use rusty_emu::components::common::intel_400x::*;
use rusty_emu::pin::PinValue;
use rusty_emu::component::{BaseComponent, Component};
use std::sync::{Arc, Mutex};
use std::time::{Duration, Instant};
use std::collections::HashMap;

// Mock component for testing trait implementations
#[derive(Debug)]
struct MockComponent {
    pins: std::collections::HashMap<String, Arc<Mutex<TestPin>>>,
}

#[derive(Debug)]
struct TestPin {
    value: PinValue,
    driver: Option<(String, PinValue)>,
}

type Pin = TestPin;

impl Pin {
    fn new() -> Self {
        Self {
            value: PinValue::HighZ,
            driver: None,
        }
    }

    fn read(&self) -> PinValue {
        self.value
    }

    fn set_driver(&mut self, driver: Option<String>, value: PinValue) {
        self.driver = driver.map(|name| (name, value));
        self.value = value;
    }
}

impl MockComponent {
    fn new() -> Self {
        Self {
            pins: std::collections::HashMap::new(),
        }
    }

    fn add_pin(&mut self, name: &str, pin: Arc<Mutex<Pin>>) {
        self.pins.insert(name.to_string(), pin);
    }

    fn get_pin(&self, name: &str) -> Result<Arc<Mutex<TestPin>>, String> {
        self.pins.get(name).cloned().ok_or_else(|| format!("Pin {} not found", name))
    }
}

impl Component for MockComponent {
    fn name(&self) -> String {
        "MockComponent".to_string()
    }

    fn pins(&self) -> HashMap<String, Arc<Mutex<rusty_emu::pin::Pin>>> {
        HashMap::new()
    }

    fn get_pin(&self, name: &str) -> Result<Arc<Mutex<rusty_emu::pin::Pin>>, String> {
        // For testing, we'll return an error since we don't have real pins
        Err(format!("Mock pin not implemented for {}", name))
    }

    fn update(&mut self) {
        // No-op for mock
    }

    fn run(&mut self) {
        // No-op for mock
    }

    fn stop(&mut self) {
        // No-op for mock
    }

    fn is_running(&self) -> bool {
        false
    }
}

impl Intel400xAddressHandling for MockComponent {
    fn get_base(&self) -> &BaseComponent {
        unimplemented!("MockComponent doesn't contain BaseComponent")
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_timing_constants() {
        // Test that timing constants have expected values
        assert_eq!(TimingConstants::DEFAULT_ACCESS_TIME, Duration::from_nanos(500));
        assert_eq!(TimingConstants::FAST_ACCESS_TIME, Duration::from_nanos(200));
        assert_eq!(TimingConstants::ADDRESS_SETUP, Duration::from_nanos(100));
        assert_eq!(TimingConstants::DATA_VALID, Duration::from_nanos(200));
    }

    #[test]
    fn test_assemble_full_address() {
        let mock = MockComponent::new();

        // Create a mock trait implementation for testing
        struct TestAddressHandler {
            base: MockComponent,
        }

        impl TestAddressHandler {
            fn new() -> Self {
                Self {
                    base: MockComponent::new(),
                }
            }
        }

        impl Intel400xAddressHandling for TestAddressHandler {
            fn get_base(&self) -> &BaseComponent {
                unimplemented!("TestAddressHandler doesn't contain BaseComponent")
            }
        }

        let handler = TestAddressHandler::new();

        // Test address assembly with valid nibbles
        assert_eq!(handler.assemble_full_address(Some(0x0F), Some(0x23)), Some(0x0F23));
        assert_eq!(handler.assemble_full_address(Some(0x12), Some(0x34)), Some(0x1234));
        assert_eq!(handler.assemble_full_address(Some(0x00), Some(0x00)), Some(0x0000));
        assert_eq!(handler.assemble_full_address(Some(0xFF), Some(0xFF)), Some(0xFFFF));

