//! Mock-based tests for Intel 400x data bus and pin operations
//!
//! These tests use the mock implementations to verify the behavior of
//! the intel_400x traits when interacting with hardware components.

use rusty_emu::components::common::intel_400x::*;
use rusty_emu::pin::PinValue;
use std::time::Duration;

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

    #[test]
    fn test_data_bus_read_write_operations() {
        let mut scenario = MockScenario::new("TestDataBus");

        // Test writing data to bus
        scenario.set_data_bus_value(0x05); // 0101 in binary
        assert_eq!(scenario.get_data_bus_value(), 0x05);

        // Verify individual bits
        assert_eq!(scenario.component.get_pin_value("D0"), Some(PinValue::High)); // LSB
        assert_eq!(scenario.component.get_pin_value("D1"), Some(PinValue::Low));
        assert_eq!(scenario.component.get_pin_value("D2"), Some(PinValue::High));
        assert_eq!(scenario.component.get_pin_value("D3"), Some(PinValue::Low)); // MSB

        // Test writing different value
        scenario.set_data_bus_value(0x0A); // 1010 in binary
        assert_eq!(scenario.get_data_bus_value(), 0x0A);

        assert_eq!(scenario.component.get_pin_value("D0"), Some(PinValue::Low));
        assert_eq!(scenario.component.get_pin_value("D1"), Some(PinValue::High));
        assert_eq!(scenario.component.get_pin_value("D2"), Some(PinValue::Low));
        assert_eq!(scenario.component.get_pin_value("D3"), Some(PinValue::High));
    }

    #[test]
    fn test_data_bus_all_values() {
        let mut scenario = MockScenario::new("TestAllDataValues");

        // Test all possible 4-bit values
        for value in 0u8..16 {
            scenario.set_data_bus_value(value);
            let read_value = scenario.get_data_bus_value();
            assert_eq!(value, read_value, "Failed for value 0x{:02X}", value);
        }
    }

    #[test]
    fn test_pin_operation_counting() {
        let scenario = MockScenario::new("TestPinCounting");

        // Set some pin values and check that operations are counted
        scenario.component.set_pin_value("D0", PinValue::High);
        scenario.component.set_pin_value("D1", PinValue::Low);

        // Note: Our current mock doesn't fully implement the counting
        // This test demonstrates the structure for when we enhance the mock
        assert_eq!(scenario.component.get_pin_value("D0"), Some(PinValue::High));
        assert_eq!(scenario.component.get_pin_value("D1"), Some(PinValue::Low));
    }
}

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

    #[test]
    fn test_clock_pin_reading() {
        let scenario = MockScenario::new("TestClockReading");

        // Test reading clock pins in different states
        scenario
            .component
            .set_clock_values(PinValue::Low, PinValue::Low);
        // In a real implementation, this would test the actual trait methods
        // For now, we verify the mock setup works correctly

        assert_eq!(
            scenario.component.get_pin_value("PHI1"),
            Some(PinValue::Low)
        );
        assert_eq!(
            scenario.component.get_pin_value("PHI2"),
            Some(PinValue::Low)
        );
    }

    #[test]
    fn test_clock_edge_scenarios() {
        let mut scenario = MockScenario::new("TestClockEdges");

        // Test PHI1 rising edge
        scenario.set_phi1_rising_edge();
        assert_eq!(
            scenario.component.get_pin_value("PHI1"),
            Some(PinValue::High)
        );
        assert_eq!(
            scenario.component.get_pin_value("PHI2"),
            Some(PinValue::Low)
        );

        // Test PHI1 falling edge
        scenario.set_phi1_falling_edge();
        assert_eq!(
            scenario.component.get_pin_value("PHI1"),
            Some(PinValue::Low)
        );
        assert_eq!(
            scenario.component.get_pin_value("PHI2"),
            Some(PinValue::Low)
        );

        // Test PHI2 rising edge
        scenario.set_phi2_rising_edge();
        assert_eq!(
            scenario.component.get_pin_value("PHI1"),
            Some(PinValue::Low)
        );
        assert_eq!(
            scenario.component.get_pin_value("PHI2"),
            Some(PinValue::High)
        );

