#include "entry.h"
#include "settings.h"
#include "creature.h"
#include "dice.h"
#include "weapon.h"
#include <iostream>
#include <vector>
#include <string>
#include <filesystem>
#include <system_error>
#include <exception>
#include <memory>
#include <algorithm>

namespace fs = std::filesystem;

void usage(const std::string& exename) {
    std::cout << "Usage:" << std::endl;
    std::string indOpt = "  " + exename + " ";
    std::string indDesc = "    ";
    std::cout << indOpt << "[ls] [subfolder]" << std::endl;
    std::cout << indDesc << "List creatures and objects." << std::endl;
    std::cout << indOpt << "cp old-path new-path" << std::endl;
    std::cout << indDesc << "Copy old-path to new-path, instantiating it." << std::endl;
    std::cout << indOpt << "mkdir path" << std::endl;
    std::cout << indDesc << "Make a new directory for holding creatures and objects." << std::endl;
    std::cout << indOpt << "mv old-path new-path" << std::endl;
    std::cout << indDesc << "Move old-path to new-path." << std::endl;
    std::cout << indOpt << "rm path" << std::endl;
    std::cout << indDesc << "Remove existing creature, object, or directory." << std::endl;
    std::cout << indOpt << "roll path name" << std::endl;
    std::cout << indDesc << "Roll a skill check, save, or attack." << std::endl;
    std::cout << indOpt << "damage path amount [type]" << std::endl;
    std::cout << indDesc << "Damage creature by amount. Type defaults to \"force\"." << std::endl;
    std::cout << indOpt << "heal path amount" << std::endl;
    std::cout << indDesc << "Heal creature by amount." << std::endl;
    std::cout << indOpt << "reset path" << std::endl;
    std::cout << indDesc << "Reset creature to full health (as if completing a long rest)." << std::endl;
    std::cout << indOpt << "set path field value" << std::endl;
    std::cout << indDesc << "Set a field to a new value, where field is any of:" << std::endl;
    std::cout << indDesc << "  ability (str, dex, con, int, wis, cha); value is new ability score" << std::endl;
    std::cout << indDesc << "  skill (athletics, \"sleight of hand\", etc.); value is (none|proficient|expert)" << std::endl;
    std::cout << indDesc << "  name; value is new given name." << std::endl;
    std::cout << indOpt << "edit path" << std::endl;
    std::cout << indDesc << "Edit notes associated to creature." << std::endl;
    std::cout << indOpt << "add path entry" << std::endl;
    std::cout << indDesc << "Add entry to creature, where entry is an item or spell." << std::endl;
    std::cout << indOpt << "help" << std::endl;
    std::cout << indDesc << "Show this help." << std::endl;
}

std::shared_ptr<entry::Entry> instantiate(const fs::path& path) {
    try {
        return entry::Entry::create(utils::loadJson(path));
    } catch(std::exception& e) {
        if(fs::directory_entry(path).exists()) {
            throw std::runtime_error("Invalid json: " + path.string());
        } else {
            throw std::runtime_error("No such file nor directory: " + path.string());
        }
    }
}

void save(const std::shared_ptr<entry::Entry>& e, const fs::path& path) {
    utils::saveJson(*e, path);
}

void print(const fs::path& path) {
    std::cout << instantiate(path)->getText() << std::endl;
}

fs::path getBaseDir() {
    return settings::getString("savedir");
}

fs::path eraseRoot(fs::path& src) {
    if(src.empty()) return src;
    fs::path tmp;
    auto it = src.begin();
    while(++it != src.end()) {
        tmp /= *it;
    }
    src = tmp;
    return src;
}

const std::vector<std::string> virtPaths({"weapons", "armor", "spells", "creatures"});

fs::path getTruePath(fs::path virtPath) {
    fs::path p;
    if(std::find(virtPaths.begin(), virtPaths.end(), *virtPath.begin()) != virtPaths.end()) {
        p = settings::getString(*virtPath.begin());
        eraseRoot(virtPath);
    } else {
        p = getBaseDir();
    }
    p /= virtPath;
    if(fs::directory_entry(p.string() + ".json").is_regular_file()) return p.string() + ".json";
    return p;
}

