use super::{fadt::Fadt, parse_rsdp, rsdp::Rsdp, sdt::SdtHeader, AcpiHandler, PhysicalMapping};
use std::boxed::Box;
/// These tests cover ideal sets of ACPI tables, which we construct on the fly. Eventually, this
/// should cover all compliant implementations, but does not guarantee we'll be able to parse a
/// particular hardware's tables, obviously.
use std::mem;
use std::ptr::NonNull;

const OEM_ID: &[u8; 6] = b"RUST  ";

/*
 * We use fake physical addresses to track what is being requested. When a particular table or
 * resource is requested, we just allocate it on the heap and return the "virtual address"
 * (a pointer onto the heap).
 */
const RSDP_ADDRESS: usize = 0x0;
const RSDT_ADDRESS: usize = 0x1;
const FADT_ADDRESS: usize = 0x2;

#[repr(C, packed)]
struct TestRsdt {
    header: SdtHeader,
    fadt: u32,
    // TODO: We should probably actually add some SDTs
}

struct TestHandler;

impl AcpiHandler for TestHandler {
    fn map_physical_region<T>(&mut self, physical_address: usize) -> PhysicalMapping<T> {
        match physical_address {
            RSDP_ADDRESS => {
                let rsdp = Box::new(Rsdp::make_testcase(
                    *b"RSD PTR ",
                    None,
                    *OEM_ID,
                    0,
                    RSDT_ADDRESS as u32,
                    0,
                    0x0,
                    None,
                    [0, 0, 0],
                ));

                PhysicalMapping {
                    physical_start: RSDP_ADDRESS,
                    virtual_start: unsafe {
                        NonNull::<T>::new_unchecked(Box::into_raw(rsdp) as *mut T)
                    },
                    region_length: mem::size_of::<Rsdp>(),
                    mapped_length: mem::size_of::<Rsdp>(),
                }
            }

            RSDT_ADDRESS => {
                let checksum = 0; // TODO: calculate real checksum
                let rsdt = Box::new(TestRsdt {
                    header: SdtHeader::make_testcase(
                        *b"RSDT",
                        mem::size_of::<TestRsdt>() as u32,
                        0,
                        checksum,
                        *OEM_ID,
                        *b"OEMRSDT ",
                        0xDEADBEEF,
                        0xDEADBEEF,
                        0xDEADBEEF,
                    ),
                    fadt: FADT_ADDRESS as u32,
                });

                PhysicalMapping {
                    physical_start: RSDT_ADDRESS,
                    virtual_start: unsafe {
                        NonNull::<T>::new_unchecked(Box::into_raw(rsdt) as *mut T)
                    },
                    region_length: mem::size_of::<TestRsdt>(),
                    mapped_length: mem::size_of::<TestRsdt>(),
                }
            }
            FADT_ADDRESS => {
                let fadt = Box::new(Fadt::make_testcase(
                    *OEM_ID,
                    *b"OEMFADT ",
                    0xDEADBEEF,
                    0xDEADBEEF,
                    0xDEADBEEF,
                ));
                PhysicalMapping {
                    physical_start: FADT_ADDRESS,
                    virtual_start: unsafe {
                        NonNull::<T>::new_unchecked(Box::into_raw(fadt) as *mut T)
                    },
                    region_length: mem::size_of::<Fadt>(),
                    mapped_length: mem::size_of::<Fadt>(),
                }
            }

            _ => panic!(
                "ACPI requested invalid physical address: {:#x}",
                physical_address
            ),
        }
    }

    fn unmap_physical_region<T>(&mut self, region: PhysicalMapping<T>) {
        match region.physical_start {
            RSDP_ADDRESS | RSDT_ADDRESS | FADT_ADDRESS => {
                let _ = unsafe { Box::from_raw(region.virtual_start.as_ptr()) };
            }

            address => panic!(
                "ACPI tried to unmap a region not created by test harness: {:#x}",
                address
            ),
        }
    }
}

#[test]
fn test_constructed_tables() {
    let mut test_handler = TestHandler;
    match parse_rsdp(&mut test_handler, RSDP_ADDRESS) {
        Ok(_) => {}

        Err(err) => {}
    }
}