import * as vscode from "vscode";
import axios from "axios";

let VSConfig: vscode.WorkspaceConfiguration;
let apiEndpoint: string;
let apiAuthentication: string;
let apiModel: string;
let apiTemperature: number;
let numPredict: number;
let promptWindowSize: number;
let completionKeys: string;
let responsePreview: boolean | undefined;
let responsePreviewMaxTokens: number;
let responsePreviewDelay: number;
let continueInline: boolean | undefined;
let keepAlive: number | undefined;
let topP: number | undefined;

function updateVSConfig() {
    VSConfig = vscode.workspace.getConfiguration("fabelous-autocoder");
    apiEndpoint = VSConfig.get("endpoint") || "http://localhost:11434/api/generate";
    apiAuthentication = VSConfig.get("authentication") || "";
    apiModel = VSConfig.get("model") || "fabelous-coder:latest";
    numPredict = VSConfig.get("max tokens predicted") || 1000;
    promptWindowSize = VSConfig.get("prompt window size") || 2000;
    completionKeys = VSConfig.get("completion keys") || " ";
    responsePreview = VSConfig.get("response preview");
    responsePreviewMaxTokens = VSConfig.get("preview max tokens") || 50;
    responsePreviewDelay = VSConfig.get("preview delay") || 0;
    continueInline = VSConfig.get("continue inline");
    apiTemperature = VSConfig.get("temperature") || 0.7;
    keepAlive = VSConfig.get("keep alive") || 30;
    topP = VSConfig.get("top p") || 1;
}

updateVSConfig();
vscode.workspace.onDidChangeConfiguration(updateVSConfig);

function getContextLines(document: vscode.TextDocument, position: vscode.Position): string {
    const lines = [];
    const startLine = Math.max(0, position.line - 1);
    const endLine = position.line;

    for (let i = startLine; i <= endLine; i++) {
        lines.push(document.lineAt(i).text);
    }

    return lines.join("\n");
}


function createFIMPrompt(prefix: string, language: string): string {
    return `<fim_prefix>${prefix}<fim_middle><fim_suffix>${language}\n`;
}

const previewDecorationType = vscode.window.createTextEditorDecorationType({
    color: '#888888', // Grayed-out preview text
    fontStyle: 'italic',
    rangeBehavior: vscode.DecorationRangeBehavior.ClosedOpen, // Ensure proper handling of multiline decorations
});

async function autocompleteCommand(textEditor: vscode.TextEditor, cancellationToken?: vscode.CancellationToken) {
    const document = textEditor.document;
    const position = textEditor.selection.active;

    const context = getContextLines(document, position);
    const fimPrompt = createFIMPrompt(context, document.languageId);

    vscode.window.withProgress(
        {
            location: vscode.ProgressLocation.Notification,
            title: "Fabelous Autocoder",
            cancellable: true,
        },
        async (progress, progressCancellationToken) => {
            try {
                progress.report({ message: "Starting model..." });
    
                let axiosCancelPost: () => void;
                const axiosCancelToken = new axios.CancelToken((c) => {
                    axiosCancelPost = () => {
                        c("Autocompletion request terminated by user cancel");
                    };
                    if (cancellationToken) cancellationToken.onCancellationRequested(axiosCancelPost);
                    progressCancellationToken.onCancellationRequested(axiosCancelPost);
                    vscode.workspace.onDidCloseTextDocument(axiosCancelPost);
                });
    
                const response = await axios.post(apiEndpoint, {
                    model: apiModel,
                    prompt: fimPrompt,
                    stream: false,
                    raw: true,
                    options: {
                        num_predict: numPredict,
                        temperature: apiTemperature,
                        stop: ["<fim_suffix>", "```"]
                    }
                }, {
                    cancelToken: axiosCancelToken,
                    headers: {
                        'Authorization': apiAuthentication
                    }
                });
    
                progress.report({ message: "Generating..." });
    
                let completionText = response.data.response;
                completionText = completionText.replace(/<fim_middle>|<fim_suffix>|<fim_prefix>/g, '').trim();
    
                // Split the completion text by new lines
                const lines = completionText.split('\n');
    
                // Create a decoration for each line of the response
                const previewRanges = lines.map((line: string, idx: number) => {
                    const linePos = new vscode.Position(position.line + idx, 0);
                    const range = new vscode.Range(linePos, linePos); // Set range at the start of each new line
                    return {
                        range,
                        renderOptions: {
                            before: {
                                contentText: line,
                                color: '#888888',
                                fontStyle: 'italic',
                            }
                        }
                    };
                });
    