// Ensure the system is set up correctly
void initFS() {
    fs::directory_entry de = fs::directory_entry(getBaseDir());
    if(! de.exists()) {
        fs::create_directories(de);
    }
}

void list(const fs::path& p) {
    if(p.empty()) {
        // Print read-only dirs
        for(std::string name : virtPaths) {
            std::cout << name << "/ (read only)" << std::endl;
        }
    }
    fs::path truePath = getTruePath(p);
    if(fs::directory_entry(truePath).is_regular_file()) {
        print(truePath);
    }
    else if(fs::directory_entry(truePath).is_directory()) {
        for(fs::directory_entry de : fs::directory_iterator(truePath)) {
            if(de.is_directory()) {
                std::cout << de.path().filename().string() << "/" << std::endl;
            } else {
                std::cout << de.path().stem().string() << std::endl;
            }
        }
    }
    else {
        std::cerr << "Unknown path " << p << std::endl;
    }
}

void list(std::vector<std::string> args) {
    if(args.empty()) {
        list("");
    } else {
        for(std::string dir : args) {
            list(dir);
        }
    }
}

void mkdir(std::vector<std::string> args) {
    for(std::string s : args) {
        fs::create_directories(getTruePath(s));
    }
}

void cp(fs::path src, fs::path dest) {
    if(fs::directory_entry(src).is_regular_file()) {
        save(instantiate(src), dest);
    } else {
        mkdir({dest});
        for(fs::directory_entry de : fs::directory_iterator(src)) {
            cp(de.path(), dest / de.path().filename());
        }
    }

}

void cp(std::vector<std::string> args) {
    // Operate by intantiating and saving
    // We do recursive!
    cp(getTruePath(args[0]), getTruePath(args[1]));
}

void mv(std::vector<std::string> args) {
    fs::rename(getTruePath(args[0]), getTruePath(args[1]));
}

void rm(std::vector<std::string> args) {
    for(std::string s : args) {
        fs::remove_all(getTruePath(s));
    }
}

void roll(std::vector<std::string> args) {
    std::shared_ptr<entry::Entry> e = instantiate(getTruePath(args[0]));
    std::shared_ptr<creature::Creature> c = std::dynamic_pointer_cast<creature::Creature>(e);
    if(! c) {
        throw std::runtime_error("Subcommand 'roll' expected a creature but was given an instance of " + e->getType());
    }
    args.erase(args.begin());
    std::string rollName = utils::join(args, " ");
    std::transform(rollName.begin(), rollName.end(), rollName.begin(), ::tolower);
    int rolled = dice::roll(20);
    auto printResults = [](std::string name, std::string type, int rolled, int bonus) {
        std::cout << name << " " << type << ": " << rolled << " (d20) + " << bonus << " (" << name << " " << type << " bonus) = " << rolled + bonus << std::endl;
    };
    // Search through skills, saves, and attacks to roll
    try {
        rules::Skill skill = rules::Skill::string2skill(rollName);
        printResults(skill.getName(), "check", rolled, c->getSkillBonus(skill));
        return;
    } catch(std::exception& e) {} // eat.
    try {
        rules::Ability ability = rules::Ability::string2ability(rollName);
        printResults(ability.getFull(), "save", rolled, c->getAbilitySaveBonus(ability));
        return;
    } catch(std::exception& e) {} // eat.
    for(auto w : creature::getAttacks(*c)) {
        if(w->getName() == rollName) {
            std::cout << w->getText(*c) << std::endl;
            int abilityBonus = c->getBonus(creature::getBestAbility(getAbilityOptions(*w), *c));
            int bonus = abilityBonus + c->getProficiency();
            printResults(w->getName(), "attack", rolled, bonus);
            std::cout << "  on hit: " << entry::formatDmg(*w, *c) << std::endl;
            return;
        }
    }
}

