//! FAPP end-to-end integration test.
//!
//! Tests the complete flow: therapist announces → patient queries →
//! patient reserves → therapist confirms.

use std::sync::{Arc, RwLock};
use std::time::Duration;

use quicprochat_p2p::fapp::{
    Fachrichtung, FappStore, Kostentraeger, Modalitaet, PatientCrypto, PatientEphemeralKey,
    SlotAnnounce, SlotQuery, SlotType, TherapistCrypto, TimeSlot, CAP_FAPP_PATIENT,
    CAP_FAPP_RELAY, CAP_FAPP_THERAPIST,
};
use quicprochat_p2p::fapp_router::{FappAction, FappRouter};
use quicprochat_p2p::identity::MeshIdentity;
use quicprochat_p2p::routing_table::RoutingTable;
use quicprochat_p2p::transport_manager::TransportManager;

fn future_timestamp() -> u64 {
    std::time::SystemTime::now()
        .duration_since(std::time::UNIX_EPOCH)
        .unwrap()
        .as_secs()
        + 86400 // tomorrow
}

/// Helper to create a FappRouter with given capabilities.
fn make_router(capabilities: u16) -> (FappRouter, Arc<RwLock<RoutingTable>>) {
    let routes = Arc::new(RwLock::new(RoutingTable::new(Duration::from_secs(300))));
    let transports = Arc::new(TransportManager::new());
    let store = FappStore::new();
    let router = FappRouter::new(store, Arc::clone(&routes), transports, capabilities);
    (router, routes)
}

#[test]
fn full_fapp_flow_announce_query_reserve_confirm() {
    // =========================================================================
    // Setup: Therapist, Relay, Patient
    // =========================================================================

    let therapist_id = MeshIdentity::generate();
    let therapist_crypto = TherapistCrypto::new(MeshIdentity::from_seed(therapist_id.seed_bytes()));

    // Therapist node (publishes slots)
    let (therapist_router, _) = make_router(CAP_FAPP_THERAPIST | CAP_FAPP_RELAY);

    // Relay node (caches and forwards)
    let (relay_router, _) = make_router(CAP_FAPP_RELAY);

    // Patient node (queries and reserves)
    let (patient_router, _) = make_router(CAP_FAPP_PATIENT | CAP_FAPP_RELAY);

    // =========================================================================
    // Step 1: Therapist announces slots
    // =========================================================================

    let slots = vec![
        TimeSlot {
            start_unix: future_timestamp(),
            duration_minutes: 50,
            slot_type: SlotType::Erstgespraech,
        },
        TimeSlot {
            start_unix: future_timestamp() + 3600,
            duration_minutes: 50,
            slot_type: SlotType::Probatorik,
        },
    ];

    let announce = SlotAnnounce::new(
        &therapist_id,
        vec![Fachrichtung::Verhaltenstherapie],
        vec![Modalitaet::Praxis, Modalitaet::Video],
        vec![Kostentraeger::GKV, Kostentraeger::Selbstzahler],
        "80331".into(), // Munich
        slots,
        [0xAA; 32], // Approbation hash
        1,          // sequence
    );
    let announce_id = announce.id;
    let therapist_addr = announce.therapist_address;

    // Serialize to wire format
    let announce_wire = announce.to_wire();

    // =========================================================================
    // Step 2: Relay receives and stores the announcement
    // =========================================================================

    // Simulate wire reception at relay
    let mut relay_wire = vec![0x01]; // FAPP_WIRE_ANNOUNCE tag
    relay_wire.extend_from_slice(&announce_wire);

    // Relay needs the therapist's public key to verify
    relay_router
        .register_therapist_key(therapist_addr, therapist_id.public_key())
        .expect("register key");

    let action = relay_router.handle_incoming(&relay_wire);

    // Relay should store and forward (but no routes, so just ignore forward failure)
    match action {
        FappAction::Forward { .. } | FappAction::Ignore => {
            // Expected: either forward to neighbors or ignore if no routes
        }
        other => panic!("Expected Forward or Ignore, got {:?}", other),
    }

    // =========================================================================
    // Step 3: Patient queries for therapists
    // =========================================================================

    let query = SlotQuery {
        query_id: [0x42; 16],
        fachrichtung: Some(Fachrichtung::Verhaltenstherapie),
        modalitaet: Some(Modalitaet::Video),
        kostentraeger: Some(Kostentraeger::GKV),
        plz_prefix: Some("803".into()), // Munich area
        earliest: None,
        latest: None,
        slot_type: Some(SlotType::Erstgespraech),
        max_results: 10,
    };

