#pragma once

#include "acpi/acpi.h"
#include "memory/pointer.h"
#include "util/number.h"

namespace acpi {

struct fadt_flags_t {
    uint32_t wbinvd : 1;
    uint32_t wbinvd_flush : 1;
    uint32_t processor_c1 : 1;
    uint32_t p_level2_up : 1;
    uint32_t power_button : 1;
    uint32_t sleep_button : 1;
    uint32_t fixed_rtc : 1;
    uint32_t rtc_s4 : 1;
    uint32_t timer_value_extended : 1;
    uint32_t reserved : 23;
};
static_assert(sizeof(fadt_flags_t) == 4);

// Prefix of the FADT through the flags field; real tables continue past this,
// so no field after flags may be added without also handling table revisions.
struct fadt_t {
    sdt_header_t header;
    uint32_t firmware_control;
    uint32_t dsdt_address;
    uint8_t reserved;
    uint8_t preferred_pm_profile;
    uint16_t sci_interrupt;
    uint32_t smi_command_port;
    uint8_t acpi_enable;
    uint8_t acpi_disable;
    uint8_t s4bios_request;
    uint8_t pstate_control;
    uint32_t pm1a_event_block;
    uint32_t pm1b_event_block;
    uint32_t pm1a_control_block;
    uint32_t pm1b_control_block;
    uint32_t pm2_control_block;
    uint32_t pm_timer_block;
    uint32_t gpe0_block;
    uint32_t gpe1_block;
    uint8_t pm1_event_length;
    uint8_t pm1_control_length;
    uint8_t pm2_control_length;
    uint8_t pm_timer_length;
    uint8_t gpe0_block_length;
    uint8_t gpe1_block_length;
    uint8_t gpe1_base;
    uint8_t cstate_control;
    uint16_t p_level2_latency;
    uint16_t p_level3_latency;
    uint16_t flush_size;
    uint16_t flush_stride;
    uint8_t duty_offset;
    uint8_t duty_width;
    uint8_t day_alarm;
    uint8_t month_alarm;
    uint8_t century;
    uint16_t iapc_boot_architecture;
    uint8_t reserved2;
    fadt_flags_t flags;
} __attribute__((packed));
static_assert(sizeof(fadt_t) == 116);

constexpr uint64_t pm_timer_frequency_hz = 3'579'545;

struct pm_timer_duration_t {
    uint64_t pm_ticks;
};

constexpr pm_timer_duration_t pm_timer_milliseconds(uint64_t count) {
    return pm_timer_duration_t{count * pm_timer_frequency_hz / 1'000};
}

struct Fadt {
    explicit Fadt(paddr_t fadt_physical) : table(fadt_physical.access<fadt_t>()) {}
    explicit Fadt(const fadt_t* fadt_table) : table(fadt_table) {}

    bool has_pm_timer() const {
        return table->pm_timer_block != 0 && table->pm_timer_length == 4;
    }

    uint16_t pm_timer_port() const {
        return static_cast<uint16_t>(table->pm_timer_block);
    }

    bool pm_timer_is_32bit() const {
        return table->flags.timer_value_extended != 0;
    }

private:
    const fadt_t* table;
};

} // namespace acpi