import * as vscode from 'vscode';
import { HAClient } from './haClient';
import { ADClient } from './adClient';
import { StatusBarManager } from './statusBar';
import { EntityCompletionProvider, EntityHoverProvider } from './entityProvider';
import { ErrorViewer } from './errorViewer';
import { LogExplorer } from './logExplorer';

let haClient: HAClient;
let adClient: ADClient;
let statusBar: StatusBarManager;
let errorViewer: ErrorViewer;
let outputChannel: vscode.OutputChannel;

// Non-app top-level YAML keys to ignore
const NON_APP_KEYS = new Set([
    'global_modules', 'global_dependencies', 'secrets',
    'appdaemon', 'http', 'hadashboard', 'admin', 'api', 'plugins'
]);

// ── App parsing helpers ───────────────────────────────────────────────────────

type AppEntry = { appName: string; line: number; moduleName: string };

function parseAppEntries(text: string): AppEntry[] {
    const lines = text.split('\n');
    const entries: AppEntry[] = [];
    for (let i = 0; i < lines.length; i++) {
        const m = lines[i].match(/^([a-z][a-z0-9_]*):\s*$/);
        if (!m) { continue; }
        const key = m[1];
        if (NON_APP_KEYS.has(key)) { continue; }
        let moduleName = '';
        for (let j = i + 1; j < Math.min(i + 20, lines.length); j++) {
            if (lines[j].match(/^\S/)) { break; }
            const mod = lines[j].match(/^\s+module\s*:\s*(\S+)/);
            if (mod) { moduleName = mod[1]; entries.push({ appName: key, line: i, moduleName }); break; }
        }
    }
    return entries;
}

/**
 * Parse AppDaemon app names from a YAML document.
 */
function parseAppsFromDocument(doc: vscode.TextDocument): string[] {
    if (doc.languageId !== 'yaml') { return []; }
    return parseAppEntries(doc.getText()).map(e => e.appName);
}

/**
 * Scan all YAML files in the workspace and return app definitions with location.
 */
async function findAllApps(): Promise<Array<{
    appName: string;
    uri: vscode.Uri;
    line: number;
    fileName: string;
    moduleName: string;
}>> {
    const yamlFiles = await vscode.workspace.findFiles('**/*.yaml', '**/node_modules/**');
    const results: Array<{ appName: string; uri: vscode.Uri; line: number; fileName: string; moduleName: string }> = [];

    for (const uri of yamlFiles) {
        let doc: vscode.TextDocument;
        try {
            doc = await vscode.workspace.openTextDocument(uri);
        } catch {
            continue;
        }
        const fileName = vscode.workspace.asRelativePath(uri);
        for (const entry of parseAppEntries(doc.getText())) {
            results.push({ ...entry, uri, fileName });
        }
    }
    return results;
}

// ── Virtual Sensor parsing ─────────────────────────────────────────────────

type VirtualSensorEntry = {
    sensorId: string;
    line: number;
    appName: string;
    uri: vscode.Uri;
    fileName: string;
};

type VSSectionType = 'sensors' | 'continuous_conditions' | 'averagers' | 'binary_sensors' | 'value_selectors' | 'retain_conditions' | 'default_values' | '';

function mapVirtualSensorId(key: string, section: VSSectionType): string | null {
    if (section === 'default_values') {
        return /^(binary_sensor|sensor)\.[a-z0-9_]+$/.test(key) ? key : null;
    }
    if (section === 'sensors') {
        const dot = key.indexOf('.');
        if (dot < 0) { return null; }
        const prefix = key.slice(0, dot);
        const name = key.slice(dot + 1);
        switch (prefix) {
            case 'sensor': case 'value_selector': case 'averager': return `sensor.${name}`;
            case 'binary_sensor': case 'continuous_condition': case 'retain_condition': return `binary_sensor.${name}`;
            default: return null;
        }
    }
    if (section === 'continuous_conditions' || section === 'retain_conditions' || section === 'binary_sensors') {
        return key.includes('.') ? null : `binary_sensor.${key}`;
    }
    if (section === 'averagers' || section === 'value_selectors') {
        return key.includes('.') ? null : `sensor.${key}`;
    }
    return null;
}

function parseVSSectionName(raw: string, indent: number): VSSectionType {
    const re = new RegExp(`^\\s{${indent}}(sensors|continuous_conditions|averagers|binary_sensors|value_selectors|retain_conditions|default_values):\\s*$`);
    const m = raw.match(re);
    return m ? m[1] as VSSectionType : '';
}