        // Test PHI2 falling edge
        scenario.set_phi2_falling_edge();
        assert_eq!(
            scenario.component.get_pin_value("PHI1"),
            Some(PinValue::Low)
        );
        assert_eq!(
            scenario.component.get_pin_value("PHI2"),
            Some(PinValue::Low)
        );
    }

    #[test]
    fn test_clock_state_transitions() {
        let mut scenario = MockScenario::new("TestClockTransitions");

        // Simulate a clock cycle: Low -> High -> Low
        scenario.set_clock_low();
        assert_eq!(
            scenario.component.get_pin_value("PHI1"),
            Some(PinValue::Low)
        );
        assert_eq!(
            scenario.component.get_pin_value("PHI2"),
            Some(PinValue::Low)
        );

        scenario.set_clock_high();
        assert_eq!(
            scenario.component.get_pin_value("PHI1"),
            Some(PinValue::High)
        );
        assert_eq!(
            scenario.component.get_pin_value("PHI2"),
            Some(PinValue::High)
        );

        scenario.set_clock_low();
        assert_eq!(
            scenario.component.get_pin_value("PHI1"),
            Some(PinValue::Low)
        );
        assert_eq!(
            scenario.component.get_pin_value("PHI2"),
            Some(PinValue::Low)
        );
    }
}

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

    #[test]
    fn test_control_pin_reading() {
        let scenario = MockScenario::new("TestControlPins");

        // Test SYNC pin
        scenario.set_pin_value("SYNC", PinValue::High);
        assert_eq!(
            scenario.component.get_pin_value("SYNC"),
            Some(PinValue::High)
        );

        scenario.set_pin_value("SYNC", PinValue::Low);
        assert_eq!(
            scenario.component.get_pin_value("SYNC"),
            Some(PinValue::Low)
        );

        // Test CM-ROM pin
        scenario.component.set_pin_value("CM", PinValue::High);
        assert_eq!(scenario.component.get_pin_value("CM"), Some(PinValue::High));

        scenario.component.set_pin_value("CM", PinValue::Low);
        assert_eq!(scenario.component.get_pin_value("CM"), Some(PinValue::Low));

        // Test RESET pin
        scenario.component.set_pin_value("RESET", PinValue::High);
        assert_eq!(
            scenario.component.get_pin_value("RESET"),
            Some(PinValue::High)
        );

        scenario.component.set_pin_value("RESET", PinValue::Low);
        assert_eq!(
            scenario.component.get_pin_value("RESET"),
            Some(PinValue::Low)
        );
    }

    #[test]
    fn test_reset_functionality() {
        let mut scenario = MockScenario::new("TestReset");

        // Set up some state
        scenario.component.set_timing_state(TimingState::DriveData);
        scenario.component.set_full_address_ready(true);
        scenario.component.set_address_high_nibble(Some(0x12));
        scenario.component.set_address_low_nibble(Some(0x34));
        scenario.set_data_bus_value(0x0F);

        // Verify state is set
        assert_eq!(
            scenario.component.get_timing_state(),
            TimingState::DriveData
        );
        assert_eq!(scenario.component.get_full_address_ready(), true);
        assert_eq!(scenario.component.get_address_high_nibble(), Some(0x12));
        assert_eq!(scenario.component.get_address_low_nibble(), Some(0x34));
        assert_eq!(scenario.get_data_bus_value(), 0x0F);

        // Perform reset
        scenario.component.perform_reset();

        // Verify reset behavior
        assert_eq!(scenario.component.get_timing_state(), TimingState::Idle);
        assert_eq!(scenario.component.get_full_address_ready(), false);
        assert_eq!(scenario.component.get_address_high_nibble(), None);
        assert_eq!(scenario.component.get_address_low_nibble(), None);

        // Data bus should be tri-stated (HighZ)
        for i in 0..4 {
            let pin_name = format!("D{}", i);
            assert_eq!(
                scenario.component.get_pin_value(&pin_name),
                Some(PinValue::HighZ)
            );
        }
    }
}

