// Pattern Performance Benchmarks
// Comprehensive benchmark suite for all documented TDD patterns

use criterion::{black_box, criterion_group, criterion_main, BenchmarkId, Criterion, Throughput};
use std::time::Duration;

// ============================================================================
// 1. COMPILATION ERROR FIX PATTERN BENCHMARKS
// ============================================================================

mod error_fix_patterns {
    use super::*;

    /// Simulates E0277 trait bound error fix pattern
    /// Target: <50ms latency
    fn e0277_fix_pattern() {
        // Simulate adding Clone trait bound
        trait NeedsClone: Clone {}

        #[derive(Clone)]
        struct FixedType {
            value: i32,
        }

        impl NeedsClone for FixedType {}

        let instance = FixedType { value: 42 };
        let _cloned = instance.clone();
    }

    /// Simulates E0308 type mismatch error fix pattern
    /// Target: <50ms latency
    fn e0308_fix_pattern() {
        // Simulate type conversion
        fn expects_string(_s: String) {}

        let s = "hello";
        expects_string(s.to_string());
    }

    /// Simulates E0283 type annotation error fix pattern
    /// Target: <50ms latency
    fn e0283_fix_pattern() {
        // Simulate explicit type annotation
        let _result: Result<i32, ()> = Ok(42);
    }

    /// Simulates E0599 method not found error fix pattern
    /// Target: <50ms latency
    fn e0599_fix_pattern() {
        // Simulate trait import and method call
        trait HasMethod {
            fn method(&self) -> i32;
        }

        struct Type;
        impl HasMethod for Type {
            fn method(&self) -> i32 {
                42
            }
        }

        let instance = Type;
        let _result = instance.method();
    }

    pub fn benchmark_error_fixes(c: &mut Criterion) {
        let mut group = c.benchmark_group("error_fix_patterns");
        group.measurement_time(Duration::from_secs(10));

        group.bench_function("E0277_trait_bound_fix", |b| b.iter(|| e0277_fix_pattern()));

        group.bench_function("E0308_type_mismatch_fix", |b| {
            b.iter(|| e0308_fix_pattern())
        });

        group.bench_function("E0283_type_annotation_fix", |b| {
            b.iter(|| e0283_fix_pattern())
        });

        group.bench_function("E0599_method_not_found_fix", |b| {
            b.iter(|| e0599_fix_pattern())
        });

        // Batch error fixing - linear time complexity
        group.bench_function("batch_error_fixing", |b| {
            b.iter(|| {
                for _ in 0..100 {
                    e0277_fix_pattern();
                    e0308_fix_pattern();
                    e0283_fix_pattern();
                    e0599_fix_pattern();
                }
            })
        });

        group.finish();
    }
}

// ============================================================================
// 2. POKA-YOKE PATTERN BENCHMARKS
// ============================================================================

mod poka_yoke_patterns {
    use super::*;

    /// Type-safe builder pattern
    /// Target: <1μs per field
    #[derive(Default)]
    struct TypeSafeBuilder {
        field1: Option<i32>,
        field2: Option<String>,
        field3: Option<bool>,
    }

    impl TypeSafeBuilder {
        fn new() -> Self {
            Self::default()
        }

        fn field1(mut self, value: i32) -> Self {
            self.field1 = Some(value);
            self
        }

        fn field2(mut self, value: String) -> Self {
            self.field2 = Some(value);
            self
        }

        fn field3(mut self, value: bool) -> Self {
            self.field3 = Some(value);
            self
        }

        fn build(self) -> Result<Built, &'static str> {
            Ok(Built {
                field1: self.field1.ok_or("field1 required")?,
                field2: self.field2.ok_or("field2 required")?,
                field3: self.field3.ok_or("field3 required")?,
            })
        }
    }

    struct Built {
        field1: i32,
        field2: String,
        field3: bool,
    }

    /// Phantom type state machine
    /// Target: Zero runtime cost
    mod phantom_types {
        use std::marker::PhantomData;

        struct Empty;
        struct Configured;

        struct StateMachine<State> {
            value: i32,
            _state: PhantomData<State>,
        }

        impl StateMachine<Empty> {
            fn new() -> Self {
                Self {
                    value: 0,
                    _state: PhantomData,
                }
            }

            fn configure(self, value: i32) -> StateMachine<Configured> {
                StateMachine {
                    value,
                    _state: PhantomData,
                }
            }
        }

        impl StateMachine<Configured> {
            fn execute(&self) -> i32 {
                self.value * 2
            }
        }

        pub fn run_state_machine() -> i32 {
            let sm = StateMachine::<Empty>::new();
            let configured = sm.configure(42);
            configured.execute()
        }
    }

    /// Trait bound method resolution
    /// Target: <1μs
    trait Validator {
        fn validate(&self) -> bool;
    }

    impl Validator for i32 {
        fn validate(&self) -> bool {
            *self > 0
        }
    }

    fn validate_with_trait_bound<T: Validator>(value: &T) -> bool {
        value.validate()
    }