function parseVirtualSensorsFromText(text: string): Array<{ sensorId: string; line: number; appName: string }> {
    const lines = text.split('\n');
    const entries: Array<{ sensorId: string; line: number; appName: string }> = [];

    let currentApp = '';
    let isVSApp = false;               // module: virtualsensors
    let vsSection: VSSectionType = ''; // active sub-section in VirtualSensorsApp at indent=2
    let inVSKey = false;               // in virtual_sensors: sub-block of another app
    let nestedSection: VSSectionType = ''; // active sub-section in virtual_sensors: at indent=4

    for (let i = 0; i < lines.length; i++) {
        const raw = lines[i];
        const trimmed = raw.trimStart();
        if (!trimmed || trimmed.startsWith('#')) { continue; }
        const indent = raw.length - trimmed.length;

        if (indent === 0) {
            const m = raw.match(/^([a-z][a-z0-9_]*):\s*$/);
            currentApp = m ? m[1] : '';
            isVSApp = false; vsSection = ''; inVSKey = false; nestedSection = '';
            continue;
        }

        if (indent === 2) {
            vsSection = ''; inVSKey = false; nestedSection = '';
            if (/^\s+module:\s*virtualsensors/.test(raw)) {
                isVSApp = true;
            } else if (isVSApp) {
                vsSection = parseVSSectionName(raw, 2);
            } else {
                if (/^\s+virtual_sensors:\s*$/.test(raw)) { inVSKey = true; }
            }
            continue;
        }

        if (indent === 4) {
            nestedSection = '';
            if (isVSApp && vsSection) {
                const km = raw.match(/^\s+([a-z][a-z0-9_.]+):/);
                if (km) {
                    const sensorId = mapVirtualSensorId(km[1], vsSection);
                    if (sensorId) { entries.push({ sensorId, line: i, appName: currentApp }); }
                }
            } else if (inVSKey) {
                nestedSection = parseVSSectionName(raw, 4);
            }
            continue;
        }

        if (indent === 6 && inVSKey && nestedSection) {
            const km = raw.match(/^\s+([a-z][a-z0-9_.]+):/);
            if (km) {
                const sensorId = mapVirtualSensorId(km[1], nestedSection);
                if (sensorId) { entries.push({ sensorId, line: i, appName: currentApp }); }
            }
        }
    }
    return entries;
}

async function findAllVirtualSensors(): Promise<VirtualSensorEntry[]> {
    const yamlFiles = await vscode.workspace.findFiles('**/*.yaml', '**/node_modules/**');
    const results: VirtualSensorEntry[] = [];
    for (const uri of yamlFiles) {
        let doc: vscode.TextDocument;
        try { doc = await vscode.workspace.openTextDocument(uri); } catch { continue; }
        const fileName = vscode.workspace.asRelativePath(uri);
        for (const e of parseVirtualSensorsFromText(doc.getText())) {
            results.push({ ...e, uri, fileName });
        }
    }
    return results;
}

// ── Symbol Providers ─────────────────────────────────────────────────────────

class ADDocumentSymbolProvider implements vscode.DocumentSymbolProvider {
    provideDocumentSymbols(doc: vscode.TextDocument): vscode.DocumentSymbol[] {
        if (doc.languageId !== 'yaml') { return []; }
        return parseAppEntries(doc.getText()).map(entry => {
            const pos = new vscode.Position(entry.line, 0);
            const range = new vscode.Range(pos, pos);
            const sym = new vscode.DocumentSymbol(
                entry.appName,
                `module: ${entry.moduleName}`,
                vscode.SymbolKind.Class,
                range,
                range
            );
            return sym;
        });
    }
}

class ADWorkspaceSymbolProvider implements vscode.WorkspaceSymbolProvider {
    async provideWorkspaceSymbols(query: string): Promise<vscode.SymbolInformation[]> {
        const lq = query.toLowerCase();
        const [apps, sensors] = await Promise.all([findAllApps(), findAllVirtualSensors()]);
        const appSymbols = apps
            .filter(a => !lq || a.appName.toLowerCase().includes(lq))
            .map(a => new vscode.SymbolInformation(
                a.appName,
                vscode.SymbolKind.Class,
                `module: ${a.moduleName}`,
                new vscode.Location(a.uri, new vscode.Position(a.line, 0))
            ));
        const sensorSymbols = sensors
            .filter(s => !lq || s.sensorId.toLowerCase().includes(lq))
            .map(s => new vscode.SymbolInformation(
                s.sensorId,
                vscode.SymbolKind.Variable,
                s.appName,
                new vscode.Location(s.uri, new vscode.Position(s.line, 0))
            ));
        return [...appSymbols, ...sensorSymbols];
    }
}

