//! The handshake, the method table and the protocol errors.

mod common;

use common::{ask, writable_server};
use serde_json::{Value, json};

#[test]
fn the_handshake_echoes_a_supported_protocol_version() {
    let (_vault, mut server) = writable_server("handshake");
    let reply = ask(&mut server, &json!({"jsonrpc": "2.0", "id": 1, "method": "initialize", "params": {"protocolVersion": "2025-06-18"}}).to_string());
    let result = reply.get("result").expect("a result");
    assert_eq!(result.get("protocolVersion").and_then(Value::as_str), Some("2025-06-18"));
    assert_eq!(result.get("serverInfo").and_then(|i| i.get("name")).and_then(Value::as_str), Some("notescraft"));
    assert_eq!(result.get("serverInfo").and_then(|i| i.get("version")).and_then(Value::as_str), Some(env!("CARGO_PKG_VERSION")));
    let capabilities = result.get("capabilities").expect("capabilities");
    assert!(capabilities.get("tools").is_some(), "tools are advertised");
    assert!(capabilities.get("resources").is_some(), "resources are advertised");

    let older = ask(&mut server, &json!({"jsonrpc": "2.0", "id": 2, "method": "initialize", "params": {"protocolVersion": "2024-11-05"}}).to_string());
    assert_eq!(older.get("result").and_then(|r| r.get("protocolVersion")).and_then(Value::as_str), Some("2024-11-05"));

    let unknown = ask(&mut server, &json!({"jsonrpc": "2.0", "id": 3, "method": "initialize", "params": {"protocolVersion": "1999-01-01"}}).to_string());
    assert_eq!(unknown.get("result").and_then(|r| r.get("protocolVersion")).and_then(Value::as_str), Some(notescraft_mcp::PROTOCOL_VERSION));
}

#[test]
fn notifications_get_no_reply_and_ping_answers() {
    let (_vault, mut server) = writable_server("notify");
    assert!(server.handle_line("   \n  ").is_none(), "a blank line is not a message");
    assert!(server.handle_line(&json!({"jsonrpc": "2.0", "method": "notifications/initialized"}).to_string()).is_none());
    assert!(server.handle_line("").is_none(), "a blank line is not a message");
    let pong = ask(&mut server, &json!({"jsonrpc": "2.0", "id": "ping-1", "method": "ping"}).to_string());
    assert_eq!(pong.get("id").and_then(Value::as_str), Some("ping-1"), "a string id is echoed");
    assert_eq!(pong.get("result"), Some(&json!({})));
}

#[test]
fn every_protocol_error_has_its_code() {
    let (_vault, mut server) = writable_server("errors");
    let cases = [
        ("not json at all", -32700),
        (r#"{"jsonrpc": "2.0", "id": 1, "method": "nope/there"}"#, -32601),
        (r#"{"jsonrpc": "2.0", "id": 1, "method": "tools/call", "params": {}}"#, -32602),
        (r#"{"jsonrpc": "2.0", "id": 1, "method": "tools/call", "params": {"name": 7}}"#, -32602),
        (r#"{"jsonrpc": "2.0", "id": 1, "method": "resources/read", "params": {"uri": "http://x/y"}}"#, -32602),
        ("[1, 2]", -32600),
        (r#"{"jsonrpc": "2.0", "id": [1], "method": "ping"}"#, -32600),
    ];
    for (line, code) in cases {
        let reply = ask(&mut server, line);
        assert_eq!(reply.get("error").and_then(|error| error.get("code")).and_then(Value::as_i64), Some(code), "for {line}");
        assert!(reply.get("result").is_none(), "an error reply carries no result");
    }
}

#[test]
fn a_line_over_the_cap_is_refused_without_parsing() {
    let (_vault, mut server) = writable_server("huge");
    let line = format!(r#"{{"id":1,"method":"ping","pad":"{}"}}"#, "x".repeat(notescraft_mcp::MAX_LINE_BYTES + 1));
    let reply = ask(&mut server, &line);
    assert_eq!(reply.get("error").and_then(|error| error.get("code")).and_then(Value::as_i64), Some(-32600));
}

#[test]
fn a_batch_answers_in_order_and_stops_at_the_cap() {
    let (_vault, mut server) = writable_server("batch");
    let line = json!([{"jsonrpc": "2.0", "id": 1, "method": "ping"}, {"jsonrpc": "2.0", "method": "notifications/initialized"}, {"jsonrpc": "2.0", "id": "two", "method": "ping"}]);
    let reply = ask(&mut server, &line.to_string());
    let answers = reply.as_array().expect("a batch reply is an array");
    assert_eq!(answers.len(), 2, "the notification produced no entry");
    assert_eq!(answers.first().and_then(|r| r.get("id")).and_then(Value::as_i64), Some(1));
    assert_eq!(answers.get(1).and_then(|r| r.get("id")).and_then(Value::as_str), Some("two"));

    let too_many: Vec<_> = (0..=notescraft_mcp::MAX_BATCH).map(|id| json!({"jsonrpc": "2.0", "id": id, "method": "ping"})).collect();
    let reply = ask(&mut server, &json!(too_many).to_string());
    assert_eq!(reply.get("error").and_then(|error| error.get("code")).and_then(Value::as_i64), Some(-32600));

    let empty = ask(&mut server, "[]");
    assert_eq!(empty.get("error").and_then(|error| error.get("code")).and_then(Value::as_i64), Some(-32600));
}