const path = require('path');
const vscode = require('vscode');
const {resolvePython, pyenvEnvironment, resolveSdkRoot} = require('./runtime');
const {projectForLaunch, isSprinterMakefile, taskLabel, makeCommand} =
    require('./build');

class SprinterAdapterFactory {
    constructor(output) {
        this.output = output;
    }

    createDebugAdapterDescriptor(session) {
        const settings = vscode.workspace.getConfiguration('sprinterDebugger');
        const folder = session.workspaceFolder || vscode.workspace.workspaceFolders?.[0];
        const configured = session.configuration.adapterPath;
        const sdk = configured ? null : resolveSdkRoot(
            settings.get('sdkRoot'), folder?.uri.fsPath);
        const adapter = configured || path.join(sdk, 'toolchain', 'sdbg_dap.py');
        const runtime = resolvePython({
            command: settings.get('pythonCommand', 'auto'),
            args: settings.get('pythonArguments', []),
            workspace: folder?.uri.fsPath,
        });
        const cwd = folder?.uri.fsPath || path.dirname(adapter);
        this.output.appendLine(`Python: ${runtime.command}`);
        this.output.appendLine(`DAP: ${adapter}`);
        const options = {cwd};
        const env = pyenvEnvironment(runtime.command, cwd);
        if (env) options.env = env;
        return new vscode.DebugAdapterExecutable(
            runtime.command, [...runtime.args, adapter], options);
    }
}

class SprinterTaskProvider {
    createTask(folder, project, definitionOverride) {
        const settings = vscode.workspace.getConfiguration('sprinterDebugger');
        const runtime = resolvePython({
            command: settings.get('pythonCommand', 'auto'),
            args: settings.get('pythonArguments', []),
            workspace: folder.uri.fsPath,
        });
        const relative = path.relative(folder.uri.fsPath, project);
        const definition = definitionOverride ||
            {type: 'sprinter', project: relative || '.'};
        const options = {cwd: project};
        const sdk = resolveSdkRoot(settings.get('sdkRoot'), folder.uri.fsPath);
        const env = {SPRINTER_ROOT: sdk, ...(
            pyenvEnvironment(runtime.command, project) ||
            pyenvEnvironment(runtime.command, folder.uri.fsPath) || {})};
        if (env) options.env = env;
        const task = new vscode.Task(
            definition, folder, taskLabel(project, folder.uri.fsPath), 'sprinter',
            new vscode.ProcessExecution(makeCommand(), [
                'SRC_DEBUG=1', `PYTHON=${runtime.command}`,
            ], options), ['$sprinter-sdcc']);
        task.group = vscode.TaskGroup.Build;
        return task;
    }

    async provideTasks() {
        const folders = vscode.workspace.workspaceFolders || [];
        const results = [];
        for (const folder of folders) {
            const files = await vscode.workspace.findFiles(
                new vscode.RelativePattern(folder, '**/Makefile'),
                '**/{third_party,mame,libc,libbgi,toolchain}/**');
            for (const file of files) {
                if (isSprinterMakefile(file.fsPath)) {
                    results.push(this.createTask(folder, path.dirname(file.fsPath)));
                }
            }
        }
        return results;
    }

    resolveTask(task) {
        const folder = task.scope?.uri ? task.scope :
            vscode.workspace.workspaceFolders?.[0];
        const project = task.definition.project;
        if (!folder || typeof project !== 'string') return undefined;
        const directory = path.resolve(folder.uri.fsPath, project);
        if (!isSprinterMakefile(path.join(directory, 'Makefile'))) return undefined;
        return this.createTask(folder, directory, task.definition);
    }
}