class ADVirtualSensorDefinitionProvider implements vscode.DefinitionProvider {
    // Simple cache: reset on save
    private cache: VirtualSensorEntry[] | undefined;
    private cacheExpiry = 0;

    constructor(private haClient: HAClient) {}

    invalidate() { this.cache = undefined; }

    async getSensors(): Promise<VirtualSensorEntry[]> {
        const now = Date.now();
        if (this.cache && now < this.cacheExpiry) { return this.cache; }
        this.cache = await findAllVirtualSensors();
        this.cacheExpiry = now + 5000; // 5 s TTL
        return this.cache;
    }

    async provideDefinition(
        document: vscode.TextDocument,
        position: vscode.Position
    ): Promise<vscode.Definition | undefined> {
        // Match any entity ID pattern (same as hover provider)
        const wordRange = document.getWordRangeAtPosition(
            position,
            /[a-z][a-z_]*\.[a-z0-9][a-z0-9_]*/
        );
        if (!wordRange) { return undefined; }
        const entityId = document.getText(wordRange);

        // 1. Check virtual sensor index (parsed from YAML)
        const sensors = await this.getSensors();
        const vsMatch = sensors.find(s => s.sensorId === entityId);
        if (vsMatch) {
            return new vscode.Location(vsMatch.uri, new vscode.Position(vsMatch.line, 0));
        }

        // 2. Fallback: check HA entity's ad_app attribute → navigate to that app
        const entity = this.haClient.getEntity(entityId);
        const adApp = entity?.attributes?.ad_app as string | undefined;
        if (!adApp) { return undefined; }
        const apps = await findAllApps();
        const appMatch = apps.find(a => a.appName === adApp);
        if (!appMatch) { return undefined; }
        return new vscode.Location(appMatch.uri, new vscode.Position(appMatch.line, 0));
    }
}

class ADVirtualSensorHoverProvider implements vscode.HoverProvider {
    constructor(
        private haClient: HAClient,
        private defProvider: ADVirtualSensorDefinitionProvider
    ) {}

    async provideHover(
        document: vscode.TextDocument,
        position: vscode.Position
    ): Promise<vscode.Hover | undefined> {
        // Find a virtual sensor whose definition is on this exact line
        const sensors = await this.defProvider.getSensors();
        const match = sensors.find(
            s => s.uri.fsPath === document.uri.fsPath && s.line === position.line
        );
        if (!match) { return undefined; }

        const entity = this.haClient.getEntity(match.sensorId);
        if (!entity) { return undefined; }

        const md = new vscode.MarkdownString();
        md.isTrusted = true;
        const friendly = entity.attributes?.friendly_name as string | undefined;
        md.appendMarkdown(`### ${friendly || entity.entity_id}\n\n`);
        md.appendMarkdown(`| | |\n|---|---|\n`);
        md.appendMarkdown(`| **Entity** | \`${entity.entity_id}\` |\n`);
        md.appendMarkdown(`| **State** | **\`${entity.state}\`** |\n`);
        if (entity.attributes) {
            const skip = new Set(['friendly_name', 'icon', 'entity_picture', 'supported_features', 'supported_color_modes']);
            for (const [key, value] of Object.entries(entity.attributes).filter(([k]) => !skip.has(k)).slice(0, 12)) {
                const display = typeof value === 'object' ? JSON.stringify(value) : String(value);
                const truncated = display.length > 60 ? display.substring(0, 57) + '...' : display;
                md.appendMarkdown(`| ${key.replace(/\|/g, '\\|')} | \`${truncated.replace(/\|/g, '\\|')}\` |\n`);
            }
        }
        md.appendMarkdown(`\n*Last changed: ${entity.last_changed}*`);
        return new vscode.Hover(md);
    }
}

// ─────────────────────────────────────────────────────────────────────────────

function updateContextualButton(editor: vscode.TextEditor | undefined) {
    if (!editor) { statusBar.updateContextualApps([]); return; }
    const apps = parseAppsFromDocument(editor.document);
    statusBar.updateContextualApps(apps);
}

export async function activate(context: vscode.ExtensionContext) {
    // ── Output channel for debug ─────────────────────────────────────────────
    outputChannel = vscode.window.createOutputChannel('AppDaemon');
    outputChannel.appendLine('AppDaemon extension activating...');

    const config = vscode.workspace.getConfiguration('appdaemon');
    outputChannel.appendLine(`  haUrl   = ${config.get('haUrl')}`);
    outputChannel.appendLine(`  haToken = ${config.get<string>('haToken', '') ? '***set***' : '*** NOT SET ***'}`);
    outputChannel.appendLine(`  adUrl   = ${config.get('adUrl')}`);

