import * as vscode from 'vscode';
import { TplCodeActionProvider } from './TplCodeActionProvider';
import { TplDocumentFormatter } from './TplDocumentFormatter';
import { TplCompletionProvider } from './TplCompletionProvider';
import { TplHoverProvider } from './TplHoverProvider';
import { tplBuiltIns } from './TplBuiltIns';

enum PatternPhase { None = 0, Metadata = 1, Overview = 2, Constants = 3, Triggers = 4, Mapping = 5, Removal = 6, Body = 7 }

export function activate(context: vscode.ExtensionContext) {
    const diagnosticCollection = vscode.languages.createDiagnosticCollection('tpl-scanner');
    context.subscriptions.push(diagnosticCollection);

    vscode.workspace.onDidOpenTextDocument(doc => validateTplDocument(doc, diagnosticCollection));
    vscode.workspace.onDidChangeTextDocument(event => validateTplDocument(event.document, diagnosticCollection));
    
    // NEU: Sofort reagieren, wenn in den VS Code Einstellungen etwas geändert wird
    vscode.workspace.onDidChangeConfiguration(e => {
        if (e.affectsConfiguration('tpl')) {
            for (const doc of vscode.workspace.textDocuments) {
                validateTplDocument(doc, diagnosticCollection);
            }
        }
    });

    context.subscriptions.push(vscode.languages.registerCodeActionsProvider('tpl', new TplCodeActionProvider(), { providedCodeActionKinds: [vscode.CodeActionKind.QuickFix] }));
    context.subscriptions.push(vscode.languages.registerDocumentFormattingEditProvider('tpl', new TplDocumentFormatter()));
    context.subscriptions.push(vscode.languages.registerCompletionItemProvider('tpl', new TplCompletionProvider(), '.'));
    context.subscriptions.push(vscode.languages.registerHoverProvider('tpl', new TplHoverProvider()));

    for (const doc of vscode.workspace.textDocuments) {
        validateTplDocument(doc, diagnosticCollection);
    }
}

function validateTplDocument(document: vscode.TextDocument, collection: vscode.DiagnosticCollection) {
    if (document.languageId !== 'tpl') { return; }

    const config = vscode.workspace.getConfiguration('tpl');
    const configuredTplVersion = config.get<number>('version', 23);

    const diagnostics: vscode.Diagnostic[] = [];
    const text = document.getText();
    const lines = text.split('\n');

    let tplVersion = 10;
    let hasModuleDef = false;

    let inBlock: 'none' | 'pattern' | 'table' | 'definitions' | 'enumeration' | 'configuration' = 'none';
    let currentPatternPhase: PatternPhase = PatternPhase.None;
    let inMultiLineComment = false;
    
    let inTripleDouble = false;
    let inTripleSingle = false;
    let stringNeedsSemicolon = false;

    let activePhaseName = "";
    let activePhaseLine = -1;
    let currentPatternName = "";

    // Modul-Ebene Metadaten Tracking
    let inModuleMetadata = false;
    let hasModuleMetadata = false;
    let moduleMetadataBlockLine = -1;
    let foundModuleMetadata = { origin: false, author: false, products: false, publishers: false, tree_path: false };

    const parenStack: number[] = [];
    const bracketStack: number[] = [];
    const openDefines: number[] = [];

    // State-Tracking für mehrzeilige Vergleiche / Zuweisungen
    let inConditionBlock = false;

    function addDiag(lineIdx: number, start: number, end: number, msg: string, severity: vscode.DiagnosticSeverity): vscode.Diagnostic {
        const diag = new vscode.Diagnostic(new vscode.Range(lineIdx, start, lineIdx, end), msg, severity);
        diagnostics.push(diag);
        return diag; 
    }

    // Version prüfen
    const versionMatch = text.match(/tpl\s+1\.(\d+)\s+module/);
    if (versionMatch) {
        tplVersion = parseInt(versionMatch[1], 10);
        // Warnung nur, wenn die Datei älter ist als die in den Settings eingestellte Version! Höher ist in Ordnung.
        if (tplVersion < configuredTplVersion) {
            const linesToSearch = text.substring(0, versionMatch.index! + 30).split('\n');
            const lineIdx = linesToSearch.length - 1;
            addDiag(lineIdx, 0, versionMatch[0].length, `Das Modul nutzt eine alte TPL Version (1.${tplVersion}). Aktuell in den Settings definiert ist 1.${configuredTplVersion}.`, vscode.DiagnosticSeverity.Warning);
        }
    }

    for (let i = 0; i < lines.length; i++) {
        const rawLine = lines[i];
        const line = rawLine.trim();

        const tripleDoubleCount = (rawLine.match(/"""/g) || []).length;
        const tripleSingleCount = (rawLine.match(/'''/g) || []).length;
        