    // Relay processes query and returns matches
    let action = relay_router.process_slot_query(query.clone());
    let response = match action {
        FappAction::QueryResponse(r) => r,
        other => panic!("Expected QueryResponse, got {:?}", other),
    };

    assert_eq!(response.query_id, [0x42; 16]);
    assert_eq!(response.matches.len(), 1, "Should find one matching therapist");
    assert_eq!(response.matches[0].therapist_address, therapist_addr);

    // =========================================================================
    // Step 4: Patient creates and sends a reservation
    // =========================================================================

    let patient_ephemeral = PatientEphemeralKey::generate();
    let patient_pub = patient_ephemeral.public_bytes();
    let patient_crypto = PatientCrypto::new(patient_ephemeral);

    let contact_info = b"email: patient@example.com, Tel: +49 89 12345678";
    let reserve = patient_crypto
        .create_reserve(
            announce_id,
            0, // First slot (Erstgespraech)
            contact_info,
            &therapist_crypto.x25519_public(),
        )
        .expect("create reserve");

    assert_eq!(reserve.slot_announce_id, announce_id);
    assert_eq!(reserve.slot_index, 0);

    // =========================================================================
    // Step 5: Relay routes reserve to therapist
    // =========================================================================

    // Relay receives the reserve
    let reserve_wire = reserve.to_wire();
    let mut relay_reserve_wire = vec![0x04]; // FAPP_WIRE_RESERVE
    relay_reserve_wire.extend_from_slice(&reserve_wire);

    let action = relay_router.handle_incoming(&relay_reserve_wire);

    match action {
        FappAction::DeliverReserve { therapist_address, reserve: r } => {
            assert_eq!(therapist_address, therapist_addr);
            assert_eq!(r.slot_index, 0);
        }
        FappAction::Forward { .. } => {
            // Also acceptable if we're flooding to find therapist
        }
        other => panic!("Expected DeliverReserve or Forward, got {:?}", other),
    }

    // =========================================================================
    // Step 6: Therapist decrypts reserve and sees contact info
    // =========================================================================

    let decrypted_contact = therapist_crypto
        .decrypt_reserve(&reserve)
        .expect("therapist decrypt");
    assert_eq!(decrypted_contact, contact_info);

    // =========================================================================
    // Step 7: Therapist creates confirmation
    // =========================================================================

    let details = b"Termin bestaetigt! Praxis: Leopoldstr. 42, 80802 Muenchen. Bitte 5 min vorher da sein.";
    let confirm = therapist_crypto
        .create_confirm(
            announce_id,
            0,
            true, // confirmed
            details,
            &patient_pub,
        )
        .expect("create confirm");

    assert!(confirm.confirmed);

    // =========================================================================
    // Step 8: Patient receives and decrypts confirmation
    // =========================================================================

    // Simulate wire reception at patient
    let confirm_wire = confirm.to_wire();
    let mut patient_confirm_wire = vec![0x05]; // FAPP_WIRE_CONFIRM
    patient_confirm_wire.extend_from_slice(&confirm_wire);

    let action = patient_router.handle_incoming(&patient_confirm_wire);

    match action {
        FappAction::DeliverConfirm { confirm: c, .. } => {
            assert!(c.confirmed);
            assert_eq!(c.slot_announce_id, announce_id);
        }
        other => panic!("Expected DeliverConfirm, got {:?}", other),
    }

    let decrypted_details = patient_crypto
        .decrypt_confirm(&confirm)
        .expect("patient decrypt");
    assert_eq!(decrypted_details, details);

    println!("=== FAPP Flow Complete ===");
    println!("Therapist announced: {:?}", hex::encode(&therapist_addr[..4]));
    println!("Patient reserved slot 0 (Erstgespraech)");
    println!("Therapist confirmed appointment");
    println!("Patient decrypted: {}", String::from_utf8_lossy(&decrypted_details));
}

#[test]
fn fapp_rejection_flow() {
    // Test the rejection case: therapist declines reservation

    let therapist_id = MeshIdentity::generate();
    let therapist_crypto = TherapistCrypto::new(MeshIdentity::from_seed(therapist_id.seed_bytes()));

    let patient_ephemeral = PatientEphemeralKey::generate();
    let patient_pub = patient_ephemeral.public_bytes();
    let patient_crypto = PatientCrypto::new(patient_ephemeral);