        // Test with missing nibbles
        assert_eq!(handler.assemble_full_address(None, Some(0x23)), None);
        assert_eq!(handler.assemble_full_address(Some(0x0F), None), None);
        assert_eq!(handler.assemble_full_address(None, None), None);
    }

    #[test]
    fn test_timing_state_machine() {
        // Test state machine properties
        let idle_state = TimingState::Idle;
        let address_state = TimingState::AddressPhase;
        let wait_state = TimingState::WaitLatency;
        let drive_state = TimingState::DriveData;

        // Test state queries
        assert!(idle_state.is_idle());
        assert!(!idle_state.is_address_phase());
        assert!(!idle_state.is_waiting_latency());
        assert!(!idle_state.is_driving_data());

        assert!(!address_state.is_idle());
        assert!(address_state.is_address_phase());
        assert!(!address_state.is_waiting_latency());
        assert!(!address_state.is_driving_data());

        assert!(!wait_state.is_idle());
        assert!(!wait_state.is_address_phase());
        assert!(wait_state.is_waiting_latency());
        assert!(!wait_state.is_driving_data());

        assert!(!drive_state.is_idle());
        assert!(!drive_state.is_address_phase());
        assert!(!drive_state.is_waiting_latency());
        assert!(drive_state.is_driving_data());
    }

    #[test]
    fn test_memory_state_conversions() {
        // Test conversions between MemoryState and TimingState
        let mem_idle = MemoryState::Idle;
        let timing_idle: TimingState = mem_idle.into();
        assert_eq!(timing_idle, TimingState::Idle);

        let mem_address = MemoryState::AddressPhase;
        let timing_address: TimingState = mem_address.into();
        assert_eq!(timing_address, TimingState::AddressPhase);

        let mem_wait = MemoryState::WaitLatency;
        let timing_wait: TimingState = mem_wait.into();
        assert_eq!(timing_wait, TimingState::WaitLatency);

        let mem_drive = MemoryState::DriveData;
        let timing_drive: TimingState = mem_drive.into();
        assert_eq!(timing_drive, TimingState::DriveData);

        // Test reverse conversions
        let back_to_mem: MemoryState = timing_idle.into();
        assert_eq!(back_to_mem, MemoryState::Idle);
    }

    #[test]
    fn test_ram_state_conversions() {
        // Test conversions between RamState and TimingState
        let ram_idle = RamState::Idle;
        let timing_idle: TimingState = ram_idle.into();
        assert_eq!(timing_idle, TimingState::Idle);

        let ram_read = RamState::ReadData;
        let timing_drive: TimingState = ram_read.into();
        assert_eq!(timing_drive, TimingState::DriveData);

        let ram_write = RamState::WriteData;
        let timing_drive: TimingState = ram_write.into();
        assert_eq!(timing_drive, TimingState::DriveData);

        let ram_output = RamState::OutputPort;
        let timing_drive: TimingState = ram_output.into();
        assert_eq!(timing_drive, TimingState::DriveData);
    }

    #[test]
    fn test_utils_create_driver_name() {
        assert_eq!(utils::create_driver_name("COMP1", "DATA"), "COMP1_DATA");
        assert_eq!(utils::create_driver_name("MEMORY", "ADDR"), "MEMORY_ADDR");
        assert_eq!(utils::create_driver_name("CPU", "CONTROL"), "CPU_CONTROL");
    }

    #[test]
    fn test_clock_edge_detection_logic() {
        // Test edge detection logic without hardware dependencies
        // PHI1: Low -> High (rising edge)
        assert!(PinValue::High == PinValue::High && PinValue::Low == PinValue::Low);

        // PHI1: High -> Low (falling edge)
        assert!(PinValue::Low == PinValue::Low && PinValue::High == PinValue::High);

        // PHI2: Low -> High (rising edge)
        assert!(PinValue::High == PinValue::High && PinValue::Low == PinValue::Low);

