#pragma once

#include <AK/String.h>
#include <Kernel/PCI/Definitions.h>

class PCI::Access {
public:
    virtual void enumerate_all(Function<void(Address, ID)>&) = 0;
    virtual u8 get_interrupt_line(Address address) { return read8_field(address, PCI_INTERRUPT_LINE); }
    virtual u32 get_BAR0(Address address) { return read32_field(address, PCI_BAR0); }
    virtual u32 get_BAR1(Address address) { return read32_field(address, PCI_BAR1); }
    virtual u32 get_BAR2(Address address) { return read32_field(address, PCI_BAR2); }
    virtual u32 get_BAR3(Address address) { return read32_field(address, PCI_BAR3); }
    virtual u32 get_BAR4(Address address) { return read32_field(address, PCI_BAR4); }
    virtual u32 get_BAR5(Address address) { return read32_field(address, PCI_BAR5); }

    virtual u32 get_BAR_Space_Size(Address address, u8 bar_number)
    {
        // See PCI Spec 2.3, Page 222
        ASSERT(bar_number < 6);
        u8 field = (PCI_BAR0 + (bar_number << 2));
        u32 bar_reserved = read32_field(address, field);
        write32_field(address, field, 0xFFFFFFFF);
        u32 space_size = read32_field(address, field);
        write32_field(address, field, bar_reserved);
        space_size &= 0xfffffff0;
        space_size = (~space_size) + 1;
        return space_size;
    }

    virtual u8 get_revision_id(Address address) { return read8_field(address, PCI_REVISION_ID); }
    virtual u8 get_subclass(Address address) { return read8_field(address, PCI_SUBCLASS); }
    virtual u8 get_class(Address address) { return read8_field(address, PCI_CLASS); }
    virtual u16 get_subsystem_id(Address address) { return read16_field(address, PCI_SUBSYSTEM_ID); }
    virtual u16 get_subsystem_vendor_id(Address address) { return read16_field(address, PCI_SUBSYSTEM_VENDOR_ID); }
    virtual u16 read_type(Address address) { return (read8_field(address, PCI_CLASS) << 8u) | read8_field(address, PCI_SUBCLASS); }

    virtual void enable_bus_mastering(Address) final;
    virtual void disable_bus_mastering(Address) final;

    virtual void enumerate_bus(int type, u8 bus, Function<void(Address, ID)>&) final;
    virtual void enumerate_functions(int type, u8 bus, u8 slot, u8 function, Function<void(Address, ID)>& callback) final;
    virtual void enumerate_slot(int type, u8 bus, u8 slot, Function<void(Address, ID)>& callback) final;

    static Access& the();
    static bool is_initialized();
    virtual uint32_t get_segments_count() = 0;
    virtual uint8_t get_segment_start_bus(u32 segment) = 0;
    virtual uint8_t get_segment_end_bus(u32 segment) = 0;
    virtual String get_access_type() = 0;

protected:
    Access();

    virtual u8 read8_field(Address address, u32 field) = 0;
    virtual u16 read16_field(Address address, u32 field) = 0;
    virtual u32 read32_field(Address address, u32 field) = 0;

    virtual void write8_field(Address address, u32 field, u8 value) = 0;
    virtual void write16_field(Address address, u32 field, u16 value) = 0;
    virtual void write32_field(Address address, u32 field, u32 value) = 0;
};