                // Apply the decorations for multiline preview
                textEditor.setDecorations(previewDecorationType, previewRanges);
    
                let completionInserted = false; // Flag to track insertion
    
                const disposable = vscode.workspace.onDidChangeTextDocument(async (event) => {
                    if (event.document.uri.toString() === document.uri.toString()) {
                        const change = event.contentChanges[0];
    
                        // Handle Backspace to decline the preview
                        if (change && change.text === '' && change.rangeLength === 1) {
                            textEditor.setDecorations(previewDecorationType, []); // Remove preview decorations
                            disposable.dispose();
                        }
    
                        // Handle Ctrl + Enter (or Cmd + Enter on macOS) to accept the preview
                        const isCtrlOrCmdPressed = event.contentChanges.some(
                            (change) => {
                                const isMac = process.platform === 'darwin';
                                const isCtrlOrCmd = isMac ? change.text.includes('\u0010') : change.text.includes('\n');
                                return isCtrlOrCmd;
                            }
                        );
    
                        if (isCtrlOrCmdPressed && !completionInserted) {
                            // Ensure that we insert the completion text only once
                            completionInserted = true;
    
                            // Remove the preview decoration before applying the final completion
                            textEditor.setDecorations(previewDecorationType, []);
    
                            const edit = new vscode.WorkspaceEdit();
                            const insertPosition = new vscode.Position(position.line, 0);
    
                            // Avoid duplicating the completion text
                            if (!document.getText().includes(completionText)) {
                                edit.insert(document.uri, insertPosition, '\n' + completionText);
                                await vscode.workspace.applyEdit(edit);
                            }
    
                            const newPosition = new vscode.Position(position.line + lines.length, lines[lines.length - 1].length);
                            textEditor.selection = new vscode.Selection(newPosition, newPosition);
    
                            disposable.dispose(); // Clean up the listener after accepting the completion
                        }
                    }
                });
    
            } catch (err: any) {
                vscode.window.showErrorMessage(
                    "Fabelous Autocoder encountered an error: " + err.message
                );
                console.log(err);
            }
        }
    );
    
    
}



async function provideCompletionItems(document: vscode.TextDocument, position: vscode.Position, cancellationToken: vscode.CancellationToken) {
    const item = new vscode.CompletionItem("Fabelous autocompletion");
    item.insertText = new vscode.SnippetString('${1:}');
    
    if (responsePreview) {
        await new Promise(resolve => setTimeout(resolve, responsePreviewDelay * 1000));
        if (cancellationToken.isCancellationRequested) {
            return [ item ];
        }

        const context = getContextLines(document, position);
        const fimPrompt = createFIMPrompt(context, document.languageId);

        try {
            const response_preview = await axios.post(apiEndpoint, {
                model: apiModel,
                prompt: fimPrompt,
                stream: false,
                raw: true,
                options: {
                    num_predict: responsePreviewMaxTokens,
                    temperature: apiTemperature,
                    stop: ['<fim_suffix>', '\n', '```'],
                    ...(keepAlive && { keep_alive: keepAlive }),
                    ...(topP && { top_p: topP }),
                }
            }, {
                cancelToken: new axios.CancelToken((c) => {
                    cancellationToken.onCancellationRequested(() => c("Autocompletion request terminated by completion cancel"));
                })
            });
        } catch (error) {
            console.error("Error fetching preview:", error);
        }
    }

    item.documentation = new vscode.MarkdownString('Press `Enter` to get an autocompletion from Fabelous Autocoder');
    if (continueInline || !responsePreview) {
        item.command = {
            command: 'fabelous-autocoder.autocomplete',
            title: 'Fabelous Autocomplete',
            arguments: [cancellationToken]
        };
    }
    return [item];
}

function activate(context: vscode.ExtensionContext) {
    const completionProvider = vscode.languages.registerCompletionItemProvider("*", {
        provideCompletionItems
    },
        ...completionKeys.split("")
    );
    const externalAutocompleteCommand = vscode.commands.registerTextEditorCommand(
        "fabelous-autocoder.autocomplete",
        (textEditor, _, cancellationToken?) => {
            autocompleteCommand(textEditor, cancellationToken);
        }
    );
    context.subscriptions.push(completionProvider);
    context.subscriptions.push(externalAutocompleteCommand);
}

function deactivate() { }

module.exports = {
    activate,
    deactivate,
};