#include "rename_object.hpp"
#include "functions.hpp"
#include <climits>
#include <iostream>
#include <memory>
#include <restbed>
#include <sstream>
#include <rapidjson/document.h>
#include <rapidjson/stringbuffer.h>
#include <rapidjson/writer.h>
#include <string>
#include <chrono>

#include "jwt.hpp"
#include "filesystem/filesystem.hpp"
#include "config/config.hpp"
#include "fileobject.hpp"

// TODO add customKeyOptions and customKeyDefault endpoints

std::vector<RenameLibrary> libraries{};
Configuration cfg;

void sendResponse(const std::string &response, int status_code, const std::shared_ptr< restbed::Session > &session) {
    session->close(status_code, response, { { "Content-Length", std::to_string(response.length()) }, { "Access-Control-Allow-Origin", "*" } });
}

void performPostFunc(const std::shared_ptr<restbed::Session> &session, const std::function<void(const std::shared_ptr<restbed::Session>, rapidjson::GenericDocument<rapidjson::UTF8<>>&)>& callback) {
    const auto request = session->get_request( );

    int content_length = request->get_header( "Content-Length", 0 );

    session->fetch( content_length, [callback]( const std::shared_ptr< restbed::Session > &session, const restbed::Bytes & body )
    {
        rapidjson::Document doc;
        doc.Parse(reinterpret_cast<const char*>(body.data()), body.size());
        if(doc.HasParseError()) {
            sendResponse("ERROR: Invalid body!", 401, session);
            return;
        }
        callback(session, doc);
    });
}

bool verifyLogin( const std::shared_ptr< restbed::Session > &session, rapidjson::GenericDocument<rapidjson::UTF8<>> &doc ) {
    if(doc.FindMember("token") == doc.MemberEnd() || !doc["token"].IsString()) {
        sendResponse("ERROR: Invalid token!", 401, session);
        return false;
    }
    const auto *token = doc["token"].GetString();
    auto res = verifyJWT(token);
    if(!res) {
        sendResponse("ERROR: Invalid token!", 401, session);
    }
    return res;
}

std::vector<std::pair<RenameLibrary*, size_t>> getLibraries() {
    std::vector<std::pair<RenameLibrary*, size_t>> result{};
    for(size_t i = 0; i < libraries.size(); i++) {
        result.emplace_back(&libraries[i], i);
    }
    return result;
}

std::string getLibrariesJson() {
    auto libraries = getLibraries();
    std::ostringstream result;
    result << "{\n  \"libraries\": [\n";
    if(!libraries.empty()) {
        for(const auto &library : libraries) {
            result << "  {\n    \"id\": " << library.second << ",\n";
            result << "    \"name\": \"" << safeJson(library.first->getName()) << "\"\n,";
            result << "    \"multiple_files\": " << (library.first->canRenameMultipleFiles() ? "true" : "false") << "\n  },\n";
        }
        result.seekp(-2, std::ios_base::end);
        result << "\n";
    }
    result << "  ]\n}";
    auto res = result.str();
    return res;
}

void getLibrariesRest( const std::shared_ptr< restbed::Session > &session ) {
    sendResponse(getLibrariesJson(), restbed::OK, session);
}

std::vector< RenameObject > getOptions(const RenameObject &search) {
    auto library_id = search.getLibraryId();
    if(library_id >= libraries.size()) {
        return {};
    }
    auto result = libraries[library_id].getOptions(search);
    for(auto &res : result) {
        res.setLibraryId(library_id);
    }
    return result;
}

std::string getOptionsJson(const RenameObject &search) {
    std::ostringstream res;
    res << "{\n  \"options\": [\n";
    auto options = getOptions(search);
    if(!options.empty()) {
        for(auto &option : options) {
            res << option.toJson();
            res << ",\n";
        }
        res.seekp( -2, std::ios_base::end );
        res << "\n";
    }
    res << "  ]\n}";
    auto result = res.str();
    return result;
}

