//! Milestone 4: trust gating, rate limiting, event streaming, and
//! mdns-based auto-sync between trusted daemons.

mod support;

use std::path::Path;
use std::str::FromStr;
use std::time::{Duration, Instant};

use varde_proto::{MaterializeMode, PinPolicy, Request, ResponseData};

fn add_file(client: &mut support::Client, path: &Path) -> String {
    let reply = client.request(&Request::Add {
        path: path.display().to_string(),
        recursive: false,
    });
    assert!(reply.ok, "add failed: {:?}", reply.error);
    match reply.data {
        Some(ResponseData::Added { hash, .. }) => hash,
        other => panic!("unexpected add reply: {other:?}"),
    }
}

fn pin(client: &mut support::Client, hash: &str, open_lan: bool) {
    let reply = client.request(&Request::Pin {
        hash: hash.to_string(),
        policy: PinPolicy { open_lan },
    });
    assert!(reply.ok, "pin failed: {:?}", reply.error);
}

fn export_ticket(client: &mut support::Client, hash: &str) -> String {
    let reply = client.request(&Request::TicketExport {
        hash: hash.to_string(),
    });
    assert!(reply.ok, "ticket export failed: {:?}", reply.error);
    match reply.data {
        Some(ResponseData::Ticket { ticket }) => ticket,
        other => panic!("unexpected ticket reply: {other:?}"),
    }
}

fn import_ticket(client: &mut support::Client, ticket: &str) {
    let reply = client.request(&Request::TicketImport {
        ticket: ticket.to_string(),
        pin_policy: PinPolicy::default(),
    });
    assert!(reply.ok, "ticket import failed: {:?}", reply.error);
}

fn node_id(client: &mut support::Client) -> String {
    let reply = client.request(&Request::Status { hash: None });
    match reply.data {
        Some(ResponseData::Status(s)) => s.node_id.expect("daemon has a node id"),
        other => panic!("unexpected status reply: {other:?}"),
    }
}

fn is_complete(socket: &Path, hash: &str) -> bool {
    let mut client = support::Client::connect(socket);
    let reply = client.request(&Request::Status {
        hash: Some(hash.to_string()),
    });
    matches!(
        reply.data,
        Some(ResponseData::HashStatus(s)) if s.complete
    )
}

fn wait_complete(socket: &Path, hash: &str, timeout: Duration) -> bool {
    let deadline = Instant::now() + timeout;
    while Instant::now() < deadline {
        if is_complete(socket, hash) {
            return true;
        }
        std::thread::sleep(Duration::from_millis(100));
    }
    false
}

/// Re-target a ticket at another hash on the same provider: what an
/// attacker who learned a hash out of band would hand to their daemon.
fn forge_ticket(real_ticket: &str, target_hash: &str) -> String {
    let ticket = iroh_blobs::ticket::BlobTicket::from_str(real_ticket).unwrap();
    let hash = iroh_blobs::Hash::from_str(target_hash).unwrap();
    iroh_blobs::ticket::BlobTicket::new(
        ticket.node_addr().clone(),
        hash,
        iroh_blobs::BlobFormat::Raw,
    )
    .unwrap()
    .to_string()
}

#[test]
fn trust_gates_serving_per_hash() {
    let provider = support::spawn_daemon();
    let fetcher_dir = tempfile::tempdir().unwrap();
    let fetcher = support::spawn_daemon_at(fetcher_dir.path());
    let mut provider_client = support::Client::connect(&provider.socket);
    let mut fetcher_client = support::Client::connect(&fetcher.socket);
    let dir = tempfile::tempdir().unwrap();

    // `shared` is deliberately published via ticket; `private` is pinned
    // but never shared.
    std::fs::write(dir.path().join("shared.bin"), vec![1u8; 300_000]).unwrap();
    std::fs::write(dir.path().join("private.bin"), vec![2u8; 300_000]).unwrap();
    let shared = add_file(&mut provider_client, &dir.path().join("shared.bin"));
    let private = add_file(&mut provider_client, &dir.path().join("private.bin"));
    pin(&mut provider_client, &shared, false);
    pin(&mut provider_client, &private, false);

    let ticket = export_ticket(&mut provider_client, &shared);

    // The exported content transfers to the untrusted fetcher.
    import_ticket(&mut fetcher_client, &ticket);
    assert!(
        wait_complete(&fetcher.socket, &shared, Duration::from_secs(60)),
        "exported content must be fetchable without trust"
    );

    // A forged ticket for the never-shared hash must not: the provider
    // answers "not found" to untrusted peers.
    let forged = forge_ticket(&ticket, &private);
    import_ticket(&mut fetcher_client, &forged);
    std::thread::sleep(Duration::from_secs(5));
    assert!(
        !is_complete(&fetcher.socket, &private),
        "unshared content leaked to an untrusted peer"
    );

    // Once the provider trusts the fetcher, the same request succeeds.
    // Trust is evaluated when a connection is accepted, so restart the
    // fetcher (same store, same identity) to shed the connection that
    // was established while untrusted.
    let fetcher_id = node_id(&mut fetcher_client);
    let reply = provider_client.request(&Request::PeerTrust {
        node_id: fetcher_id,
    });
    assert!(reply.ok, "peer trust failed: {:?}", reply.error);
    drop(fetcher);
    let fetcher = support::spawn_daemon_at(fetcher_dir.path());
    let mut fetcher_client = support::Client::connect(&fetcher.socket);
    import_ticket(&mut fetcher_client, &forged);
    assert!(
        wait_complete(&fetcher.socket, &private, Duration::from_secs(60)),
        "trusted peer should be served everything"
    );
}

