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`;
}


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;
                // Remove any FIM tags and leading/trailing whitespace
                completionText = completionText.replace(/<fim_middle>|<fim_suffix>|<fim_prefix>/g, '').trim();

                // Remove the context lines
                const startLine = Math.max(0, position.line - 1);
                const endLine = position.line;
                const rangeToReplace = new vscode.Range(
                    new vscode.Position(startLine, 0),
                    new vscode.Position(endLine, document.lineAt(endLine).text.length)
                );

                // Apply the edit
                const edit = new vscode.WorkspaceEdit();
                edit.replace(document.uri, rangeToReplace, completionText);
                await vscode.workspace.applyEdit(edit);

                // Move the cursor to the end of the inserted text
                const newPosition = new vscode.Position(startLine + completionText.split('\n').length - 1, completionText.split('\n').pop()!.length);
                textEditor.selection = new vscode.Selection(newPosition, newPosition);

                progress.report({ message: "Fabelous completion finished." });

            } 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,
};