void getOptionsRest( const std::shared_ptr< restbed::Session > &session, rapidjson::GenericDocument<rapidjson::UTF8<>> &doc )
{
    if(doc.HasParseError()) {
        sendResponse("ERROR: Invalid body!", 401, session);
        return;
    }
    if(!verifyLogin(session, doc)) {
        return;
    }
    if(doc.FindMember("info") == doc.MemberEnd() || !doc["info"].IsObject()) {
        sendResponse("ERROR: Invalid search!", 401, session);
        return;
    }
    RenameObject search;
    rapidjson::StringBuffer sb;
    rapidjson::Writer<rapidjson::StringBuffer> writer(sb);
    doc["info"].Accept(writer);
    std::string s = sb.GetString();
    search.fromJson(s);
    if(search.getPresentedName().empty()) {
        sendResponse("Empty search", 401, session);
        return;
    }
    sendResponse(getOptionsJson(search), 200, session);
}

std::vector< std::unordered_map< std::string, std::string > > getCustomKeys(size_t library_id) {
    if(library_id >= libraries.size()) {
        return {};
    }
    auto result = libraries[library_id].getCustomKeys();
    return result;
}

std::string getCustomKeysJson(size_t library_id) {
    std::ostringstream res;
    res << "{\n  \"custom_keys\": [\n";
    auto custom_keys = getCustomKeys(library_id);
    if(!custom_keys.empty()) {
        for(auto &key : custom_keys) {
            res << "    {\n";
            res << "      \"name\": \"" << safeJson(key["name"]) << "\",\n";
            res << "      \"type\": \"" << safeJson(key["type"]) << "\",\n";
            res << "      \"input\": \"" << safeJson(key["input"]) << "\"\n";
            res << "    },\n";
        }
        res.seekp( -2, std::ios_base::end );
        res << "\n";
    }
    res << "  ]\n}";
    return res.str();
}

void getCustomKeysRest( const std::shared_ptr< restbed::Session > &session, rapidjson::GenericDocument<rapidjson::UTF8<>> &doc )
{
    if(doc.FindMember("library_id") == doc.MemberEnd() || !doc["library_id"].IsUint64()) {
        sendResponse("ERROR: Invalid library_id!", 401, session);
        return;
    }
    size_t library_id = doc["library_id"].GetUint64();
    sendResponse(getCustomKeysJson(library_id), 200, session);
}

std::pair<bool, std::string> renamePath(std::string path, const RenameObject &renamer) {
    if(renamer.getLibraryId() >= libraries.size()) {
        return {false, "Invalid library id"};
    }
    if(path[0] != '/') {
        path = cfg.getSourcePath() + "/" + path;
    }

    auto canon_path = FSLib::canonical(path);
    if(canon_path.substr(0, cfg.getSourcePath().length()) != cfg.getSourcePath()) {
        return {false, "Invalid path"};
    }

    if(!FSLib::exists(path)) {
        return {false, "Source doesn't exist"};
    }
    return {libraries[renamer.getLibraryId()].renamePath(path, renamer), "Library error"};
}

std::string renamePathJson(const std::string &path, const RenameObject &renamer) {
    std::ostringstream res;
    res << "{\n  \"success\": ";
    auto rename_result = renamePath(path, renamer);
    if(rename_result.first) {
        res << "true";
    } else {
        res << "false";
    }
    res << ",\n";
    if(!rename_result.first) {
        res << "  \"error\": \"" << safeJson(rename_result.second) << "\"\n";
    }
    res << "}";
    return res.str();
}

void renamePathRest( const std::shared_ptr< restbed::Session > &session, rapidjson::GenericDocument<rapidjson::UTF8<>> &doc ) {
    if(!verifyLogin(session, doc)) {
        return;
    }
    if(doc.FindMember("path") == doc.MemberEnd() || !doc["path"].IsString()) {
        // TODO validate path, also validate against config
        sendResponse("ERROR: Invalid path!", 401, session);
        return;
    }
    if(doc.FindMember("info") == doc.MemberEnd() || !doc["info"].IsObject()) {
        sendResponse("ERROR: Invalid info!", 401, session);
        return;
    }
    std::string path = doc["path"].GetString();
    RenameObject renamer;
    rapidjson::StringBuffer sb;
    rapidjson::Writer<rapidjson::StringBuffer> writer(sb);
    doc["info"].Accept(writer);
    std::string s = sb.GetString();
    renamer.fromJson(s);
    sendResponse(renamePathJson(path, renamer), 200, session);
}

