// MCP Integration Test
// Tests the Model Context Protocol toolset integration with ADK agents
//
// The McpToolset is now fully implemented and can connect to any MCP-compliant server.
// These tests verify basic functionality with mock tools and integration patterns.

use adk_agent::LlmAgentBuilder;
use adk_core::{
    Agent, Content, InvocationContext, Part, ReadonlyContext, RunConfig, Session, State, Tool,
    ToolContext,
};
use adk_model::GeminiModel;
use async_trait::async_trait;
use futures::StreamExt;
use serde_json::{Value, json};
use std::collections::HashMap;
use std::env;
use std::sync::Arc;

struct MockSession;
impl Session for MockSession {
    fn id(&self) -> &str {
        "mcp-session"
    }
    fn app_name(&self) -> &str {
        "mcp-app"
    }
    fn user_id(&self) -> &str {
        "mcp-user"
    }
    fn state(&self) -> &dyn State {
        &MockState
    }
    fn conversation_history(&self) -> Vec<adk_core::Content> {
        Vec::new()
    }
}

struct MockState;
impl State for MockState {
    fn get(&self, _key: &str) -> Option<Value> {
        None
    }
    fn set(&mut self, _key: String, _value: Value) {}
    fn all(&self) -> HashMap<String, Value> {
        HashMap::new()
    }
}

struct MockContext {
    session: MockSession,
    user_content: Content,
}

impl MockContext {
    fn new(text: &str) -> Self {
        Self {
            session: MockSession,
            user_content: Content {
                role: "user".to_string(),
                parts: vec![Part::Text { text: text.to_string() }],
            },
        }
    }
}

#[async_trait]
impl ReadonlyContext for MockContext {
    fn invocation_id(&self) -> &str {
        "mcp-inv"
    }
    fn agent_name(&self) -> &str {
        "mcp-agent"
    }
    fn user_id(&self) -> &str {
        "mcp-user"
    }
    fn app_name(&self) -> &str {
        "mcp-app"
    }
    fn session_id(&self) -> &str {
        "mcp-session"
    }
    fn branch(&self) -> &str {
        "main"
    }
    fn user_content(&self) -> &Content {
        &self.user_content
    }
}

#[async_trait]
impl adk_core::CallbackContext for MockContext {
    fn artifacts(&self) -> Option<Arc<dyn adk_core::Artifacts>> {
        None
    }
}

#[async_trait]
impl InvocationContext for MockContext {
    fn agent(&self) -> Arc<dyn Agent> {
        unimplemented!()
    }
    fn memory(&self) -> Option<Arc<dyn adk_core::Memory>> {
        None
    }
    fn session(&self) -> &dyn Session {
        &self.session
    }
    fn run_config(&self) -> &RunConfig {
        unimplemented!()
    }
    fn end_invocation(&self) {}
    fn ended(&self) -> bool {
        false
    }
}

// Mock MCP Tool - simulates an MCP-provided tool
struct McpFileTool;

#[async_trait]
impl Tool for McpFileTool {
    fn name(&self) -> &str {
        "mcp_read_file"
    }
    fn description(&self) -> &str {
        "Read file content via MCP"
    }
    fn parameters_schema(&self) -> Option<Value> {
        Some(json!({
            "type": "object",
            "properties": {
                "path": {
                    "type": "string",
                    "description": "File path to read"
                }
            },
            "required": ["path"]
        }))
    }
    fn response_schema(&self) -> Option<Value> {
        None
    }

    async fn execute(&self, _ctx: Arc<dyn ToolContext>, args: Value) -> adk_core::Result<Value> {
        let path = args.get("path").and_then(|v| v.as_str()).unwrap_or("unknown");

        // Simulate MCP file read
        Ok(json!({
            "content": format!("Mock content of file: {}", path),
            "size": 1024,
            "mcp_source": "filesystem"
        }))
    }
}

#[tokio::test]
#[ignore] // Requires GEMINI_API_KEY - run with: cargo test --ignored
async fn test_mcp_tool_integration() {
    dotenvy::dotenv().ok();
    let api_key = env::var("GEMINI_API_KEY").expect("GEMINI_API_KEY must be set");

    let model = Arc::new(GeminiModel::new(api_key, "gemini-1.5-flash").unwrap());
    let mcp_tool = Arc::new(McpFileTool);

    let agent = LlmAgentBuilder::new("mcp-agent")
        .description("Agent with MCP tools")
        .model(model)
        .instruction("You can read files using the mcp_read_file tool.")
        .tool(mcp_tool)
        .build()
        .unwrap();

    let ctx = Arc::new(MockContext::new("Read the file /tmp/test.txt"));
    let mut stream = agent.run(ctx).await.unwrap();

    let mut received_response = false;
    while let Some(result) = stream.next().await {
        if let Ok(event) = result {
            if let Some(_content) = event.llm_response.content {
                received_response = true;
            }
        }
    }

    assert!(received_response, "Should have received a response with MCP tool");
}

#[tokio::test]
#[ignore = "Full MCP implementation pending"]
async fn test_mcp_server_connection() {
    // TODO: Implement when MCP server is available
    // This would test:
    // - MCP server discovery
    // - Tool registration from MCP server
    // - Dynamic tool invocation
    // - MCP protocol error handling
}

#[tokio::test]
#[ignore = "Full MCP implementation pending"]
async fn test_mcp_resource_access() {
    // TODO: Implement when MCP resources are available
    // This would test:
    // - MCP resource listing
    // - Resource content retrieval
    // - Resource updates
    // - Resource permissions
}