    // ── Clients ──────────────────────────────────────────────────────────────
    haClient = new HAClient(outputChannel);
    adClient = new ADClient(outputChannel);
    errorViewer = new ErrorViewer();
    const logExplorer = new LogExplorer(context, count => statusBar.setLogErrorCount(count));
    context.subscriptions.push(logExplorer, vscode.commands.registerCommand('appdaemon.exploreLogs', () => logExplorer.show()));
    statusBar = new StatusBarManager();
    logExplorer.startPolling();

    // ── Contextual per-file restart button ───────────────────────────────────
    updateContextualButton(vscode.window.activeTextEditor);
    context.subscriptions.push(
        vscode.window.onDidChangeActiveTextEditor(updateContextualButton),
        vscode.workspace.onDidSaveTextDocument(doc => {
            if (vscode.window.activeTextEditor?.document === doc) {
                updateContextualButton(vscode.window.activeTextEditor);
            }
        })
    );

    // Initial entity load (non-blocking)
    haClient.fetchEntities().then(entities => {
        if (entities.length > 0) {
            outputChannel.appendLine(`Ready: ${entities.length} entities loaded`);
        } else {
            outputChannel.appendLine('Warning: 0 entities loaded — check haUrl and haToken settings');
        }
    });

    // Try to read current production mode from AD
    adClient.fetchProductionMode().catch(() => { /* ignore on startup */ });

    // ── Language features (YAML + Python) ────────────────────────────────────
    const selector: vscode.DocumentSelector = [
        { scheme: 'file', language: 'yaml' },
        { scheme: 'file', language: 'python' }
    ];

    const virtualSensorDefProvider = new ADVirtualSensorDefinitionProvider(haClient);

    // Invalidate definition cache on save so edits are picked up immediately
    context.subscriptions.push(
        vscode.workspace.onDidSaveTextDocument(doc => {
            if (doc.languageId === 'yaml') { virtualSensorDefProvider.invalidate(); }
        })
    );

    context.subscriptions.push(
        vscode.languages.registerCompletionItemProvider(
            selector,
            new EntityCompletionProvider(haClient),
            '.'   // trigger completion when user types a dot
        ),
        vscode.languages.registerHoverProvider(
            selector,
            new EntityHoverProvider(haClient)
        ),
        vscode.languages.registerDocumentSymbolProvider(
            { scheme: 'file', language: 'yaml' },
            new ADDocumentSymbolProvider()
        ),
        vscode.languages.registerWorkspaceSymbolProvider(
            new ADWorkspaceSymbolProvider()
        ),
        vscode.languages.registerDefinitionProvider(
            { scheme: 'file', language: 'yaml' },
            virtualSensorDefProvider
        ),
        vscode.languages.registerHoverProvider(
            { scheme: 'file', language: 'yaml' },
            new ADVirtualSensorHoverProvider(haClient, virtualSensorDefProvider)
        )
    );

    // ── Commands ─────────────────────────────────────────────────────────────

    context.subscriptions.push(
        vscode.commands.registerCommand('appdaemon.goToVirtualSensor', async () => {
            const sensors = await findAllVirtualSensors();
            if (sensors.length === 0) {
                vscode.window.showWarningMessage('AppDaemon: No virtual sensors found in workspace');
                return;
            }
            type SensorItem = vscode.QuickPickItem & { sensor: VirtualSensorEntry };
            const items: SensorItem[] = sensors.map(s => ({
                label: `$(circuit-board) ${s.sensorId}`,
                description: s.fileName,
                detail: `in ${s.appName}`,
                sensor: s
            }));
            const picked = await vscode.window.showQuickPick(items, {
                placeHolder: 'Go to virtual sensor…',
                matchOnDescription: true,
                matchOnDetail: true
            });
            if (!picked) { return; }
            const doc = await vscode.workspace.openTextDocument(picked.sensor.uri);
            const editor = await vscode.window.showTextDocument(doc);
            const pos = new vscode.Position(picked.sensor.line, 0);
            editor.selection = new vscode.Selection(pos, pos);
            editor.revealRange(new vscode.Range(pos, pos), vscode.TextEditorRevealType.InCenter);
        }),

        vscode.commands.registerCommand('appdaemon.goToApp', async (requestedName?: string) => {
            const apps = (await findAllApps()).filter(app => !requestedName || app.appName === requestedName);
            if (apps.length === 0) {
                vscode.window.showWarningMessage(requestedName
                    ? `AppDaemon: No definition found for ${requestedName}`
                    : 'AppDaemon: No app definitions found in workspace');
                return;
            }