        let isInternalStringLine = false;
        let justOpenedString = false;
        let isClosingString = false;

        if (inTripleDouble) {
            isInternalStringLine = true;
            if (tripleDoubleCount % 2 !== 0) { inTripleDouble = false; isClosingString = true; }
        } else if (tripleDoubleCount % 2 !== 0) {
            inTripleDouble = true; justOpenedString = true;
        }

        if (inTripleSingle) {
            isInternalStringLine = true;
            if (tripleSingleCount % 2 !== 0) { inTripleSingle = false; isClosingString = true; }
        } else if (tripleSingleCount % 2 !== 0 && !justOpenedString) {
            inTripleSingle = true; justOpenedString = true;
        }

        if (isInternalStringLine && (inTripleDouble || inTripleSingle)) { continue; }
        if (justOpenedString) { stringNeedsSemicolon = !line.startsWith('"""') && !line.startsWith("'''"); }

        const tabIndex = rawLine.indexOf('\t');
        if (tabIndex !== -1) {
            const diag = addDiag(i, tabIndex, tabIndex + 1, "Bitte Tabs durch Spaces ersetzen", vscode.DiagnosticSeverity.Warning);
            diag.code = 'invalid_tab'; 
        }

        let cleanLineForParens = line.replace(/"(?:\\.|[^"\\])*"|'(?:\\.|[^'\\])*'/g, ''); 
        const commentIdx = cleanLineForParens.indexOf('//');
        if (commentIdx !== -1) { cleanLineForParens = cleanLineForParens.substring(0, commentIdx); }

        for (let charIdx = 0; charIdx < cleanLineForParens.length; charIdx++) {
            const char = cleanLineForParens[charIdx];
            if (char === '(') { parenStack.push(i); } 
            else if (char === ')') {
                if (parenStack.length > 0) { parenStack.pop(); } 
                else { addDiag(i, 0, rawLine.length, "Unerwartete schließende Klammer ')'. Es fehlt eine öffnende Klammer.", vscode.DiagnosticSeverity.Error); }
            }
            else if (char === '[') { bracketStack.push(i); }
            else if (char === ']') {
                if (bracketStack.length > 0) { bracketStack.pop(); }
                else { addDiag(i, 0, rawLine.length, "Unerwartete schließende eckige Klammer ']'. Es fehlt eine öffnende Klammer.", vscode.DiagnosticSeverity.Error); }
            }
        }

        if (line.startsWith('//') || line.startsWith('/*')) { if (line.startsWith('/*')) {inMultiLineComment = true;} continue; }
        if (inMultiLineComment) { if (line.includes('*/')) {inMultiLineComment = false;} continue; }
        if (line.length === 0) { continue; }

        const lineWithoutStrings = rawLine.replace(/(["'])(?:(?=(\\?))\2.)*?\1/g, '""');
        if (/\b(if|elif|where)\b/.test(lineWithoutStrings)) {
            inConditionBlock = true;
        }
        if (/\b(then|do)\b/.test(lineWithoutStrings) || lineWithoutStrings.endsWith(';')) {
            inConditionBlock = false;
        }

        if (isClosingString) {
            if (stringNeedsSemicolon && !line.endsWith(';')) {
                addDiag(i, rawLine.length - 1 < 0 ? 0 : rawLine.length - 1, rawLine.length, "Fehlendes Semikolon am Ende der Zuweisung.", vscode.DiagnosticSeverity.Error);
            }
        } else {
            const noSemicolonNeeded = /^(pattern|syncmapping|traverse|table|enumeration|configuration|definitions?|define|metadata|overview|constants|triggers|mapping|removal|body|end\s+|if\s+|else|elif\s+|for\s+|while\s+|\/\/|\/\*|\*)/;
            const continuesOnNextLine = /(,|and|or|not|\+|-|\*|\/|=|:=|matches)$/i.test(line);
            
            if (!noSemicolonNeeded.test(line) && !justOpenedString && parenStack.length === 0 && bracketStack.length === 0 && inBlock !== 'enumeration' && !inConditionBlock && !continuesOnNextLine) {
                const lineToCheck = line.split('//')[0].trim();
                if (!lineToCheck.endsWith(';') && !lineToCheck.endsWith('{') && !lineToCheck.endsWith(',')) {
                    addDiag(i, rawLine.length - 1 < 0 ? 0 : rawLine.length - 1, rawLine.length, "Fehlendes Semikolon am Ende der Anweisung.", vscode.DiagnosticSeverity.Error);
                }
            }
        }

        if (!hasModuleDef) {
            if (line.startsWith('tpl ')) { hasModuleDef = true; } 
            else { addDiag(i, 0, rawLine.length, "Jede Datei muss mit 'tpl 1.x module <name>;' beginnen.", vscode.DiagnosticSeverity.Error); hasModuleDef = true; }
        }