std::string getFilesJson() {
    std::ostringstream res;
    res << "{\n  \"files\": [\n";
    auto files = getFilesInSource(cfg.getSourcePath());
    if(!files.empty()) {
        for(const auto &file : files) {
            res << "    {\n      \"path\": \"" << safeJson(file.getPath()) << "\",\n";
            res << "      \"depth\": " << file.getDepth() << ",\n";
            res << "      \"type\": \"" << (file.getFileType() == TYPE_FILE ? "file" : "directory") << "\"\n    },\n";
        }
        res.seekp(-2, std::ios_base::end);
    }
    res << "\n  ]\n}";
    return res.str();
}

void getFilesRest( const std::shared_ptr< restbed::Session > &session, rapidjson::GenericDocument<rapidjson::UTF8<>> &doc )
{
    if(!verifyLogin(session, doc)) {
        return;
    }
    sendResponse(getFilesJson(), restbed::OK, session);
}

std::vector<std::pair<uint64_t, std::string>> getTargets() {
    std::vector<std::pair<uint64_t, std::string>> result;
    const auto &targets = cfg.getTargetPaths();
    for(uint64_t i = 0; i < targets.size(); i++) {
        result.emplace_back(i, targets[i].second);
    }
    return result;
}

std::string getTargetsJson() {
    std::ostringstream res;
    res << "{\n  \"targets\": [\n";
    auto targets = getTargets();
    if(!targets.empty()) {
        for(const auto &target : targets) {
            res << "  {\n" << "    \"id\": " << target.first << ",\n";
            res << "    \"name\": \"" << safeJson(target.second) << "\"\n  },\n";
        }
        res.seekp(-2, std::ios_base::end);
    }
    res << "\n  ]\n}";
    return res.str();
}

void getTargetsRest( const std::shared_ptr< restbed::Session > &session, rapidjson::GenericDocument<rapidjson::UTF8<>> &doc )
{
    if(!verifyLogin(session, doc)) {
        return;
    }
    sendResponse(getTargetsJson(), restbed::OK, session);
}

std::string getTargetDirectoriesJson(uint64_t id) {
    if(id >= cfg.getTargetPaths().size()) {
        return "";
    }
    std::ostringstream res;
    res << "{\n  \"target_directories\": [\n";
    auto dirs = getTargetDirectories(cfg.getTargetPaths()[id].first);
    if(!dirs.empty()) {
        for(const auto &dir : dirs) {
            res << "  \"" << safeJson(dir.getPath()) << "\",\n";
        }
        res.seekp(-2, std::ios_base::end);
    }
    res << "\n  ]\n}";
    return res.str();
}

void getTargetDirectoriesRest( const std::shared_ptr< restbed::Session > &session, rapidjson::GenericDocument<rapidjson::UTF8<>> &doc )
{
    if(!verifyLogin(session, doc)) {
        return;
    }
    uint64_t id = 0;
    if(doc.FindMember("path_id") == doc.MemberEnd() || !doc["path_id"].IsUint64() || (id = doc["path_id"].GetUint64()) >= cfg.getTargetPaths().size()) {
        sendResponse("ERROR: Invalid path_id!", 401, session);
        return;
    }
    sendResponse(getTargetDirectoriesJson(id), restbed::OK, session);
}

std::pair<bool, std::string> move(std::string path, uint64_t target_id, const std::string &containing_dir) {
    if(path[0] != '/') {
        path = cfg.getSourcePath() + "/" + path;
    }
    auto canon_path = FSLib::canonical(path);
    if(canon_path.substr(0, cfg.getSourcePath().length()) != cfg.getSourcePath()) {
        return {false, "Invalid path"};
    }

