#include <iostream>
#include <fstream>
#include <string>
#include <vector>
#include <map>
#include "/Users/aviralsrivastava/Desktop/vertica_ServerFault/stdc++.h"

using namespace std;

// Represents an entry in users.xml
// Some fields omitted due to laziness
struct User
{
    string Id;
    string DisplayName;
};

// Represents an entry in posts.xml
// Some fields omitted due to laziness
struct Post
{
    string Id;
    string PostTypeId;
    string OwnerUserId;
    string AcceptedAnswerId;
};

string parseFieldFromLine(const string &line, const string &key)
{
    // We're looking for a thing that looks like:
    // [key]="[value]"
    // as part of a larger string.
    // We are given [key], and want to return [value].

    // Find the start of the pattern
    string keyPattern = key + "=\"";
    ssize_t idx = line.find(keyPattern);

    // No match
    if (idx == -1)
        return "";

    // Find the closing quote at the end of the pattern
    size_t start = idx + keyPattern.size();

    size_t end = start;
    while (line[end] != '"')
    {
        end++;
    }

    // Extract [value] from the overall string and return it
    // We have (start, end); substr() requires,
    // so we must compute, (start, length).
    return line.substr(start, end - start);
}

// Keep track of all users
map<string, User> users;

void readUsers(const string &filename)
{
    ifstream fin;
    fin.open(filename.c_str());

    string line;
    while (getline(fin, line))
    {
        User u;
        u.Id = parseFieldFromLine(line, "Id");
        u.DisplayName = parseFieldFromLine(line, "DisplayName");
        users[u.Id] = u;
    }
}

// Keep track of all posts
map<string, Post> posts;

void readPosts(const string &filename)
{
    ifstream fin;
    fin.open(filename.c_str());

    string line;
    while (getline(fin, line))
    {
        Post p;
        p.Id = parseFieldFromLine(line, "Id");
        p.PostTypeId = parseFieldFromLine(line, "PostTypeId");
        p.OwnerUserId = parseFieldFromLine(line, "OwnerUserId");
        p.AcceptedAnswerId = parseFieldFromLine(line, "AcceptedAnswerId");
        posts[p.Id] = p;
    }
}

User findUser(const string &Id)
{
    if (users.find(Id) != users.end())
    {
        return users[Id];
    }
    return User();
}

// Some data for the map
struct MapData
{
    string DisplayName;
    int Count;
};

Post findPost(const string &Id)
{
    if (posts.find(Id) != posts.end())
    {
        return posts[Id];
    }
    return Post();
}

int main(int argv, char **argc)
{
    // Load our data
    readUsers("users-short.xml");
    readPosts("posts-short.xml");

    // Calculate the users with the most answers
    map<string, MapData> answers;

    for (map<string, Post>::iterator ite = posts.begin(); ite != posts.end(); ite++)
    {
        Post p = ite->second;
        answers[p.OwnerUserId].DisplayName = "";
        if (p.PostTypeId == "2")
        {
            answers[p.OwnerUserId].Count++;
        }
    }

    cout << "Top 10 users with the most answers:" << endl;
    for (int i = 0; i < 10; i++)
    {
        string key;
        MapData max_data = {"", 0};
        for (map<string, MapData>::iterator it = answers.begin();
             it != answers.end(); ++it)
        {
            if (it->second.Count >= max_data.Count)
            {
                key = it->first;
                max_data = it->second;
            }
        }

        answers.erase(key);
        cout << max_data.Count << '\t' << findUser(key).DisplayName << endl;
    }
    // Calculate the users with the most accepted answers
    map<string, MapData> acceptedAnswers;

    for (map<string, Post>::iterator ite2 = posts.begin(); ite2 != posts.end(); ite2++)
    {
        Post post = ite2->second;
        if (post.PostTypeId == "1" && post.AcceptedAnswerId != "")
        {
            Post answerPost = findPost(post.AcceptedAnswerId);
            if (answerPost.PostTypeId != "2")
                continue;
            acceptedAnswers[answerPost.OwnerUserId].DisplayName = "";
            acceptedAnswers[answerPost.OwnerUserId].Count++;
        }
    }

    cout << "Top 10 users with the most accepted answers:" << endl;
    for (int i = 0; i < 10; i++)
    {
        string key;
        MapData max_data = {"", 0};
        for (map<string, MapData>::iterator it = acceptedAnswers.begin();
             it != acceptedAnswers.end(); ++it)
        {
            if (it->second.Count >= max_data.Count)
            {
                key = it->first;
                max_data = it->second;
            }
        }

        acceptedAnswers.erase(key);
        cout << max_data.Count << '\t' << findUser(key).DisplayName << endl;
    }

    cout << endl;

    return 0;
}