    /// Zero-copy pattern
    /// Target: <1% allocation increase
    fn zero_copy_pattern(data: &[u8]) -> &[u8] {
        // Return slice without copying
        &data[0..data.len().min(10)]
    }

    pub fn benchmark_poka_yoke(c: &mut Criterion) {
        let mut group = c.benchmark_group("poka_yoke_patterns");

        // Type-safe builder
        group.bench_function("type_safe_builder_construction", |b| {
            b.iter(|| {
                let _built = TypeSafeBuilder::new()
                    .field1(black_box(42))
                    .field2(black_box("hello".to_string()))
                    .field3(black_box(true))
                    .build()
                    .unwrap();
            })
        });

        // Phantom type validation (should be zero runtime cost)
        group.bench_function("phantom_type_validation", |b| {
            b.iter(|| {
                let _result = phantom_types::run_state_machine();
            })
        });

        // Trait bound method resolution
        group.bench_function("trait_bound_resolution", |b| {
            b.iter(|| {
                let value = black_box(42);
                let _valid = validate_with_trait_bound(&value);
            })
        });

        // Zero-copy overhead
        let data = vec![0u8; 1024];
        group.bench_function("zero_copy_overhead", |b| {
            b.iter(|| {
                let _slice = zero_copy_pattern(black_box(&data));
            })
        });

        group.finish();
    }
}

// ============================================================================
// 3. LEAN TEST REFACTORING BENCHMARKS
// ============================================================================

mod lean_test_patterns {
    use super::*;

    /// Test fixture builder
    /// Target: <5ms creation
    struct TestFixture {
        data: Vec<i32>,
        config: String,
        state: bool,
    }

    struct TestFixtureBuilder {
        data: Vec<i32>,
        config: String,
        state: bool,
    }

    impl TestFixtureBuilder {
        fn new() -> Self {
            Self {
                data: Vec::new(),
                config: String::new(),
                state: false,
            }
        }

        fn with_data(mut self, data: Vec<i32>) -> Self {
            self.data = data;
            self
        }

        fn with_config(mut self, config: String) -> Self {
            self.config = config;
            self
        }

        fn with_state(mut self, state: bool) -> Self {
            self.state = state;
            self
        }

        fn build(self) -> TestFixture {
            TestFixture {
                data: self.data,
                config: self.config,
                state: self.state,
            }
        }
    }

    /// Setup/teardown pattern
    /// Target: <10ms
    fn setup() -> Vec<i32> {
        vec![1, 2, 3, 4, 5]
    }

    fn teardown(_data: Vec<i32>) {
        // Cleanup
    }

    fn run_test(data: &[i32]) -> i32 {
        data.iter().sum()
    }

    /// State isolation verification
    fn isolated_test() -> i32 {
        let data = setup();
        let result = run_test(&data);
        teardown(data);
        result
    }

    pub fn benchmark_lean_tests(c: &mut Criterion) {
        let mut group = c.benchmark_group("lean_test_patterns");

        // Fixture creation
        group.bench_function("test_fixture_builder_creation", |b| {
            b.iter(|| {
                let _fixture = TestFixtureBuilder::new()
                    .with_data(vec![1, 2, 3])
                    .with_config("test".to_string())
                    .with_state(true)
                    .build();
            })
        });

        // Setup/teardown
        group.bench_function("setup_teardown", |b| {
            b.iter(|| {
                let data = setup();
                let _result = run_test(&data);
                teardown(data);
            })
        });

        // State isolation
        group.bench_function("state_isolation", |b| {
            b.iter(|| {
                let _result = isolated_test();
            })
        });

        // Full test execution
        group.bench_function("test_execution_100ms_target", |b| {
            b.iter(|| {
                for _ in 0..10 {
                    let _result = isolated_test();
                }
            })
        });

        group.finish();
    }
}

// ============================================================================
// 4. GEMBA WALK SCORING BENCHMARKS
// ============================================================================

mod gemba_walk_patterns {
    use super::*;

    #[derive(Debug, Clone)]
    struct TestScore {
        coverage: f64,
        clarity: f64,
        isolation: f64,
        speed: f64,
    }

    impl TestScore {
        /// Target: <1ms per test
        fn calculate(test_name: &str, execution_time_ms: u64, has_assertions: bool) -> Self {
            let coverage = if has_assertions { 0.8 } else { 0.3 };
            let clarity = (test_name.len() as f64 / 100.0).min(1.0);
            let isolation = if execution_time_ms < 100 { 1.0 } else { 0.5 };
            let speed = 1.0 - (execution_time_ms as f64 / 1000.0).min(1.0);

            Self {
                coverage,
                clarity,
                isolation,
                speed,
            }
        }

        fn total(&self) -> f64 {
            (self.coverage + self.clarity + self.isolation + self.speed) / 4.0
        }
    }

