#include <fstream>
#include <iostream>
#include <sstream>
#include <unistd.h>
#include <map>
#include "stringutils.h"
#include "typer.h"
#include <dtl/dtl.hpp>


void Typer::ProcessFile(std::string fname)
{
    m_scrRow = 0;
    m_scrCol = 0;
    ReadFile(fname);
    ComputeDiffs();

    OnStart();

    for (size_t i = 0; i < m_lines.size(); i++)
    {
        Line& line = m_lines[i];

//        std::cout << "---------\n";

//        std::cout << "++ " << line.prio << " : " << line.index << " : [ ";
//        for (size_t j = 0; j < SIMILARITY_LINE_COUNT; j++)
//            std::cout << line.similarity[j] << " ";

//        std::cout << "] : " << line.text << "\n\n";

        std::pair<size_t, std::string> lineOut = std::make_pair(line.index, line.text);

        // Find insertion position
        auto insertRowIt = std::lower_bound(m_scrOutput.begin(), m_scrOutput.end(), lineOut);
        size_t insertRow = static_cast<size_t>(insertRowIt - m_scrOutput.begin());

        // Insert row - there are 5 cases
        // 1. we are on the previous row: End, Return, type row
        // 2. we are at (0, 0) and nothing is typed: type row
        // 3. we are on insertRow, Home + type row + press Return
        // 4. we must insert below last row, navigate to last row, End, Return, type row
        // 5. we are anywhere else, navigate to (insertRow, 0), press Return, go up and type row
        if (insertRow > 0 &&
                m_scrRow == insertRow - 1)
        {
            NavigateToCol(COL_END);
            Newline();
            TypeString(line.text);
        }
        else if (m_scrOutput.empty())
        {
            TypeString(line.text);
        }
        else if (m_scrRow == insertRow &&
                 insertRow < m_scrOutput.size() &&
                 m_scrOutput[insertRow].second.empty())
        {
            NavigateToCol(COL_HOME);
            TypeString(line.text);
            Newline();
        }
        else if (insertRow == m_scrOutput.size())
        {
            NavigateTo(insertRow - 1, COL_END);
            Newline();
            TypeString(line.text);
        }
        else
        {
            NavigateTo(insertRow, COL_HOME);
            Newline();
            NavigateToRow(insertRow);
            TypeString(line.text);
        }

        // Synchronize screen output
        m_scrOutput.insert(insertRowIt, lineOut);
    }
}

void Typer::TogglePaused()
{
    m_keyHandler->TogglePaused();
}

int Typer::GetLinePriority(std::string &line)
{
    int prio = 0;

    if (line.empty()) {
        return prio;
    }

    if (!std::isdigit(line[0])) {
        return prio;
    }

    std::istringstream stream(line);
    stream >> prio;

    line = line.substr(static_cast<size_t>(stream.tellg()) + 1u);
    return prio;
}

void Typer::ReadFile(std::string fname)
{
    std::ifstream in;
    std::string line;
    int prio;
    size_t index = 0;

    in.open(fname, std::ios::in);
    if (!in)
    {
        std::cerr << "Failed to open file " << fname << "\n";
        exit(2);
    }

    std::map<std::pair<int, size_t>, std::string> lines;
    while (std::getline(in, line))
    {
        trim(line);
        prio = GetLinePriority(line);
        lines.emplace(std::make_pair(prio, ++index), line);
    }

    // Put sorted lines in m_lines vector
    for (auto line : lines)
        m_lines.push_back(Line(line.first.first, line.first.second, line.second));
}

void Typer::ComputeDiffs()
{
    for (size_t i = 0; i < m_lines.size(); i++)
    {
        m_lines[i].similarity.fill(0);

        for (size_t j = 0; j < SIMILARITY_LINE_COUNT && j < i; j++)
        {
            std::string a = m_lines[i].text;
            std::string b = m_lines[i - j - 1].text;

            if (a.size() > 0 || b.size() > 10)
            {
                dtl::Diff<char, std::string> diff(a, b);
                diff.onOnlyEditDistance();
                diff.compose();
                long long dist = diff.getEditDistance();

                m_lines[i].similarity[j] = 1.0f - static_cast<float>(dist) / static_cast<float>(a.size() + b.size());
            }
            else
            {
                m_lines[i].similarity[j] = 1.0f;
            }
        }
    }
}

void Typer::Newline()
{
    KeyNewline();
    m_scrRow++;
    m_scrCol = 0;
}

void Typer::TypeString(std::string str)
{
    KeyString(str);
    m_scrCol = str.size();
}

void Typer::NavigateTo(size_t row, size_t col)
{
    NavigateToRow(row);
    NavigateToCol(col);
}

void Typer::NavigateToRow(size_t row)
{
    if (m_scrRow < row)
    {
        for (; m_scrRow < row && m_scrRow < m_scrOutput.size(); m_scrRow++)
        {
            KeyDown();
            m_scrCol = std::min(m_scrCol, m_scrOutput[m_scrRow].second.size());
        }
    }
    else
    {
        for (; m_scrRow > row; m_scrRow--)
        {
            KeyUp();
            m_scrCol = std::min(m_scrCol, m_scrOutput[m_scrRow].second.size());
        }
    }

    m_scrCol = std::min(m_scrCol, m_scrOutput[m_scrRow].second.size());
}

void Typer::NavigateToCol(size_t col)
{
    size_t rowLen = m_scrOutput[m_scrRow].second.size();

    if (col == COL_HOME && m_scrCol != 0) {
        KeyHome();
        m_scrCol = 0;
    }
    else if (col == COL_END && m_scrCol != rowLen) {
        KeyEnd();
        m_scrCol = rowLen;
    }
    else if (m_scrCol < col) {
        for (; m_scrCol < col && m_scrCol < rowLen; m_scrCol++) {
            KeyRight();
        }
    }
    else if (m_scrCol > col)
    {
        for (; m_scrCol > col; m_scrCol--) {
            KeyLeft();
        }
    }
}

bool Typer::IsKeyShifted(char c)
{
    static const std::string shiftedKeys = "~!@#$%^&*()_+{}:\"|<>?>";

    if (isalpha(c)) {
        return isupper(c);
    }
    if (isdigit(c)) {
        return false;
    }
    return (shiftedKeys.find(c) != std::string::npos);
}


void Typer::KeyUp()
{
    m_keyHandler->Key(SpecialKey::UP);
}

void Typer::KeyDown()
{
    m_keyHandler->Key(SpecialKey::DOWN);
}
void Typer::KeyLeft()
{
    m_keyHandler->Key(SpecialKey::LEFT);
}

void Typer::KeyRight()
{
    m_keyHandler->Key(SpecialKey::RIGHT);
}

void Typer::KeyHome()
{
    m_keyHandler->Key(SpecialKey::HOME);
}

void Typer::KeyEnd()
{
    m_keyHandler->Key(SpecialKey::END);
}

void Typer::KeyNewline()
{
    m_keyHandler->Key(SpecialKey::RETURN);
}

void Typer::KeyString(std::string str)
{
    for (char c : str)
        m_keyHandler->Key(c, IsKeyShifted(c) ? KM_SHIFT : KM_NONE);
}