#include "core/params.hpp"

#include <algorithm>

namespace effector {

std::string ParamSpec::flag() const {
    std::string flag = "--" + key;
    std::replace(flag.begin(), flag.end(), '_', '-');
    return flag;
}

ParamSpec ParamSpec::makeInt(std::string key, std::string label, long defaultValue, long minimum,
                             long maximum, std::string help, long step) {
    ParamSpec spec;
    spec.type = Type::Int;
    spec.key = std::move(key);
    spec.label = std::move(label);
    spec.help = std::move(help);
    spec.defaultValue = static_cast<double>(defaultValue);
    spec.minimum = static_cast<double>(minimum);
    spec.maximum = static_cast<double>(maximum);
    spec.step = static_cast<double>(step);
    return spec;
}

ParamSpec ParamSpec::makeDouble(std::string key, std::string label, double defaultValue,
                                double minimum, double maximum, std::string help, double step,
                                int digits) {
    ParamSpec spec;
    spec.type = Type::Double;
    spec.key = std::move(key);
    spec.label = std::move(label);
    spec.help = std::move(help);
    spec.defaultValue = defaultValue;
    spec.minimum = minimum;
    spec.maximum = maximum;
    spec.step = step;
    spec.digits = digits;
    return spec;
}

ParamSpec ParamSpec::makeBool(std::string key, std::string label, bool defaultValue,
                              std::string help) {
    ParamSpec spec;
    spec.type = Type::Bool;
    spec.key = std::move(key);
    spec.label = std::move(label);
    spec.help = std::move(help);
    spec.defaultValue = defaultValue ? 1.0 : 0.0;
    return spec;
}

ParamSpec ParamSpec::makeChoice(std::string key, std::string label, std::string defaultChoice,
                                std::vector<std::string> choices, std::string help) {
    ParamSpec spec;
    spec.type = Type::Choice;
    spec.key = std::move(key);
    spec.label = std::move(label);
    spec.help = std::move(help);
    spec.defaultChoice = std::move(defaultChoice);
    spec.choices = std::move(choices);
    return spec;
}

ParamSpec ParamSpec::makePath(std::string key, std::string label, std::string help) {
    ParamSpec spec;
    spec.type = Type::Path;
    spec.key = std::move(key);
    spec.label = std::move(label);
    spec.help = std::move(help);
    return spec;
}

ParamSpec ParamSpec::makeText(std::string key, std::string label, std::string defaultText,
                              std::string help) {
    ParamSpec spec;
    spec.type = Type::Text;
    spec.key = std::move(key);
    spec.label = std::move(label);
    spec.help = std::move(help);
    spec.defaultChoice = std::move(defaultText);
    return spec;
}

ParamSpec ParamSpec::makeColor(std::string key, std::string label, std::string defaultColor,
                               std::string help) {
    ParamSpec spec;
    spec.type = Type::Color;
    spec.key = std::move(key);
    spec.label = std::move(label);
    spec.help = std::move(help);
    spec.defaultChoice = std::move(defaultColor);
    return spec;
}

namespace {

const ParamValue* find(const ParamValues& values, const std::string& key) {
    const auto it = values.find(key);
    return it == values.end() ? nullptr : &it->second;
}

}  // namespace

long paramInt(const ParamValues& values, const std::string& key, long fallback) {
    if (const auto* value = find(values, key)) {
        if (const auto* v = std::get_if<long>(value)) return *v;
        if (const auto* v = std::get_if<double>(value)) return static_cast<long>(*v);
        if (const auto* v = std::get_if<bool>(value)) return *v ? 1 : 0;
    }
    return fallback;
}

double paramDouble(const ParamValues& values, const std::string& key, double fallback) {
    if (const auto* value = find(values, key)) {
        if (const auto* v = std::get_if<double>(value)) return *v;
        if (const auto* v = std::get_if<long>(value)) return static_cast<double>(*v);
    }
    return fallback;
}

bool paramBool(const ParamValues& values, const std::string& key, bool fallback) {
    if (const auto* value = find(values, key)) {
        if (const auto* v = std::get_if<bool>(value)) return *v;
        if (const auto* v = std::get_if<long>(value)) return *v != 0;
    }
    return fallback;
}

std::string paramChoice(const ParamValues& values, const std::string& key,
                        const std::string& fallback) {
    return paramText(values, key, fallback);
}

std::string paramText(const ParamValues& values, const std::string& key,
                      const std::string& fallback) {
    if (const auto* value = find(values, key)) {
        if (const auto* v = std::get_if<std::string>(value)) return *v;
    }
    return fallback;
}

namespace {

int hexDigit(char c) {
    if (c >= '0' && c <= '9') return c - '0';
    if (c >= 'a' && c <= 'f') return c - 'a' + 10;
    if (c >= 'A' && c <= 'F') return c - 'A' + 10;
    return -1;
}

}  // namespace

bool parseColor(const std::string& text, std::uint8_t rgb[3]) {
    std::string digits = text;
    if (!digits.empty() && digits.front() == '#') digits.erase(digits.begin());
    if (digits.size() != 3 && digits.size() != 6) return false;

    int parsed[6];
    for (std::size_t i = 0; i < digits.size(); ++i) {
        parsed[i] = hexDigit(digits[i]);
        if (parsed[i] < 0) return false;
    }
    for (int c = 0; c < 3; ++c) {
        // "#abc" is the usual shorthand for "#aabbcc".
        const int value = digits.size() == 3 ? parsed[c] * 17 : parsed[c * 2] * 16 + parsed[c * 2 + 1];
        rgb[c] = static_cast<std::uint8_t>(value);
    }
    return true;
}

std::string formatColor(const std::uint8_t rgb[3]) {
    static const char* const kDigits = "0123456789abcdef";
    std::string text = "#";
    for (int c = 0; c < 3; ++c) {
        text += kDigits[rgb[c] >> 4];
        text += kDigits[rgb[c] & 0x0F];
    }
    return text;
}

void paramColor(const ParamValues& values, const std::string& key, const std::string& fallback,
                std::uint8_t rgb[3]) {
    if (parseColor(paramText(values, key, fallback), rgb)) return;
    if (parseColor(fallback, rgb)) return;
    rgb[0] = rgb[1] = rgb[2] = 0;
}

}  // namespace effector