        // PHI2: High -> Low (falling edge)
        assert!(PinValue::Low == PinValue::Low && PinValue::High == PinValue::High);

        // No edge cases
        assert!(PinValue::High == PinValue::High && PinValue::High == PinValue::Low);
        assert!(PinValue::Low == PinValue::Low && PinValue::Low == PinValue::High);
    }

    #[test]
    fn test_data_bus_bit_operations() {
        // Test bit manipulation for data bus operations
        let test_values = vec![
            (0x00, [false, false, false, false]),
            (0x01, [true, false, false, false]),
            (0x02, [false, true, false, false]),
            (0x04, [false, false, true, false]),
            (0x08, [false, false, false, true]),
            (0x05, [true, false, true, false]),
            (0x0A, [false, true, false, true]),
            (0x0F, [true, true, true, true]),
        ];

        for (value, expected_bits) in test_values {
            // Test bit extraction (reading from bus)
            for i in 0..4 {
                let bit_value = (value >> i) & 1;
                assert_eq!(bit_value == 1, expected_bits[i as usize]);
            }

            // Test bit setting (writing to bus)
            let mut reconstructed = 0;
            for i in 0..4 {
                if expected_bits[i as usize] {
                    reconstructed |= 1 << i;
                }
            }
            assert_eq!(value, reconstructed);
        }
    }

    #[test]
    fn test_address_latching_logic() {
        // Test the address latching algorithm
        let mut high_nibble: Option<u8> = None;
        let mut low_nibble: Option<u8> = None;
        let mut full_address_ready = false;
        let mut address_latch_time: Option<Instant> = None;
        let access_time = Duration::from_nanos(100);

        // Mock address handler for testing the algorithm
        struct TestAddressHandler {
            base: MockComponent,
        }

        impl TestAddressHandler {
            fn new() -> Self {
                Self {
                    base: MockComponent::new(),
                }
            }
        }

        impl Intel400xAddressHandling for TestAddressHandler {
            fn get_base(&self) -> &BaseComponent {
                unimplemented!("TestAddressHandler doesn't contain BaseComponent")
            }
        }

        let handler = TestAddressHandler::new();

        // First cycle: high nibble
        handler.handle_address_latching(
            0x12,
            &mut high_nibble,
            &mut low_nibble,
            &mut full_address_ready,
            &mut address_latch_time,
            access_time,
        );

        assert_eq!(high_nibble, Some(0x12));
        assert_eq!(low_nibble, None);
        assert_eq!(full_address_ready, false);
        assert_eq!(address_latch_time, None);

        // Second cycle: low nibble
        handler.handle_address_latching(
            0x34,
            &mut high_nibble,
            &mut low_nibble,
            &mut full_address_ready,
            &mut address_latch_time,
            access_time,
        );

        assert_eq!(high_nibble, None); // Should be cleared
        assert_eq!(low_nibble, None);  // Should be cleared
        assert_eq!(full_address_ready, true);
        assert!(address_latch_time.is_some());

        // Verify the assembled address
        let assembled = handler.assemble_full_address(Some(0x12), Some(0x34));
        assert_eq!(assembled, Some(0x1234));
    }

    #[test]
    fn test_latency_timing_logic() {
        let access_time = Duration::from_nanos(100);

        // Test with no latch time (should return false)
        assert_eq!(
            Intel400xAddressHandling::handle_latency_wait(
                &MockComponent::new(),
                &None,
                access_time
            ),
            false
        );

        // Test with recent latch time (should return false if not enough time elapsed)
        let recent_time = Some(Instant::now());
        assert_eq!(
            Intel400xAddressHandling::handle_latency_wait(
                &MockComponent::new(),
                &recent_time,
                access_time
            ),
            false
        );

        // Note: Testing with elapsed time would require sleeping or mocking time
        // This demonstrates the logic structure is correct
    }
}