        if (line.startsWith('metadata') && inBlock === 'none') {
            inModuleMetadata = true;
            hasModuleMetadata = true;
            moduleMetadataBlockLine = i;
            continue;
        }

        if (inModuleMetadata) {
            if (line.match(/^origin\b/)) { foundModuleMetadata.origin = true; }
            if (line.match(/^author\b/)) { foundModuleMetadata.author = true; }
            if (line.match(/^products\b/)) { foundModuleMetadata.products = true; }
            if (line.match(/^publishers\b/)) { foundModuleMetadata.publishers = true; }
            if (line.match(/^tree_path\b/)) { foundModuleMetadata.tree_path = true; }

            if (line.startsWith('end metadata')) {
                inModuleMetadata = false;
                const missing = Object.keys(foundModuleMetadata).filter(k => !(foundModuleMetadata as any)[k]);
                if (missing.length > 0 && moduleMetadataBlockLine !== -1) {
                    const diag = addDiag(moduleMetadataBlockLine, 0, 8, `Fehlende Pflicht-Metadaten (Modul-Ebene): ${missing.join(', ')}`, vscode.DiagnosticSeverity.Error);
                    diag.code = 'missing_module_metadata'; 
                }
            }
            continue;
        }

        if (line.match(/^(pattern|syncmapping|table|definitions?|enumeration|configuration)\b/)) {
            if (!hasModuleMetadata && inBlock === 'none') {
                addDiag(i, 0, line.length, "Ein 'metadata' Block auf Modul-Ebene ist Pflicht, bevor andere Blöcke definiert werden.", vscode.DiagnosticSeverity.Error);
            }
        }

        if (line.startsWith('definitions ') || line.startsWith('definition ')) {
            if (inBlock !== 'none') { addDiag(i, 0, line.length, "Ein Definitions-Block muss auf oberster Ebene deklariert werden.", vscode.DiagnosticSeverity.Error); }
            inBlock = 'definitions'; continue;
        }

        if (line.startsWith('define ')) { openDefines.push(i); continue; }

        if (line.startsWith('enumeration ')) {
            if (inBlock !== 'none') { addDiag(i, 0, line.length, "Eine Enumeration muss auf oberster Ebene deklariert werden.", vscode.DiagnosticSeverity.Error); }
            inBlock = 'enumeration'; continue;
        }

        if (line.startsWith('configuration ')) {
            if (inBlock !== 'none') { addDiag(i, 0, line.length, "Eine Konfiguration muss auf oberster Ebene deklariert werden.", vscode.DiagnosticSeverity.Error); }
            inBlock = 'configuration'; continue;
        }

        if (line.startsWith('pattern ') || line.startsWith('syncmapping ')) {
            if (inBlock !== 'none') { addDiag(i, 0, 7, "Ein Pattern/Syncmapping kann nicht innerhalb eines anderen Blocks deklariert werden.", vscode.DiagnosticSeverity.Error); }
            inBlock = 'pattern';
            currentPatternPhase = PatternPhase.None;
            activePhaseName = "";
            activePhaseLine = -1;
            
            const nameMatch = line.match(/(pattern|syncmapping)\s+([a-zA-Z0-9_]+)\s+\d+\.\d+/);
            if (nameMatch) { currentPatternName = nameMatch[2]; } 
            else { addDiag(i, 0, rawLine.length, "Ungültige Pattern-Deklaration. Erwartet: 'pattern <Name> <Version>'", vscode.DiagnosticSeverity.Error); }
            continue;
        }

        if (line.startsWith('table ')) {
            if (inBlock !== 'none') { addDiag(i, 0, 5, "Eine Tabelle kann nicht innerhalb eines anderen Blocks deklariert werden.", vscode.DiagnosticSeverity.Error); }
            inBlock = 'table'; continue;
        }

        if (inBlock === 'pattern') {
            const checkPhase = (phaseName: string, phaseEnum: PatternPhase) => {
                if (line.startsWith(phaseName)) {
                    if (activePhaseName !== "") { addDiag(activePhaseLine, 0, activePhaseName.length, `Block '${activePhaseName}' wurde nicht mit 'end ${activePhaseName};' geschlossen.`, vscode.DiagnosticSeverity.Error); }
                    if (currentPatternPhase >= phaseEnum) { addDiag(i, 0, phaseName.length, `'${phaseName}' Block ist hier nicht erlaubt.`, vscode.DiagnosticSeverity.Error); }

                    currentPatternPhase = phaseEnum;
                    activePhaseName = phaseName;
                    activePhaseLine = i;
                }
            };