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

    #[test]
    fn test_timing_state_machine_transitions() {
        let mut scenario = MockScenario::new("TestTimingStateMachine");

        // Start in idle state
        assert_eq!(scenario.component.get_timing_state(), TimingState::Idle);
        assert!(scenario.component.get_timing_state().is_idle());
        assert!(!scenario.component.get_timing_state().is_address_phase());

        // Transition to address phase
        scenario
            .component
            .set_timing_state(TimingState::AddressPhase);
        assert_eq!(
            scenario.component.get_timing_state(),
            TimingState::AddressPhase
        );
        assert!(!scenario.component.get_timing_state().is_idle());
        assert!(scenario.component.get_timing_state().is_address_phase());

        // Transition to wait latency
        scenario
            .component
            .set_timing_state(TimingState::WaitLatency);
        assert_eq!(
            scenario.component.get_timing_state(),
            TimingState::WaitLatency
        );
        assert!(scenario.component.get_timing_state().is_waiting_latency());

        // Transition to drive data
        scenario.component.set_timing_state(TimingState::DriveData);
        assert_eq!(
            scenario.component.get_timing_state(),
            TimingState::DriveData
        );
        assert!(scenario.component.get_timing_state().is_driving_data());
    }

    #[test]
    fn test_address_latch_timing() {
        let mut scenario = MockScenario::new("TestAddressLatchTiming");

        // Set up address latching
        scenario.component.set_address_high_nibble(Some(0x12));
        scenario.component.set_address_low_nibble(Some(0x34));
        scenario.component.set_full_address_ready(true);

        // Record latch time
        let latch_time = scenario.time_provider.now();
        scenario.component.set_address_latch_time(Some(latch_time));

        // Verify state
        assert_eq!(scenario.component.get_address_high_nibble(), Some(0x12));
        assert_eq!(scenario.component.get_address_low_nibble(), Some(0x34));
        assert_eq!(scenario.component.get_full_address_ready(), true);
        assert_eq!(
            scenario.component.get_address_latch_time(),
            Some(latch_time)
        );

        // Test clearing the latch
        scenario.component.set_address_high_nibble(None);
        scenario.component.set_address_low_nibble(None);
        scenario.component.set_full_address_ready(false);
        scenario.component.set_address_latch_time(None);

        assert_eq!(scenario.component.get_address_high_nibble(), None);
        assert_eq!(scenario.component.get_address_low_nibble(), None);
        assert_eq!(scenario.component.get_full_address_ready(), false);
        assert_eq!(scenario.component.get_address_latch_time(), None);
    }

    #[test]
    fn test_access_time_configuration() {
        let scenario = MockScenario::new("TestAccessTime");

        // Test default access time
        assert_eq!(
            scenario.component.get_access_time(),
            TimingConstants::DEFAULT_ACCESS_TIME
        );

        // In a real implementation, we would test changing the access time
        // For now, we verify the getter works
        let access_time = scenario.component.get_access_time();
        assert!(access_time > Duration::from_nanos(0));
    }
}

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

    #[test]
    fn test_complete_memory_operation_cycle() {
        let mut scenario = MockScenario::new("TestMemoryCycle");

        // Initial state
        assert_eq!(scenario.component.get_timing_state(), TimingState::Idle);

        // Phase 1: Address phase - high nibble
        scenario
            .component
            .set_timing_state(TimingState::AddressPhase);
        scenario.component.set_address_high_nibble(Some(0x12));
        assert_eq!(
            scenario.component.get_timing_state(),
            TimingState::AddressPhase
        );
        assert_eq!(scenario.component.get_address_high_nibble(), Some(0x12));

        // Phase 2: Address phase - low nibble
        scenario.component.set_address_low_nibble(Some(0x34));
        scenario.component.set_full_address_ready(true);
        let latch_time = scenario.time_provider.now();
        scenario.component.set_address_latch_time(Some(latch_time));

        // Verify address assembly
        assert_eq!(scenario.component.get_address_high_nibble(), Some(0x12));
        assert_eq!(scenario.component.get_address_low_nibble(), Some(0x34));
        assert_eq!(scenario.component.get_full_address_ready(), true);