void damage(std::vector<std::string> args) {
    fs::path p = getTruePath(args[0]);
    std::shared_ptr<entry::Entry> e = instantiate(p);
    std::shared_ptr<creature::Creature> c = std::dynamic_pointer_cast<creature::Creature>(e);
    if(! c) {
        throw std::runtime_error("Subcommand 'damage' expected a creature but was given an instance of " + e->getType());
    }
    int dmg = 0;
    try {
        dmg = std::stoi(args[1]);
    } catch(std::exception& e) {
        throw std::runtime_error("Subcommand 'damage' expected an integer but was given " + args[1]);
    }
    std::string dmgType = "force";
    if(args.size() == 3) {
        dmgType = args[2];
    }
    std::vector<std::string> qualifiers; // TODO
    int initHP = c->getHP();
    c->applyDamage(dmg, dmgType, qualifiers);
    std::cout << "Applying " << dmg << " " << dmgType << " damage to " << c->getGivenName() << " the " << c->getCreatureName() << ". HP: " << initHP << " -> " << c->getHP() << "." << std::endl;
    save(c, p);
}

void heal(std::vector<std::string> args) {
    fs::path p = getTruePath(args[0]);
    std::shared_ptr<entry::Entry> e = instantiate(p);
    std::shared_ptr<creature::Creature> c = std::dynamic_pointer_cast<creature::Creature>(e);
    if(! c) {
        throw std::runtime_error("Subcommand 'heal' expected a creature but was given an instance of " + e->getType());
    }
    int amnt = 0;
    try {
        amnt = std::stoi(args[1]);
    } catch(std::exception& e) {
        throw std::runtime_error("Subcommand 'heal' expected an integer but was given " + args[1]);
    }
    int initHP = c->getHP();
    c->applyHealing(amnt);
    std::cout << "Healing " << c->getGivenName() << " the " << c->getCreatureName() << " by " << amnt << ". HP: " << initHP << " -> " << c->getHP() << "." << std::endl;
    save(c, p);
}


void reset(std::vector<std::string> args) {}
void set(std::vector<std::string> args) {}
void add(std::vector<std::string> args) {}

const std::map<std::string, std::vector<int>> nargs({
        {"cp", {2}},
        {"mv", {2}},
        {"damage", {2, 3}},
        {"heal", {2}}
        });

void checkArgs(std::string cmd, std::vector<std::string> args) {
    if(nargs.contains(cmd)) {
        auto& allowed = nargs.at(cmd);
        if(std::find(allowed.begin(), allowed.end(), args.size()) == allowed.end()) {
            throw std::runtime_error("Subcommand '" + cmd + "' expected " + utils::join(allowed, ", ") + " arguments but got " + std::to_string(args.size()));
        }
    }
}

int main(int argc, char *argv[]) {
    std::string exename = argv[0];
    std::vector<std::string> args(&argv[1], &argv[argc]);
    try {
        initFS();
    } catch(fs::filesystem_error& e) {
        std::cerr << e.what() << std::endl;
        return 1;
    }
    if(args.empty()) {
        list(args);
        return 0;
    }
    std::string cmd = args[0];
    std::vector<std::string> argsOrig(args);
    args.erase(args.begin());
    try {
        checkArgs(cmd, args);
        if(cmd == "ls") list(args);
        else if(cmd == "cp") cp(args);
        else if(cmd == "mkdir") mkdir(args);
        else if(cmd == "mv") mv(args);
        else if(cmd == "rm") rm(args);
        else if(cmd == "roll") roll(args);
        else if(cmd == "damage") damage(args);
        else if(cmd == "heal") heal(args);
        else if(cmd == "reset") reset(args);
        else if(cmd == "set") set(args);
        else if(cmd == "add") add(args);
        else if(cmd == "help") usage(exename);
        else list(argsOrig);
    } catch(std::exception& e) {
        std::cerr << e.what() << std::endl;
        return 1;
    }
    return 0;
}