            type AppItem = vscode.QuickPickItem & { app: typeof apps[0] };
            const items: AppItem[] = apps.map(app => ({
                label: `$(symbol-class) ${app.appName}`,
                description: app.fileName,
                detail: `Line ${app.line + 1}`,
                app
            }));

            const picked = apps.length === 1 && requestedName ? items[0] : await vscode.window.showQuickPick(items, {
                placeHolder: 'Go to AppDaemon app…',
                matchOnDescription: true,
                matchOnDetail: false
            });

            if (!picked) { return; }
            const doc = await vscode.workspace.openTextDocument(picked.app.uri);
            const editor = await vscode.window.showTextDocument(doc);
            const pos = new vscode.Position(picked.app.line, 0);
            editor.selection = new vscode.Selection(pos, pos);
            editor.revealRange(new vscode.Range(pos, pos), vscode.TextEditorRevealType.InCenter);
        }),

        vscode.commands.registerCommand('appdaemon.restartCurrentFileApps', async () => {
            const editor = vscode.window.activeTextEditor;
            if (!editor) {
                vscode.window.showWarningMessage('AppDaemon: No active file');
                return;
            }
            const apps = parseAppsFromDocument(editor.document);
            if (apps.length === 0) {
                vscode.window.showWarningMessage('AppDaemon: No app definitions found in this file');
                return;
            }
            try {
                await adClient.restartApps(apps);
                vscode.window.showInformationMessage(`AppDaemon: Restarted ${apps.join(', ')}`);
            } catch (e: unknown) {
                const msg = e instanceof Error ? e.message : String(e);
                vscode.window.showErrorMessage(`AppDaemon: Restart failed — ${msg}`);
            }
        }),

        vscode.commands.registerCommand('appdaemon.restartAD', async () => {
            try {
                await adClient.reloadApps();
                vscode.window.showInformationMessage('AppDaemon: Apps reloaded');
            } catch (e: unknown) {
                const msg = e instanceof Error ? e.message : String(e);
                vscode.window.showErrorMessage(`AppDaemon: Reload failed — ${msg}`);
            }
        }),

        vscode.commands.registerCommand('appdaemon.restartHA', async () => {
            const answer = await vscode.window.showWarningMessage(
                'Restart Home Assistant?',
                { modal: true },
                'Restart HA',
                'Restart Host'
            );
            if (!answer) {
                return;
            }
            try {
                if (answer === 'Restart Host') {
                    await haClient.restartHost();
                    vscode.window.showInformationMessage('Home Assistant: Host restart initiated');
                } else {
                    await haClient.restartHA();
                    vscode.window.showInformationMessage('Home Assistant: Restart initiated');
                }
            } catch (e: unknown) {
                const msg = e instanceof Error ? e.message : String(e);
                vscode.window.showErrorMessage(`Home Assistant: Restart failed — ${msg}`);
            }
        }),

        vscode.commands.registerCommand('appdaemon.toggleProductionMode', async () => {
            try {
                await adClient.toggleProductionMode();
                const mode = adClient.isProductionMode() ? 'ON' : 'OFF';
                vscode.window.showInformationMessage(`AppDaemon: Production mode ${mode}`);
            } catch (e: unknown) {
                const msg = e instanceof Error ? e.message : String(e);
                vscode.window.showErrorMessage(`AppDaemon: Toggle failed — ${msg}`);
            }
        }),

        vscode.commands.registerCommand('appdaemon.showErrors', () => {
            errorViewer.show();
        }),
        vscode.commands.registerCommand('appdaemon.refreshEntities', async () => {
            const entities = await haClient.fetchEntities();
            vscode.window.showInformationMessage(`AppDaemon: ${entities.length} entities loaded`);
        }),

        vscode.commands.registerCommand('appdaemon.clearErrors', () => {
            errorViewer.clearDiagnostics();
            vscode.window.showInformationMessage('AppDaemon: Error diagnostics cleared');
        })
    );

    // ── Disposables ──────────────────────────────────────────────────────────
    context.subscriptions.push(
        outputChannel,
        { dispose: () => haClient.dispose() },
        { dispose: () => adClient.dispose() },
        { dispose: () => statusBar.dispose() },
        { dispose: () => errorViewer.dispose() }
    );
}

export function deactivate() {
    haClient?.dispose();
    adClient?.dispose();
    statusBar?.dispose();
    errorViewer?.dispose();
}