import * as vscode from 'vscode';
import * as lc from 'vscode-languageclient/node';
import * as ra from './lsp_ext';

import { Config } from './config';
import { createClient } from './client';
import { isRustEditor, RustEditor } from './util';
import { ServerStatusParams } from './lsp_ext';

export type Workspace =
    {
        kind: 'Workspace Folder',
        folder: vscode.Uri,
    }
    | {
        kind: 'Detached files',
        files: vscode.TextDocument[],
    };

export class Ctx {
    private constructor(
        readonly config: Config,
        private readonly extCtx: vscode.ExtensionContext,
        readonly client: lc.LanguageClient,
        readonly serverPath: string,
        readonly statusBar: vscode.StatusBarItem,
    ) {

    }

    static async create(
        config: Config,
        extCtx: vscode.ExtensionContext,
        serverPath: string,
        workspace: Workspace,
    ): Promise<Ctx> {
        const client = createClient(serverPath, workspace, config.serverExtraEnv);

        const statusBar = vscode.window.createStatusBarItem(vscode.StatusBarAlignment.Left);
        extCtx.subscriptions.push(statusBar);
        statusBar.text = "rust-analyzer";
        statusBar.tooltip = "ready";
        statusBar.show();

        const res = new Ctx(config, extCtx, client, serverPath, statusBar);

        res.pushCleanup(client.start());
        await client.onReady();
        client.onNotification(ra.serverStatus, (params) => res.setServerStatus(params));
        return res;
    }

    get activeRustEditor(): RustEditor | undefined {
        const editor = vscode.window.activeTextEditor;
        return editor && isRustEditor(editor)
            ? editor
            : undefined;
    }

    get visibleRustEditors(): RustEditor[] {
        return vscode.window.visibleTextEditors.filter(isRustEditor);
    }

    registerCommand(name: string, factory: (ctx: Ctx) => Cmd) {
        const fullName = `rust-analyzer.${name}`;
        const cmd = factory(this);
        const d = vscode.commands.registerCommand(fullName, cmd);
        this.pushCleanup(d);
    }

    get globalState(): vscode.Memento {
        return this.extCtx.globalState;
    }

    get subscriptions(): Disposable[] {
        return this.extCtx.subscriptions;
    }

    setServerStatus(status: ServerStatusParams) {
        this.statusBar.tooltip = status.message ?? "Ready";
        let icon = "";
        switch (status.health) {
            case "ok":
                this.statusBar.color = undefined;
                break;
            case "warning":
                this.statusBar.tooltip += "\nClick to reload.";
                this.statusBar.command = "rust-analyzer.reloadWorkspace";
                this.statusBar.color = new vscode.ThemeColor("notificationsWarningIcon.foreground");
                icon = "$(warning) ";
                break;
            case "error":
                this.statusBar.tooltip += "\nClick to reload.";
                this.statusBar.command = "rust-analyzer.reloadWorkspace";
                this.statusBar.color = new vscode.ThemeColor("notificationsErrorIcon.foreground");
                icon = "$(error) ";
                break;
        }
        if (!status.quiescent) icon = "$(sync~spin) ";
        this.statusBar.text = `${icon} rust-analyzer`;
    }

    pushCleanup(d: Disposable) {
        this.extCtx.subscriptions.push(d);
    }
}

export interface Disposable {
    dispose(): void;
}
export type Cmd = (...args: any[]) => unknown;