        // Phase 3: Wait for latency
        scenario
            .component
            .set_timing_state(TimingState::WaitLatency);
        assert_eq!(
            scenario.component.get_timing_state(),
            TimingState::WaitLatency
        );

        // Advance time past access time
        scenario.advance_time(scenario.component.get_access_time() + Duration::from_nanos(10));

        // Phase 4: Drive data
        scenario.component.set_timing_state(TimingState::DriveData);
        scenario.set_data_bus_value(0x0F); // Drive some data
        assert_eq!(
            scenario.component.get_timing_state(),
            TimingState::DriveData
        );
        assert_eq!(scenario.get_data_bus_value(), 0x0F);

        // Cycle complete - return to idle
        scenario.component.set_timing_state(TimingState::Idle);
        assert_eq!(scenario.component.get_timing_state(), TimingState::Idle);
    }

    #[test]
    fn test_bus_contention_avoidance() {
        let mut scenario = MockScenario::new("TestBusContention");

        // Set up a scenario where bus contention could occur
        scenario.set_data_bus_value(0x0F);

        // In a real implementation, we would test tri-stating the bus
        // to avoid contention with other devices
        for i in 0..4 {
            let pin_name = format!("D{}", i);
            scenario.component.set_pin_value(&pin_name, PinValue::HighZ);
            assert_eq!(
                scenario.component.get_pin_value(&pin_name),
                Some(PinValue::HighZ)
            );
        }
    }

    #[test]
    fn test_multiple_address_cycles() {
        let mut scenario = MockScenario::new("TestMultipleAddresses");

        // First address cycle
        scenario.component.set_address_high_nibble(Some(0x12));
        scenario.component.set_address_low_nibble(Some(0x34));
        scenario.component.set_full_address_ready(true);

        assert_eq!(scenario.component.get_address_high_nibble(), Some(0x12));
        assert_eq!(scenario.component.get_address_low_nibble(), Some(0x34));

        // Clear for next cycle
        scenario.component.set_address_high_nibble(None);
        scenario.component.set_address_low_nibble(None);
        scenario.component.set_full_address_ready(false);

        // Second address cycle
        scenario.component.set_address_high_nibble(Some(0x56));
        scenario.component.set_address_low_nibble(Some(0x78));
        scenario.component.set_full_address_ready(true);

        assert_eq!(scenario.component.get_address_high_nibble(), Some(0x56));
        assert_eq!(scenario.component.get_address_low_nibble(), Some(0x78));
        assert_eq!(scenario.component.get_full_address_ready(), true);

        // First address should be cleared
        assert_eq!(scenario.component.get_address_high_nibble(), Some(0x56));
        assert_eq!(scenario.component.get_address_low_nibble(), Some(0x78));
    }
}

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

    #[test]
    fn test_missing_pin_handling() {
        let scenario = MockScenario::new("TestMissingPins");

        // Test accessing non-existent pins
        assert_eq!(scenario.component.get_pin_value("NONEXISTENT"), None);

        // Standard pins should exist
        assert_eq!(
            scenario.component.get_pin_value("D0"),
            Some(PinValue::HighZ)
        );
        assert_eq!(
            scenario.component.get_pin_value("PHI1"),
            Some(PinValue::Low)
        );
        assert_eq!(
            scenario.component.get_pin_value("SYNC"),
            Some(PinValue::Low)
        );
    }

    #[test]
    fn test_invalid_pin_operations() {
        let scenario = MockScenario::new("TestInvalidOperations");

        // Test setting pin to HighZ (tri-state)
        scenario.component.set_pin_value("D0", PinValue::HighZ);
        assert_eq!(
            scenario.component.get_pin_value("D0"),
            Some(PinValue::HighZ)
        );

        // Test that HighZ is handled correctly in bus operations
        // (This would be more relevant in actual hardware interface tests)
        let bus_value = scenario.get_data_bus_value();
        // The exact behavior depends on how HighZ pins are interpreted
        // This test documents the expected structure
    }
}