use std::{
    io,
    sync::{
        Arc, Mutex,
        atomic::{AtomicUsize, Ordering},
    },
    time::Duration,
};

use axum::{Json, Router, routing::post};
use crank_core::{PlatformApiKeyScope, WorkspaceId};
use crank_observability::{
    ObservabilityConfig, OperationalIncident, RedactionLimits, ServiceIdentity,
    operational_incident_total,
};
use crank_registry::{ListInvocationLogsQuery, PublishRequest};
use serde_json::{Value, json};
use time::{OffsetDateTime, format_description::well_known::Rfc3339};
use tokio::net::TcpListener;
use tracing_subscriber::fmt::MakeWriter;

#[path = "integration/common.rs"]
mod common;

use common::*;

const CANARY_SECRET: &str = "dc08-canary-secret";

#[tokio::test]
async fn preserves_mcp_result_when_postgres_rejects_invocation_history() {
    let registry = test_registry().await;
    let upstream_calls = Arc::new(AtomicUsize::new(0));
    let upstream_base_url = spawn_counted_upstream(Arc::clone(&upstream_calls)).await;
    let operation = test_operation(&upstream_base_url, "crm_dc08");

    registry
        .create_operation(&test_workspace_id(), &operation, Some("alice"))
        .await
        .unwrap();
    registry
        .publish_operation(PublishRequest {
            workspace_id: &test_workspace_id(),
            operation_id: &operation.id,
            version: 1,
            published_at: &OffsetDateTime::parse("2026-03-26T10:00:00Z", &Rfc3339).unwrap(),
            published_by: Some("alice"),
        })
        .await
        .unwrap();
    publish_agent_for_operation(&registry, &operation, "sales-dc08").await;
    let api_key = create_platform_api_key(
        &registry,
        "sales-dc08",
        "mcp-dc08",
        &[PlatformApiKeyScope::Read, PlatformApiKeyScope::Write],
    )
    .await;
    install_history_failure_trigger(&registry).await;

    let writer = SharedLogWriter::default();
    let subscriber = crank_observability::build_subscriber(
        ObservabilityConfig::new(
            ServiceIdentity::try_new("mcp-server", "test", "test").unwrap(),
            "info",
            RedactionLimits::default(),
        ),
        writer.clone(),
    )
    .unwrap();
    tracing::subscriber::set_global_default(subscriber).unwrap();
    let base_url = spawn_mcp_server(build_test_app(
        registry.clone(),
        Duration::from_millis(0),
        Some("https://crank.example.com".to_owned()),
    ))
    .await;
    let client = reqwest::Client::new();
    let mcp_url = agent_mcp_url(&base_url, "sales-dc08");
    let session_id = initialize_session(&client, &mcp_url, &api_key).await;
    let before = operational_incident_total(OperationalIncident::InvocationHistoryLost);

    let result = post_jsonrpc_response(
        &client,
        &mcp_url,
        &api_key,
        Some(&session_id),
        Some("req_mcp_dc08"),
        json!({
            "jsonrpc": "2.0",
            "id": 3,
            "method": "tools/call",
            "params": {
                "name": "crm_dc08",
                "arguments": {
                    "email": format!("{CANARY_SECRET}@example.com")
                }
            }
        }),
    )
    .await
    .json::<Value>()
    .await
    .unwrap();

    assert_eq!(
        result["result"]["structuredContent"],
        json!({"id": "lead_123"})
    );
    assert_eq!(result["result"]["isError"], false);
    assert_eq!(upstream_calls.load(Ordering::SeqCst), 1);
    assert!(operational_incident_total(OperationalIncident::InvocationHistoryLost) > before);

    let logs = registry
        .list_invocation_logs(ListInvocationLogsQuery {
            workspace_id: &WorkspaceId::new("ws_default"),
            level: None,
            status: None,
            outcome_group: None,
            search_text: None,
            source: None,
            operation_id: Some(&operation.id),
            agent_id: None,
            created_after: None,
            created_before: None,
            cursor_created_at: None,
            cursor_id: None,
            limit: 10,
        })
        .await
        .unwrap();
    assert!(logs.is_empty());

    let output = writer.output();
    assert!(!output.contains(CANARY_SECRET));
    let incidents = output
        .lines()
        .filter_map(|line| serde_json::from_str::<Value>(line).ok())
        .filter(|event| event["event"] == "mcp.invocation_history.lost")
        .collect::<Vec<_>>();
    assert_eq!(incidents.len(), 1);
    assert_eq!(incidents[0]["request_id"], "req_mcp_dc08");
    assert_eq!(incidents[0]["fields"]["source"], "agent_tool_call");
    assert_eq!(incidents[0]["fields"]["invocation_status"], "ok");
}

async fn install_history_failure_trigger(registry: &crank_registry::PostgresRegistry) {
    sqlx::query(
        r#"
        create function fail_dc08_invocation_history() returns trigger
        language plpgsql
        as $$
        begin
            if new.request_id = 'req_mcp_dc08' then
                raise exception 'forced DC-08 invocation history failure';
            end if;
            return new;
        end;
        $$
        "#,
    )
    .execute(registry.pool())
    .await
    .unwrap();
    sqlx::query(
        r#"
        create trigger fail_dc08_invocation_history
        before insert on invocation_logs
        for each row execute function fail_dc08_invocation_history()
        "#,
    )
    .execute(registry.pool())
    .await
    .unwrap();
}

async fn spawn_counted_upstream(calls: Arc<AtomicUsize>) -> String {
    let app = Router::new().route(
        "/crm/leads",
        post(move |Json(payload): Json<Value>| {
            let calls = Arc::clone(&calls);
            async move {
                calls.fetch_add(1, Ordering::SeqCst);
                Json(json!({
                    "id": "lead_123",
                    "email": payload["email"]
                }))
            }
        }),
    );
    let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
    let address = listener.local_addr().unwrap();
    tokio::spawn(async move {
        axum::serve(listener, app).await.unwrap();
    });
    format!("http://{address}")
}

#[derive(Clone, Default)]
struct SharedLogWriter {
    buffer: Arc<Mutex<Vec<u8>>>,
}

impl SharedLogWriter {
    fn output(&self) -> String {
        String::from_utf8(self.buffer.lock().unwrap().clone()).unwrap()
    }
}

impl<'a> MakeWriter<'a> for SharedLogWriter {
    type Writer = SharedLogGuard;

    fn make_writer(&'a self) -> Self::Writer {
        SharedLogGuard {
            buffer: Arc::clone(&self.buffer),
        }
    }
}

struct SharedLogGuard {
    buffer: Arc<Mutex<Vec<u8>>>,
}

impl io::Write for SharedLogGuard {
    fn write(&mut self, bytes: &[u8]) -> io::Result<usize> {
        self.buffer.lock().unwrap().extend_from_slice(bytes);
        Ok(bytes.len())
    }

    fn flush(&mut self) -> io::Result<()> {
        Ok(())
    }
}