use std::future::Future;
use std::pin::Pin;
use std::sync::Arc;

use async_stream::try_stream;
use futures::stream::BoxStream;
use futures::StreamExt;
use tokio::sync::Mutex;

use crate::config::permission::PermissionLevel;
use crate::config::PermissionManager;
use crate::message::{Message, ToolRequest};
use crate::permission::permission_confirmation::PrincipalType;
use crate::permission::permission_judge::get_confirmation_message;
use crate::permission::Permission;
use mcp_core::{Content, ToolError};

// Type alias for ToolFutures - used in the agent loop to join all futures together
pub(crate) type ToolFuture<'a> =
    Pin<Box<dyn Future<Output = (String, Result<Vec<Content>, ToolError>)> + Send + 'a>>;
pub(crate) type ToolFuturesVec<'a> = Arc<Mutex<Vec<ToolFuture<'a>>>>;
// Type alias for extension installation results
pub(crate) type ExtensionInstallResult = (String, Result<Vec<Content>, ToolError>);
pub(crate) type ExtensionInstallResults = Arc<Mutex<Vec<ExtensionInstallResult>>>;

use crate::agents::Agent;

pub const DECLINED_RESPONSE: &str = "The user has declined to run this tool. \
    DO NOT attempt to call this tool again. \
    If there are no alternative methods to proceed, clearly explain the situation and STOP.";

pub const CHAT_MODE_TOOL_SKIPPED_RESPONSE: &str = "Let the user know the tool call was skipped in Goose chat mode. \
                                        DO NOT apologize for skipping the tool call. DO NOT say sorry. \
                                        Provide an explanation of what the tool call would do, structured as a \
                                        plan for the user. Again, DO NOT apologize. \
                                        **Example Plan:**\n \
                                        1. **Identify Task Scope** - Determine the purpose and expected outcome.\n \
                                        2. **Outline Steps** - Break down the steps.\n \
                                        If needed, adjust the explanation based on user preferences or questions.";

impl Agent {
    pub(crate) fn handle_approval_tool_requests<'a>(
        &'a self,
        tool_requests: &'a [ToolRequest],
        install_results: ExtensionInstallResults,
        tool_futures: ToolFuturesVec<'a>,
        permission_manager: &'a mut PermissionManager,
        message_tool_response: Arc<Mutex<Message>>,
    ) -> BoxStream<'a, anyhow::Result<Message>> {
        try_stream! {
            for request in tool_requests {
                if let Ok(tool_call) = request.tool_call.clone() {
                    let (principal_type, confirmation) = get_confirmation_message(&request.id.clone(), tool_call.clone());
                    yield confirmation;

                    let mut rx = self.confirmation_rx.lock().await;
                    while let Some((req_id, confirmation)) = rx.recv().await {
                        if req_id == request.id {
                            if confirmation.permission == Permission::AllowOnce || confirmation.permission == Permission::AlwaysAllow {
                                if principal_type == PrincipalType::Extension {
                                    let extension_name = tool_call.arguments.get("extension_name")
                                                    .and_then(|v| v.as_str())
                                                    .unwrap_or("")
                                                    .to_string();

                                    let mut results = install_results.lock().await;
                                    let install_result = self.enable_extension(extension_name, request.id.clone()).await;
                                    results.push(install_result);
                                } else {
                                    // Add this tool call to the futures collection
                                    let tool_future = self.dispatch_tool_call(tool_call.clone(), request.id.clone());
                                    let mut futures = tool_futures.lock().await;
                                    futures.push(Box::pin(tool_future));

                                    if confirmation.permission == Permission::AlwaysAllow {
                                        permission_manager.update_user_permission(&tool_call.name, PermissionLevel::AlwaysAllow);
                                    }
                                }
                            } else {
                                // User declined - add declined response
                                let mut response = message_tool_response.lock().await;
                                *response = response.clone().with_tool_response(
                                    request.id.clone(),
                                    Ok(vec![Content::text(DECLINED_RESPONSE)]),
                                );
                            }
                            break; // Exit the loop once the matching `req_id` is found
                        }
                    }
                }
            }
        }.boxed()
    }

    pub(crate) fn handle_frontend_tool_requests<'a>(
        &'a self,
        tool_requests: &'a [ToolRequest],
        message_tool_response: Arc<Mutex<Message>>,
    ) -> BoxStream<'a, anyhow::Result<Message>> {
        try_stream! {
            for request in tool_requests {
                if let Ok(tool_call) = request.tool_call.clone() {
                    if self.is_frontend_tool(&tool_call.name) {
                        // Send frontend tool request and wait for response
                        yield Message::assistant().with_frontend_tool_request(
                            request.id.clone(),
                            Ok(tool_call.clone())
                        );

                        if let Some((id, result)) = self.tool_result_rx.lock().await.recv().await {
                            let mut response = message_tool_response.lock().await;
                            *response = response.clone().with_tool_response(id, result);
                        }
                    }
                }
            }
        }
        .boxed()
    }
}