});
  }

  // Sort the entries by date, getting the |max_count| most recent bookmarks
  // to the front.
  size_t count_to_sort =
      std::min(bookmarks.size(), static_cast<size_t>(max_count));
  std::partial_sort(bookmarks.begin(), bookmarks.begin() + count_to_sort,
                    bookmarks.end(),
                    [](const RecentBookmark& a, const RecentBookmark& b) {
                      return a.last_visited > b.last_visited;
                    });

  // Insert the first |max_count| items from |bookmarks| into |result|.
  std::vector<const BookmarkNode*> result;
  for (const RecentBookmark& bookmark : bookmarks) {
    result.push_back(bookmark.node);
    if (result.size() >= static_cast<size_t>(max_count)) {
      break;
    }
  }
  return result;
}

std::vector<const BookmarkNode*> GetDismissedBookmarksForDebugging(
    BookmarkModel* bookmark_model) {
  // Get all the bookmark URLs.
  std::vector<BookmarkModel::URLAndTitle> bookmarks;
  bookmark_model->GetBookmarks(&bookmarks);

  // Remove the bookmark URLs which have at least one non-dismissed bookmark.
  bookmarks.erase(
      std::remove_if(
          bookmarks.begin(), bookmarks.end(),
          [&bookmark_model](const BookmarkModel::URLAndTitle& bookmark) {
            std::vector<const BookmarkNode*> bookmarks_for_url;
            bookmark_model->GetNodesByURL(bookmark.url, &bookmarks_for_url);
            DCHECK(!bookmarks_for_url.empty());

            for (const BookmarkNode* node : bookmarks_for_url) {
              if (!IsDismissedFromNTPForBookmark(*node)) {
                return true;
              }
            }
            return false;
          }),
      bookmarks.end());

  // Insert into |result|.
  std::vector<const BookmarkNode*> result;
  for (const BookmarkModel::URLAndTitle& bookmark : bookmarks) {
    result.push_back(
        bookmark_model->GetMostRecentlyAddedUserNodeForURL(bookmark.url));
  }
  return result;
}

namespace {

void ClearLastVisitedMetadataIfBetween(bookmarks::BookmarkModel* model,
                                       const BookmarkNode& node,
                                       const base::Time& begin,
                                       const base::Time& end,
                                       const std::string& meta_key) {
  base::Time last_visit_time;
  if (ExtractLastVisitDate(node, meta_key, &last_visit_time) &&
      begin <= last_visit_time && last_visit_time <= end) {
    model->DeleteNodeMetaInfo(&node, meta_key);
  }
}

}  // namespace

void RemoveLastVisitedDatesBetween(const base::Time& begin,
                                   const base::Time& end,
                                   base::Callback<bool(const GURL& url)> filter,
                                   bookmarks::BookmarkModel* bookmark_model) {
  // Get all the bookmark URLs.
  std::vector<BookmarkModel::URLAndTitle> bookmark_urls;
  bookmark_model->GetBookmarks(&bookmark_urls);

  for (const BookmarkModel::URLAndTitle& url_and_title : bookmark_urls) {
    if (!filter.Run(url_and_title.url)) {
      continue;
    }
    // Get all bookmarks for the given URL.
    std::vector<const BookmarkNode*> bookmarks_for_url;
    bookmark_model->GetNodesByURL(url_and_title.url, &bookmarks_for_url);

    for (const BookmarkNode* bookmark : bookmarks_for_url) {
      // The dismissal metadata is managed by the BookmarkSuggestionsProvider.
      ClearLastVisitedMetadataIfBetween(bookmark_model, *bookmark, begin, end,
                                        kBookmarkLastVisitDateOnMobileKey);
      ClearLastVisitedMetadataIfBetween(bookmark_model, *bookmark, begin, end,
                                kBookmarkLastVisitDateOnDesktopKey);
    }
  }
}

}  // namespace ntp_snippets