    if(target_id >= cfg.getTargetPaths().size()) {
        return {false, "Invalid target_id"};
    }
    if(!FSLib::exists(path)) {
        return {false, "Source doesn't exist"};
    }
    auto target_start = cfg.getTargetPaths()[target_id].first;
    auto target_dir = target_start + FSLib::dir_divisor + containing_dir;
    auto target_canon = FSLib::canonical(target_dir);
    if(target_canon.substr(0, target_start.length()) != target_start && !target_canon.empty()) {
        return {false, "Invalid target"};
    }
    // might result in needless false positives, but better be safe than sorry
    if(target_canon.empty() && target_dir.find("..") != std::string::npos ) {
        return {false, "Invalid target"};
    }
    if(!FSLib::exists(target_dir)) {
        FSLib::createDirectoryFull(target_dir);
    }
    return {FSLib::rename(path, target_dir + FSLib::dir_divisor + FSLib::getFileName(path)), "Library error"};
}

std::string moveJson(const std::string &path, uint64_t target_id, const std::string &containing_dir) {
    std::ostringstream res;
    res << "{\n  \"success\": ";
    auto move_result = move(path, target_id, containing_dir);
    if(move_result.first) {
        res << "true";
    } else {
        res << "false";
    }
    res << ",\n";
    if(!move_result.first) {
        res << "  \"error\": \"" << safeJson(move_result.second) << "\"\n";
    }
    res << "}";
    return res.str();
}

void moveRest( const std::shared_ptr< restbed::Session > &session, rapidjson::GenericDocument<rapidjson::UTF8<>> &doc )
{
    if(!verifyLogin(session, doc)) {
        return;
    }
    std::string containing_dir;
    if(doc.FindMember("path") == doc.MemberEnd() || !doc["path"].IsString()) {
        // TODO validate path, also validate against config
        sendResponse("ERROR: Invalid path!", 401, session);
        return;
    }
    uint64_t id = 0;
    if(doc.FindMember("target_id") == doc.MemberEnd() || !doc["target_id"].IsUint64() || (id = doc["target_id"].GetUint64()) >= cfg.getTargetPaths().size()) {
        sendResponse("ERROR: Invalid target_id!", 401, session);
        return;
    }
    if(doc.FindMember("containing_dir") != doc.MemberEnd() && doc["containing_dir"].IsString()) {
        containing_dir = doc["containing_dir"].GetString();
    }
    std::string path = doc["path"].GetString();
    // TODO correct response code
    sendResponse(moveJson(path, id, containing_dir), 200, session);
}

std::pair<bool, std::string> remove(std::string path) {
    if(path[0] != '/') {
        path = cfg.getSourcePath() + "/" + path;
    }

    auto canon_path = FSLib::canonical(path);
    if(canon_path.substr(0, cfg.getSourcePath().length()) != cfg.getSourcePath()) {
        return {false, "Invalid path"};
    }

    if(!FSLib::exists(path)) {
        return {false, "Source doesn't exist"};
    }
    return {FSLib::deleteFile(path), "Library error"};
}

std::string removeJson(const std::string &path) {
    std::ostringstream res;
    res << "{\n  \"success\": ";
    auto remove_result = remove(path);
    if(remove_result.first) {
        res << "true";
    } else {
        res << "false";
    }
    res << ",\n";
    if(!remove_result.first) {
        res << "  \"error\": \"" << safeJson(remove_result.second) << "\"\n";
    }
    res << "}";
    return res.str();
}

void removeRest( const std::shared_ptr< restbed::Session > &session, rapidjson::GenericDocument<rapidjson::UTF8<>> &doc )
{
    if(!verifyLogin(session, doc)) {
        return;
    }
    if(doc.FindMember("path") == doc.MemberEnd() || !doc["path"].IsString()) {
        // TODO validate path, also validate against config
        sendResponse("ERROR: Invalid path!", 401, session);
        return;
    }
    std::string path = doc["path"].GetString();
    // TODO correct response code
    sendResponse(removeJson(path), 200, session);
}

std::string loginJson(const std::string &user) {
    std::ostringstream res;
    res << "{\n  \"token\": \"" << createLoginToken(user) << "\"\n}";
    return res.str();
}