async function runBuildTask(task) {
    const early = [], ended = [];
    let execution, resolveResult, completed = false;
    const result = new Promise(resolve => {resolveResult = resolve;});
    function finish(code) {
        if (!completed) {
            completed = true;
            resolveResult(code);
        }
    }
    const processListener = vscode.tasks.onDidEndTaskProcess(event => {
        early.push(event);
        if (execution && event.execution === execution) finish(event.exitCode);
    });
    const endListener = vscode.tasks.onDidEndTask(event => {
        ended.push(event);
        if (execution && event.execution === execution) {
            // При отмене задачи process exit event может не появиться.
            setTimeout(() => finish(undefined), 100);
        }
    });
    try {
        execution = await vscode.tasks.executeTask(task);
        const finished = early.find(event => event.execution === execution);
        if (finished) finish(finished.exitCode);
        if (ended.some(event => event.execution === execution)) {
            setTimeout(() => finish(undefined), 100);
        }
        return await result;
    } finally {
        processListener.dispose();
        endListener.dispose();
    }
}

class SprinterConfigurationProvider {
    constructor(tasks, output) {
        this.tasks = tasks;
        this.output = output;
    }

    async resolveDebugConfiguration(folder, configuration) {
        if (configuration.type !== 'sprinter-mame' ||
            configuration.request !== 'launch' ||
            configuration.autoBuild === false || configuration.preLaunchTask) {
            return configuration;
        }
        const workspace = folder?.uri.fsPath ||
            vscode.workspace.workspaceFolders?.[0]?.uri.fsPath;
        if (!workspace) return configuration;
        const mameHome = vscode.workspace.getConfiguration('sprinterDebugger')
            .get('mameHome');
        if (!configuration.mameHome && mameHome) configuration.mameHome = mameHome;
        try {
            const project = projectForLaunch(configuration, workspace);
            if (project && isSprinterMakefile(path.join(project, 'Makefile'))) {
                const scope = folder || vscode.workspace.workspaceFolders[0];
                const task = this.tasks.createTask(scope, project);
                this.output.appendLine(`Build: ${project}`);
                const code = await runBuildTask(task);
                if (code !== 0) {
                    vscode.window.showErrorMessage(
                        `Сборка Sprinter не прошла (код ${code ?? 'отмена'}); MAME не запущен`);
                    return undefined;
                }
            }
        } catch (error) {
            vscode.window.showErrorMessage(`Sprinter Build: ${error.message}`);
            return undefined;
        }
        return configuration;
    }
}

function activate(context) {
    const output = vscode.window.createOutputChannel('Sprinter MAME Debug');
    context.subscriptions.push(output);
    context.subscriptions.push(vscode.debug.registerDebugAdapterDescriptorFactory(
        'sprinter-mame', new SprinterAdapterFactory(output)));
    const tasks = new SprinterTaskProvider();
    context.subscriptions.push(vscode.tasks.registerTaskProvider('sprinter', tasks));
    context.subscriptions.push(vscode.debug.registerDebugConfigurationProvider(
        'sprinter-mame', new SprinterConfigurationProvider(tasks, output)));
    context.subscriptions.push(vscode.commands.registerCommand('sprinter.buildActive', async () => {
        const editor = vscode.window.activeTextEditor;
        const folder = editor && vscode.workspace.getWorkspaceFolder(editor.document.uri);
        if (!editor || !folder) {
            vscode.window.showErrorMessage('Откройте C-файл проекта Sprinter');
            return;
        }
        let directory = path.dirname(editor.document.uri.fsPath);
        const root = folder.uri.fsPath;
        while (directory !== path.dirname(directory)) {
            if (isSprinterMakefile(path.join(directory, 'Makefile'))) {
                try {
                    await vscode.tasks.executeTask(tasks.createTask(folder, directory));
                } catch (error) {
                    vscode.window.showErrorMessage(`Sprinter Build: ${error.message}`);
                }
                return;
            }
            if (directory === root) break;
            directory = path.dirname(directory);
        }
        vscode.window.showErrorMessage('Не найден проект Sprinter с app.mk');
    }));
}

function deactivate() {}

module.exports = {activate, deactivate, SprinterTaskProvider,
                  SprinterConfigurationProvider, runBuildTask};