WebCC/example/rest_book_server/book_services.cc

#include "book_services.h"

#include <list>

#include "boost/lexical_cast.hpp"

////////////////////////////////////////////////////////////////////////////////

// In-memory test data.
// There should be some database in a real product.

class Book {
public:
  std::string id;
  std::string title;
  double price;

  bool IsNull() const {
    return id.empty();
  }
};

static const Book kNullBook{};

class BookStore {
public:
  BookStore() {
    // Prepare test data.
    books_.push_back({ "1", "Title1", 11.1 });
    books_.push_back({ "2", "Title2", 22.2 });
    books_.push_back({ "3", "Title3", 33.3 });
  }

  const std::list<Book>& books() const {
    return books_;
  }

  const Book& GetBook(const std::string& id) const {
    auto it = FindBook(id);
    return (it == books_.end() ? kNullBook : *it);
  }

  bool AddBook(const Book& new_book) {
    if (FindBook(new_book.id) == books_.end()) {
      books_.push_back(new_book);
      return true;
    }
    return false;
  }

  bool DeleteBook(const std::string& id) {
    auto it = FindBook(id);

    if (it != books_.end()) {
      books_.erase(it);
      return true;
    }

    return false;
  }

private:
  std::list<Book>::const_iterator FindBook(const std::string& id) const {
    return std::find_if(books_.begin(),
                        books_.end(),
                        [&id](const Book& book) { return book.id == id; });
  }

private:
  std::list<Book> books_;
};

static BookStore g_book_store;

////////////////////////////////////////////////////////////////////////////////

// Naively create JSON object for a book.
// You should use real JSON library in real product.
static std::string CreateBookJson(const Book& book) {
  std::string json = "{ ";
  json += "\"id\": " + book.id + ", ";
  json += "\"title\": " + book.title + ", ";
  json += "\"price\": " + std::to_string(book.price);
  json += " }";
  return json;
}

// Naively create JSON array object for a list of books.
// You should use real JSON library in real product.
static std::string CreateBookListJson(const std::list<Book>& books) {
  std::string json = "[ ";

  for (const Book& book : books) {
    json += CreateBookJson(book);
    json += ",";
  }

  // Remove last ','.
  if (!books.empty()) {
    json[json.size() - 1] = ' ';
  }

  json += "]";

  return json;
}

////////////////////////////////////////////////////////////////////////////////

bool BookListService::Handle(const std::string& http_method,
                             const std::vector<std::string>& url_sub_matches,
                             const std::string& request_content,
                             std::string* response_content) {
  if (http_method == webcc::kHttpGet) {
    *response_content = CreateBookListJson(g_book_store.books());
    return true;
  }

  return false;
}

////////////////////////////////////////////////////////////////////////////////

bool BookDetailService::Handle(const std::string& http_method,
                               const std::vector<std::string>& url_sub_matches,
                               const std::string& request_content,
                               std::string* response_content) {
  if (url_sub_matches.size() != 1) {
    return false;
  }

  const std::string& book_id = url_sub_matches[0];

  if (http_method == webcc::kHttpGet) {
    const Book& book = g_book_store.GetBook(book_id);

    if (book.IsNull()) {
      return false;
    }

    *response_content = CreateBookJson(book);

    return true;

  } else if (http_method == webcc::kHttpPost) {

  } else if (http_method == webcc::kHttpDelete) {

  }

  return false;
}