void loginRest( const std::shared_ptr< restbed::Session > &session, rapidjson::GenericDocument<rapidjson::UTF8<>> &doc ) {
    if(doc.FindMember("user") == doc.MemberEnd() || !doc["user"].IsString()) {
        sendResponse("ERROR: Invalid user!", 401, session);
        return;
    }
    if(doc.FindMember("password") == doc.MemberEnd() || !doc["password"].IsString()) {
        sendResponse("ERROR: Invalid password!", 401, session);
        return;
    }
    const auto *user = doc["user"].GetString();
    const auto *password = doc["password"].GetString();
    bool valid = false;
    for(const auto &user_cfg : cfg.getUsers()) {
        if(user_cfg.first == user) {
            valid = user_cfg.second == password;
            break;
        }
    }
    if(valid) {
        sendResponse(loginJson(user), 200, session);
    } else {
        sendResponse("Invalid user/password", 401, session);
    }
}

void getOptionsCall(const std::shared_ptr<restbed::Session> &session) {
    performPostFunc(session, getOptionsRest);
}

void getCustomKeysCall(const std::shared_ptr<restbed::Session> &session) {
    performPostFunc(session, getCustomKeysRest);
}

void renameCall(const std::shared_ptr<restbed::Session> &session) {
    performPostFunc(session, renamePathRest);
}

void getFilesCall(const std::shared_ptr<restbed::Session> &session) {
    performPostFunc(session, getFilesRest);
}

void getTargetsCall(const std::shared_ptr<restbed::Session> &session) {
    performPostFunc(session, getTargetsRest);
}

void getTargetDirectoriesCall(const std::shared_ptr<restbed::Session> &session) {
    performPostFunc(session, getTargetDirectoriesRest);
}

void moveCall(const std::shared_ptr<restbed::Session> &session) {
    performPostFunc(session, moveRest);
}

void removeCall(const std::shared_ptr<restbed::Session> &session) {
    performPostFunc(session, removeRest);
}

void loginCall(const std::shared_ptr<restbed::Session> &session) {
    performPostFunc(session, loginRest);
}

int main(int argc, char **argv) {
    cfg.readConfiguration("/etc/renameserver/main.cfg");

    libraries = getLibraries(cfg.getLibraries());
    for(auto &library : libraries) {
        library.init(library.config);
    }

    restbed::Service service;

    auto get_libraries = std::make_shared< restbed::Resource >();
    get_libraries->set_path("/get_libraries");
    get_libraries->set_method_handler( "GET", getLibrariesRest );
    service.publish(get_libraries);

    auto search = std::make_shared< restbed::Resource >();
    search->set_path("/search");
    search->set_method_handler( "POST", getOptionsCall );
    service.publish(search);

    auto custom_fields = std::make_shared< restbed::Resource >();
    custom_fields->set_path("/get_custom_fields");
    custom_fields->set_method_handler( "POST", getCustomKeysCall );
    service.publish(custom_fields);

    auto rename_path = std::make_shared< restbed::Resource >();
    rename_path->set_path("/rename");
    rename_path->set_method_handler( "POST", renameCall );
    service.publish(rename_path);

    auto get_files = std::make_shared< restbed::Resource >();
    get_files->set_path("/get_files");
    get_files->set_method_handler( "POST", getFilesCall );
    service.publish(get_files);

    auto get_targets = std::make_shared< restbed::Resource >();
    get_targets->set_path("/get_targets");
    get_targets->set_method_handler( "POST", getTargetsCall );
    service.publish(get_targets);

    auto get_target_directories = std::make_shared< restbed::Resource >();
    get_target_directories->set_path("/get_target_directories");
    get_target_directories->set_method_handler( "POST", getTargetDirectoriesCall );
    service.publish(get_target_directories);

    auto move = std::make_shared< restbed::Resource >();
    move->set_path("/move");
    move->set_method_handler( "POST", moveCall );
    service.publish(move);

    auto remove = std::make_shared< restbed::Resource >();
    remove->set_path("/remove");
    remove->set_method_handler( "POST", removeCall );
    service.publish(remove);

    auto login = std::make_shared< restbed::Resource >();
    login->set_path("/login");
    login->set_method_handler( "POST", loginCall );
    service.publish(login);

    auto settings = std::make_shared< restbed::Settings >();
    settings->set_port(1984);
    settings->set_default_header( "Connection", "close" );

    service.start(settings);

    return 0;
}