#pragma once

#include <cstddef>
#include <functional>

#include "esp_attr.h"

#define ISR_TRAMPOLINE_FUNC(slot) \
static void IRAM_ATTR trampoline##slot() { static const int DRAM_ATTR i = slot; auto &f = IsrTrampolines::functions[i]; if (f) f(); }

class IsrTrampolines {

public:

    typedef std::size_t SlotNumber;
    static constexpr SlotNumber MAX_SLOTS = 32;
    using TrampolinePointer = void (*)();
    using VoidFunction = std::function<void()>;
    static std::array<VoidFunction, MAX_SLOTS> functions;
    static void (*const trampolines[MAX_SLOTS])();

    static bool registerSlot(VoidFunction f, SlotNumber& slotRegistered) {
        for (SlotNumber slot = 0; slot < MAX_SLOTS; ++slot) {
            if (!functions[slot]) {
                slotRegistered = slot;
                functions[slot] = f;
                return true;
            }
        }

        return false;
    }

    static bool unregisterSlot(const SlotNumber slotRegistered) {
        if (!functions[slotRegistered]) {
            return false;
        }

        functions[slotRegistered] = nullptr;
        return true;
    }

    static TrampolinePointer getForSlot(const SlotNumber slotRegistered) {
        if (slotRegistered < MAX_SLOTS) {
            return trampolines[slotRegistered];
        }
        return nullptr;
    }

    // Unfortunately, these cannot be templated because the linker cannot correctly handle
    // its integer constant indexing the function table (dangerous relocation)
    ISR_TRAMPOLINE_FUNC(0);
    ISR_TRAMPOLINE_FUNC(1);
    ISR_TRAMPOLINE_FUNC(2);
    ISR_TRAMPOLINE_FUNC(3);
    ISR_TRAMPOLINE_FUNC(4);
    ISR_TRAMPOLINE_FUNC(5);
    ISR_TRAMPOLINE_FUNC(6);
    ISR_TRAMPOLINE_FUNC(7);
    ISR_TRAMPOLINE_FUNC(8);
    ISR_TRAMPOLINE_FUNC(9);
    ISR_TRAMPOLINE_FUNC(10);
    ISR_TRAMPOLINE_FUNC(11);
    ISR_TRAMPOLINE_FUNC(12);
    ISR_TRAMPOLINE_FUNC(13);
    ISR_TRAMPOLINE_FUNC(14);
    ISR_TRAMPOLINE_FUNC(15);
    ISR_TRAMPOLINE_FUNC(16);
    ISR_TRAMPOLINE_FUNC(17);
    ISR_TRAMPOLINE_FUNC(18);
    ISR_TRAMPOLINE_FUNC(19);
    ISR_TRAMPOLINE_FUNC(20);
    ISR_TRAMPOLINE_FUNC(21);
    ISR_TRAMPOLINE_FUNC(22);
    ISR_TRAMPOLINE_FUNC(23);
    ISR_TRAMPOLINE_FUNC(24);
    ISR_TRAMPOLINE_FUNC(25);
    ISR_TRAMPOLINE_FUNC(26);
    ISR_TRAMPOLINE_FUNC(27);
    ISR_TRAMPOLINE_FUNC(28);
    ISR_TRAMPOLINE_FUNC(29);
    ISR_TRAMPOLINE_FUNC(30);
    ISR_TRAMPOLINE_FUNC(31);

    /*static void IRAM_ATTR trampoline0()  ISR_TRAMPOLINE_FUNC(0)
    static void IRAM_ATTR trampoline1()  { auto &f = IsrTrampolines::functions[1];  if (f) f(); }
    static void IRAM_ATTR trampoline2()  { auto &f = IsrTrampolines::functions[2];  if (f) f(); }
    static void IRAM_ATTR trampoline3()  { auto &f = IsrTrampolines::functions[3];  if (f) f(); }
    static void IRAM_ATTR trampoline4()  { auto &f = IsrTrampolines::functions[4];  if (f) f(); }
    static void IRAM_ATTR trampoline5()  { auto &f = IsrTrampolines::functions[5];  if (f) f(); }
    static void IRAM_ATTR trampoline6()  { auto &f = IsrTrampolines::functions[6];  if (f) f(); }
    static void IRAM_ATTR trampoline7()  { auto &f = IsrTrampolines::functions[7];  if (f) f(); }
    static void IRAM_ATTR trampoline8()  { auto &f = IsrTrampolines::functions[8];  if (f) f(); }
    static void IRAM_ATTR trampoline9()  { auto &f = IsrTrampolines::functions[9];  if (f) f(); }
    static void IRAM_ATTR trampoline10() { auto &f = IsrTrampolines::functions[10]; if (f) f(); }
    static void IRAM_ATTR trampoline11() { auto &f = IsrTrampolines::functions[11]; if (f) f(); }
    static void IRAM_ATTR trampoline12() { auto &f = IsrTrampolines::functions[12]; if (f) f(); }
    static void IRAM_ATTR trampoline13() { auto &f = IsrTrampolines::functions[13]; if (f) f(); }
    static void IRAM_ATTR trampoline14() { auto &f = IsrTrampolines::functions[14]; if (f) f(); }
    static void IRAM_ATTR trampoline15() { auto &f = IsrTrampolines::functions[15]; if (f) f(); }
    static void IRAM_ATTR trampoline16() { auto &f = IsrTrampolines::functions[16]; if (f) f(); }
    static void IRAM_ATTR trampoline17() { auto &f = IsrTrampolines::functions[17]; if (f) f(); }
    static void IRAM_ATTR trampoline18() { auto &f = IsrTrampolines::functions[18]; if (f) f(); }
    static void IRAM_ATTR trampoline19() { auto &f = IsrTrampolines::functions[19]; if (f) f(); }
    static void IRAM_ATTR trampoline20() { auto &f = IsrTrampolines::functions[20]; if (f) f(); }
    static void IRAM_ATTR trampoline21() { auto &f = IsrTrampolines::functions[21]; if (f) f(); }
    static void IRAM_ATTR trampoline22() { auto &f = IsrTrampolines::functions[22]; if (f) f(); }
    static void IRAM_ATTR trampoline23() { auto &f = IsrTrampolines::functions[23]; if (f) f(); }
    static void IRAM_ATTR trampoline24() { auto &f = IsrTrampolines::functions[24]; if (f) f(); }
    static void IRAM_ATTR trampoline25() { auto &f = IsrTrampolines::functions[25]; if (f) f(); }
    static void IRAM_ATTR trampoline26() { auto &f = IsrTrampolines::functions[26]; if (f) f(); }
    static void IRAM_ATTR trampoline27() { auto &f = IsrTrampolines::functions[27]; if (f) f(); }
    static void IRAM_ATTR trampoline28() { auto &f = IsrTrampolines::functions[28]; if (f) f(); }
    static void IRAM_ATTR trampoline29() { auto &f = IsrTrampolines::functions[29]; if (f) f(); }
    static void IRAM_ATTR trampoline30() { auto &f = IsrTrampolines::functions[30]; if (f) f(); }
    static void IRAM_ATTR trampoline31() { auto &f = IsrTrampolines::functions[31]; if (f) f(); }
    */
};