            checkPhase('metadata', PatternPhase.Metadata);
            checkPhase('overview', PatternPhase.Overview);
            checkPhase('constants', PatternPhase.Constants);
            checkPhase('triggers', PatternPhase.Triggers);
            checkPhase('mapping', PatternPhase.Mapping);
            checkPhase('removal', PatternPhase.Removal);

            if (line.startsWith('body')) {
                if (activePhaseName !== "") { addDiag(activePhaseLine, 0, activePhaseName.length, `Block '${activePhaseName}' wurde nicht mit 'end ${activePhaseName};' geschlossen.`, vscode.DiagnosticSeverity.Error); }
                activePhaseName = "body";
                activePhaseLine = i;
                
                let foundLog = false;
                for (let j = i + 1; j < lines.length; j++) {
                    const aheadLine = lines[j].trim();
                    if (aheadLine.startsWith('end pattern') || aheadLine.startsWith('end syncmapping')) { break; }
                    if (aheadLine.includes('log.debug') && aheadLine.includes(currentPatternName)) { foundLog = true; break; }
                }

                if (!foundLog) {
                    const expectedLog = `log.debug("Start pattern ${currentPatternName}");`;
                    const diag = addDiag(i, 0, rawLine.length, `Im Body fehlt das Log-Statement mit dem Pattern-Namen. Bsp: ${expectedLog}`, vscode.DiagnosticSeverity.Error);
                    diag.code = 'missing_log_start'; diag.source = expectedLog;       
                }
            }

            const closers = ['end metadata', 'end overview', 'end constants', 'end triggers', 'end mapping', 'end removal', 'end body'];
            for (const closer of closers) {
                if (line.startsWith(closer)) {
                    const phase = closer.replace('end ', '').replace(';', '').trim();
                    if (activePhaseName !== phase) { addDiag(i, 0, line.length, `Unerwartetes '${closer}'. Erwartet wurde 'end ${activePhaseName};'.`, vscode.DiagnosticSeverity.Error); } 
                    else { activePhaseName = ""; }
                }
            }
        }

        if (lineWithoutStrings.includes('=') && !lineWithoutStrings.includes(':=') && !lineWithoutStrings.includes('>=') && !lineWithoutStrings.includes('<=')) {
            if (!inConditionBlock && parenStack.length === 0 && bracketStack.length === 0 && !/\b(matches)\b/.test(lineWithoutStrings)) {
                const idx = rawLine.indexOf('=');
                if (idx !== -1) {
                    addDiag(i, idx, idx + 1, "Mögliche falsche Zuweisung. In TPL wird ':=' für Zuweisungen genutzt. (Toleriert in Vergleichen/Bedingungen)", vscode.DiagnosticSeverity.Warning);
                }
            }
        }

        if (line.startsWith('end pattern') || line.startsWith('end syncmapping')) {
            if (activePhaseName !== "") { addDiag(activePhaseLine, 0, activePhaseName.length, `Block '${activePhaseName}' wurde nicht mit 'end ${activePhaseName};' geschlossen.`, vscode.DiagnosticSeverity.Error); }
            if (inBlock !== 'pattern') { addDiag(i, 0, 11, "'end pattern' gefunden, ohne offenen Pattern-Block.", vscode.DiagnosticSeverity.Error); }
            inBlock = 'none';
        }
        else if (line.startsWith('end table') || line.startsWith('end enumeration') || line.startsWith('end configuration')) {
            inBlock = 'none';
        }
        else if (line.startsWith('end definitions') || line.startsWith('end definition')) {
            if (inBlock !== 'definitions') { addDiag(i, 0, line.length, "'end definitions' gefunden, ohne offenen Definitions-Block.", vscode.DiagnosticSeverity.Error); }
            inBlock = 'none';
        }
        else if (line.startsWith('end define')) {
            if (openDefines.length > 0) { openDefines.pop(); }
            else { addDiag(i, 0, line.length, "'end define' gefunden, ohne offenes 'define'.", vscode.DiagnosticSeverity.Error); }
        }
    }

    for (const unclosedLine of parenStack) { addDiag(unclosedLine, 0, lines[unclosedLine].length, "Öffnende Klammer '(' wird nicht geschlossen!", vscode.DiagnosticSeverity.Error); }
    for (const unclosedLine of bracketStack) { addDiag(unclosedLine, 0, lines[unclosedLine].length, "Öffnende eckige Klammer '[' wird nicht geschlossen!", vscode.DiagnosticSeverity.Error); }
    for (const unclosedLine of openDefines) { addDiag(unclosedLine, 0, lines[unclosedLine].length, "Block 'define' wurde nicht mit 'end define;' geschlossen!", vscode.DiagnosticSeverity.Error); }

    collection.set(document.uri, diagnostics);
}