#[test]
fn upload_rate_limit_is_enforced() {
    let dir = tempfile::tempdir().unwrap();
    // 256 KiB/s upload cap on the provider.
    let provider = support::spawn_daemon_with_env(dir.path(), &[("VARDE_MAX_UPLOAD", "262144")]);
    let fetcher = support::spawn_daemon();
    let mut provider_client = support::Client::connect(&provider.socket);
    let mut fetcher_client = support::Client::connect(&fetcher.socket);

    let payload = vec![7u8; 1_000_000];
    let src = dir.path().join("capped.bin");
    std::fs::write(&src, &payload).unwrap();
    let hash = add_file(&mut provider_client, &src);
    pin(&mut provider_client, &hash, false);
    let ticket = export_ticket(&mut provider_client, &hash);

    let start = Instant::now();
    import_ticket(&mut fetcher_client, &ticket);
    assert!(
        wait_complete(&fetcher.socket, &hash, Duration::from_secs(120)),
        "capped fetch never completed"
    );
    let elapsed = start.elapsed();
    // 1 MB at 256 KiB/s is ~4 s minus one 256 KiB burst: ~3 s. Anything
    // under 1.5 s means the limiter did nothing (uncapped localhost
    // moves this in well under 200 ms).
    assert!(
        elapsed >= Duration::from_millis(1500),
        "1 MB fetch finished in {elapsed:?} despite 256 KiB/s upload cap"
    );
}

#[test]
fn subscribe_streams_progress_and_completion() {
    let provider = support::spawn_daemon();
    let fetcher = support::spawn_daemon();
    let mut provider_client = support::Client::connect(&provider.socket);
    let mut fetcher_client = support::Client::connect(&fetcher.socket);
    let dir = tempfile::tempdir().unwrap();

    let src = dir.path().join("watched.bin");
    std::fs::write(&src, vec![5u8; 2_000_000]).unwrap();
    let hash = add_file(&mut provider_client, &src);
    pin(&mut provider_client, &hash, false);
    let ticket = export_ticket(&mut provider_client, &hash);

    // Subscribe on the fetcher before starting the transfer.
    let mut events = support::Client::connect(&fetcher.socket);
    let ack = events.request(&Request::Subscribe {});
    assert!(ack.ok);
    events.set_read_timeout(Duration::from_secs(60));

    import_ticket(&mut fetcher_client, &ticket);

    let mut saw_progress = false;
    let mut saw_complete = false;
    while let Some(line) = events.read_event_line() {
        let event: serde_json::Value = serde_json::from_str(&line).expect("event is JSON");
        match event["event"].as_str() {
            Some("transfer_progress") => {
                assert_eq!(event["hash"].as_str(), Some(hash.as_str()));
                assert_eq!(event["direction"].as_str(), Some("download"));
                saw_progress = true;
            }
            Some("pin_complete") => {
                assert_eq!(event["hash"].as_str(), Some(hash.as_str()));
                saw_complete = true;
                break;
            }
            _ => {}
        }
    }
    assert!(saw_progress, "no transfer_progress event seen");
    assert!(saw_complete, "no pin_complete event seen");
}

/// Two trusted daemons with LAN discovery on: a pin that exists on one
/// side auto-syncs to the other with no ticket exchange. Requires
/// working multicast; skips (with a note) where mdns can't see the
/// sibling process.
#[test]
fn overlapping_pins_auto_sync_via_lan_discovery() {
    let dir_a = tempfile::tempdir().unwrap();
    let dir_b = tempfile::tempdir().unwrap();
    let a = support::spawn_daemon_with_env(dir_a.path(), &[("VARDE_DISCOVERY", "true")]);
    let b = support::spawn_daemon_with_env(dir_b.path(), &[("VARDE_DISCOVERY", "true")]);
    let mut client_a = support::Client::connect(&a.socket);
    let mut client_b = support::Client::connect(&b.socket);

    // Mutual trust: A serves B, B auto-fetches from A.
    let id_a = node_id(&mut client_a);
    let id_b = node_id(&mut client_b);
    assert!(client_a.request(&Request::PeerTrust { node_id: id_b }).ok);
    assert!(client_b.request(&Request::PeerTrust { node_id: id_a }).ok);

    // Content pinned on A only.
    let dir = tempfile::tempdir().unwrap();
    let src = dir.path().join("synced.bin");
    let payload = vec![9u8; 500_000];
    std::fs::write(&src, &payload).unwrap();
    let hash = add_file(&mut client_a, &src);
    pin(&mut client_a, &hash, false);

    // B pins the same hash without having the bytes.
    pin(&mut client_b, &hash, false);

    // Wait for B to see A via discovery at all.
    let deadline = Instant::now() + Duration::from_secs(30);
    let mut discovered = false;
    while Instant::now() < deadline {
        let reply = client_b.request(&Request::PeerList {});
        if let Some(ResponseData::Peers { peers }) = reply.data {
            if peers.iter().any(|p| p.connected) {
                discovered = true;
                break;
            }
        }
        std::thread::sleep(Duration::from_millis(250));
    }
    if !discovered {
        eprintln!("SKIP: mdns discovery saw no peers (multicast unavailable in this environment)");
        return;
    }

    assert!(
        wait_complete(&b.socket, &hash, Duration::from_secs(60)),
        "pinned content did not auto-sync from trusted LAN peer"
    );
    let dest = dir.path().join("synced-out.bin");
    let reply = client_b.request(&Request::Materialize {
        hash,
        dest: dest.display().to_string(),
        mode: MaterializeMode::Copy,
    });
    assert!(reply.ok, "materialize failed: {:?}", reply.error);
    assert_eq!(std::fs::read(&dest).unwrap(), payload);
}