    /// Observability tracking
    /// Target: <5% overhead
    struct ObservabilityTracker {
        events: Vec<String>,
    }

    impl ObservabilityTracker {
        fn new() -> Self {
            Self { events: Vec::new() }
        }

        fn track(&mut self, event: String) {
            self.events.push(event);
        }

        fn report(&self) -> String {
            format!("Tracked {} events", self.events.len())
        }
    }

    /// Quality report generation
    /// Target: <100ms for 100 tests
    fn generate_quality_report(scores: &[TestScore]) -> String {
        let avg_score = scores.iter().map(|s| s.total()).sum::<f64>() / scores.len() as f64;
        format!("Average quality score: {:.2}", avg_score)
    }

    pub fn benchmark_gemba_walk(c: &mut Criterion) {
        let mut group = c.benchmark_group("gemba_walk_patterns");

        // Score calculation
        group.bench_function("score_calculation", |b| {
            b.iter(|| {
                let _score = TestScore::calculate(
                    black_box("test_comprehensive_validation"),
                    black_box(50),
                    black_box(true),
                );
            })
        });

        // Observability tracking overhead
        group.bench_function("observability_tracking_overhead", |b| {
            b.iter(|| {
                let mut tracker = ObservabilityTracker::new();
                for i in 0..100 {
                    tracker.track(format!("event_{}", i));
                }
                let _report = tracker.report();
            })
        });

        // Quality report generation
        let scores: Vec<TestScore> = (0..100)
            .map(|i| TestScore::calculate(&format!("test_{}", i), 50, true))
            .collect();

        group.bench_function("quality_report_generation_100_tests", |b| {
            b.iter(|| {
                let _report = generate_quality_report(black_box(&scores));
            })
        });

        group.finish();
    }
}

// ============================================================================
// 5. FMEA CALCULATION BENCHMARKS
// ============================================================================

mod fmea_patterns {
    use super::*;

    #[derive(Debug, Clone)]
    struct ErrorRPN {
        severity: u32,
        occurrence: u32,
        detection: u32,
    }

    impl ErrorRPN {
        /// Target: <1μs per error
        fn calculate(&self) -> u32 {
            self.severity * self.occurrence * self.detection
        }

        fn priority(&self) -> &'static str {
            match self.calculate() {
                0..=100 => "Low",
                101..=500 => "Medium",
                _ => "High",
            }
        }
    }

    /// Distribution analysis
    /// Target: <100μs for 252 errors
    fn analyze_distribution(errors: &[ErrorRPN]) -> (u32, u32, u32) {
        let mut low = 0;
        let mut medium = 0;
        let mut high = 0;

        for error in errors {
            match error.priority() {
                "Low" => low += 1,
                "Medium" => medium += 1,
                "High" => high += 1,
                _ => {}
            }
        }

        (low, medium, high)
    }

    /// Priority ranking
    /// Target: <1ms for all errors
    fn rank_by_priority(errors: &[ErrorRPN]) -> Vec<(usize, u32)> {
        let mut ranked: Vec<(usize, u32)> = errors
            .iter()
            .enumerate()
            .map(|(i, e)| (i, e.calculate()))
            .collect();

        ranked.sort_by(|a, b| b.1.cmp(&a.1));
        ranked
    }

    pub fn benchmark_fmea(c: &mut Criterion) {
        let mut group = c.benchmark_group("fmea_patterns");

        // RPN calculation
        group.bench_function("rpn_calculation", |b| {
            b.iter(|| {
                let error = ErrorRPN {
                    severity: black_box(8),
                    occurrence: black_box(6),
                    detection: black_box(4),
                };
                let _rpn = error.calculate();
            })
        });

        // Distribution analysis for 252 errors
        let errors: Vec<ErrorRPN> = (0..252)
            .map(|i| ErrorRPN {
                severity: (i % 10) + 1,
                occurrence: ((i / 10) % 10) + 1,
                detection: ((i / 100) % 10) + 1,
            })
            .collect();

        group.throughput(Throughput::Elements(252));
        group.bench_function("distribution_analysis_252_errors", |b| {
            b.iter(|| {
                let _distribution = analyze_distribution(black_box(&errors));
            })
        });

        // Priority ranking
        group.bench_function("priority_ranking_all_errors", |b| {
            b.iter(|| {
                let _ranked = rank_by_priority(black_box(&errors));
            })
        });

        group.finish();
    }
}

// ============================================================================
// BENCHMARK GROUPS
// ============================================================================

criterion_group!(
    benches,
    error_fix_patterns::benchmark_error_fixes,
    poka_yoke_patterns::benchmark_poka_yoke,
    lean_test_patterns::benchmark_lean_tests,
    gemba_walk_patterns::benchmark_gemba_walk,
    fmea_patterns::benchmark_fmea,
);

criterion_main!(benches);