    // Patient reserves
    let reserve = patient_crypto
        .create_reserve(
            [0xAA; 16],
            0,
            b"patient@example.com",
            &therapist_crypto.x25519_public(),
        )
        .expect("create reserve");

    // Therapist sees it's already booked and rejects
    let rejection = therapist_crypto
        .create_confirm(
            reserve.slot_announce_id,
            reserve.slot_index,
            false, // rejected
            b"Termin leider bereits vergeben. Bitte waehlen Sie einen anderen Slot.",
            &patient_pub,
        )
        .expect("create rejection");

    assert!(!rejection.confirmed);

    // Patient decrypts rejection
    let decrypted = patient_crypto
        .decrypt_confirm(&rejection)
        .expect("decrypt rejection");

    assert!(String::from_utf8_lossy(&decrypted).contains("bereits vergeben"));
}

#[test]
fn fapp_query_filters() {
    // Test that query filters work correctly

    let (router, _) = make_router(CAP_FAPP_RELAY);

    // Add two therapists with different specializations
    let vt_therapist = MeshIdentity::generate();
    let tp_therapist = MeshIdentity::generate();

    let vt_announce = SlotAnnounce::new(
        &vt_therapist,
        vec![Fachrichtung::Verhaltenstherapie],
        vec![Modalitaet::Video],
        vec![Kostentraeger::GKV],
        "80331".into(),
        vec![TimeSlot {
            start_unix: future_timestamp(),
            duration_minutes: 50,
            slot_type: SlotType::Erstgespraech,
        }],
        [0x11; 32],
        1,
    );

    let tp_announce = SlotAnnounce::new(
        &tp_therapist,
        vec![Fachrichtung::TiefenpsychologischFundiert],
        vec![Modalitaet::Praxis],
        vec![Kostentraeger::PKV],
        "10115".into(), // Berlin
        vec![TimeSlot {
            start_unix: future_timestamp(),
            duration_minutes: 50,
            slot_type: SlotType::Therapie,
        }],
        [0x22; 32],
        1,
    );

    // Register and store both
    router.register_therapist_key(vt_announce.therapist_address, vt_therapist.public_key()).unwrap();
    router.register_therapist_key(tp_announce.therapist_address, tp_therapist.public_key()).unwrap();
    router.store_announce(vt_announce.clone()).unwrap();
    router.store_announce(tp_announce.clone()).unwrap();

    // Query for VT only
    let vt_query = SlotQuery {
        query_id: [0x01; 16],
        fachrichtung: Some(Fachrichtung::Verhaltenstherapie),
        modalitaet: None,
        kostentraeger: None,
        plz_prefix: None,
        earliest: None,
        latest: None,
        slot_type: None,
        max_results: 10,
    };

    let response = match router.process_slot_query(vt_query) {
        FappAction::QueryResponse(r) => r,
        other => panic!("Expected QueryResponse, got {:?}", other),
    };

    assert_eq!(response.matches.len(), 1);
    assert_eq!(response.matches[0].therapist_address, vt_announce.therapist_address);

    // Query for TP only
    let tp_query = SlotQuery {
        query_id: [0x02; 16],
        fachrichtung: Some(Fachrichtung::TiefenpsychologischFundiert),
        modalitaet: None,
        kostentraeger: None,
        plz_prefix: None,
        earliest: None,
        latest: None,
        slot_type: None,
        max_results: 10,
    };

    let response = match router.process_slot_query(tp_query) {
        FappAction::QueryResponse(r) => r,
        other => panic!("Expected QueryResponse, got {:?}", other),
    };

    assert_eq!(response.matches.len(), 1);
    assert_eq!(response.matches[0].therapist_address, tp_announce.therapist_address);

    // Query for Berlin (PLZ 101...)
    let berlin_query = SlotQuery {
        query_id: [0x03; 16],
        fachrichtung: None,
        modalitaet: None,
        kostentraeger: None,
        plz_prefix: Some("101".into()),
        earliest: None,
        latest: None,
        slot_type: None,
        max_results: 10,
    };

    let response = match router.process_slot_query(berlin_query) {
        FappAction::QueryResponse(r) => r,
        other => panic!("Expected QueryResponse, got {:?}", other),
    };

    assert_eq!(response.matches.len(), 1);
    assert_eq!(response.matches[0].therapist_address, tp_announce.therapist_address);
}