use std::sync::Arc;

use anyhow::Context as _;
use context_server::ContextServerId;
use extension::{ContextServerConfiguration, ExtensionManifest};
use fs::Fs;
use gpui::Task;
use language::LanguageRegistry;
use project::{
    context_server_store::registry::ContextServerDescriptorRegistry,
    project_settings::ProjectSettings,
};
use settings::update_settings_file;
use ui::prelude::*;
use util::ResultExt;
use workspace::Workspace;

use crate::agent_configuration::ConfigureContextServerModal;

pub(crate) fn init(language_registry: Arc<LanguageRegistry>, fs: Arc<dyn Fs>, cx: &mut App) {
    cx.observe_new(move |_: &mut Workspace, window, cx| {
        let Some(window) = window else {
            return;
        };

        if let Some(extension_events) = extension::ExtensionEvents::try_global(cx).as_ref() {
            cx.subscribe_in(extension_events, window, {
                let language_registry = language_registry.clone();
                let fs = fs.clone();
                move |workspace, _, event, window, cx| match event {
                    extension::Event::ExtensionInstalled(manifest) => {
                        show_configure_mcp_modal(
                            language_registry.clone(),
                            manifest,
                            workspace,
                            window,
                            cx,
                        );
                    }
                    extension::Event::ExtensionUninstalled(manifest) => {
                        remove_context_server_settings(
                            manifest.context_servers.keys().cloned().collect(),
                            fs.clone(),
                            cx,
                        );
                    }
                    extension::Event::ConfigureExtensionRequested(manifest) => {
                        if !manifest.context_servers.is_empty() {
                            show_configure_mcp_modal(
                                language_registry.clone(),
                                manifest,
                                workspace,
                                window,
                                cx,
                            );
                        }
                    }
                    _ => {}
                }
            })
            .detach();
        } else {
            log::info!(
                "No extension events global found. Skipping context server configuration wizard"
            );
        }
    })
    .detach();
}

fn remove_context_server_settings(
    context_server_ids: Vec<Arc<str>>,
    fs: Arc<dyn Fs>,
    cx: &mut App,
) {
    update_settings_file::<ProjectSettings>(fs, cx, move |settings, _| {
        settings
            .context_servers
            .retain(|server_id, _| !context_server_ids.contains(server_id));
    });
}

pub enum Configuration {
    NotAvailable(ContextServerId, Option<SharedString>),
    Required(
        ContextServerId,
        Option<SharedString>,
        ContextServerConfiguration,
    ),
}

fn show_configure_mcp_modal(
    language_registry: Arc<LanguageRegistry>,
    manifest: &Arc<ExtensionManifest>,
    workspace: &mut Workspace,
    window: &mut Window,
    cx: &mut Context<'_, Workspace>,
) {
    if !window.is_window_active() {
        return;
    }

    let context_server_store = workspace.project().read(cx).context_server_store();
    let repository: Option<SharedString> = manifest.repository.as_ref().map(|s| s.clone().into());

    let registry = ContextServerDescriptorRegistry::default_global(cx).read(cx);
    let worktree_store = workspace.project().read(cx).worktree_store();
    let configuration_tasks = manifest
        .context_servers
        .keys()
        .cloned()
        .map({
            |key| {
                let Some(descriptor) = registry.context_server_descriptor(&key) else {
                    return Task::ready(Configuration::NotAvailable(
                        ContextServerId(key),
                        repository.clone(),
                    ));
                };
                cx.spawn({
                    let repository_url = repository.clone();
                    let worktree_store = worktree_store.clone();
                    async move |_, cx| {
                        let configuration = descriptor
                            .configuration(worktree_store.clone(), &cx)
                            .await
                            .context("Failed to resolve context server configuration")
                            .log_err()
                            .flatten();

                        match configuration {
                            Some(config) => Configuration::Required(
                                ContextServerId(key),
                                repository_url,
                                config,
                            ),
                            None => {
                                Configuration::NotAvailable(ContextServerId(key), repository_url)
                            }
                        }
                    }
                })
            }
        })
        .collect::<Vec<_>>();

    let jsonc_language = language_registry.language_for_name("jsonc");

    cx.spawn_in(window, async move |this, cx| {
        let configurations = futures::future::join_all(configuration_tasks).await;
        let jsonc_language = jsonc_language.await.ok();

        this.update_in(cx, |this, window, cx| {
            let workspace = cx.entity().downgrade();
            this.toggle_modal(window, cx, |window, cx| {
                ConfigureContextServerModal::new(
                    configurations.into_iter(),
                    context_server_store,
                    jsonc_language,
                    language_registry,
                    workspace,
                    window,
                    cx,
                )
            });
        })
    })
    .detach();
}