import * as vscode from 'vscode';
import * as child_process from 'child_process';
import documentclass_symbols from '../dictionary/documentclass_symbols';

/**
	${workspaceFolder} - the path of the workspace folder that contains the tasks.json file
	${workspaceFolderBasename} - the name of the workspace folder that contains the tasks.json file without any slashes (/)
	${file} - the current opened file
	${relativeFile} - the current opened file relative to the workspace folder containing the file
	${fileBasename} - the current opened file's basename
	${fileBasenameNoExtension} - the current opened file's basename without the extension
	${fileDirname} - the current opened file's dirname
	${fileExtname} - the current opened file's extension
	${cwd} - the task runner's current working directory on startup
	${lineNumber} - the current selected line number in the active file
*/
function commandVariableSubstitution(variable: string, fileName: string): string {
	switch (variable) {
		case "${workspaceFolder}":
			return vscode.workspace.rootPath;
		case "${workspaceFolderBasename}":
			return vscode.workspace.rootPath; // TODO:
		case "${file}":
			return fileName;
		case "${relativeFile}":
			throw new Error("[ commandVariableSubstitution ] Not Implemented.");
		case "${fileBasename}":
			return fileName.substring(fileName.lastIndexOf('/') + 1);
		case "${fileBasenameNoExtension}":
			return fileName.substring(fileName.lastIndexOf('/') + 1, fileName.lastIndexOf('.'));
		case "${fileDirname}":
			return fileName.substring(0, fileName.lastIndexOf('/'));
		case "${fileExtname}":
			return fileName.substring(fileName.lastIndexOf('.') + 1);
		case "${cwd}":
			return vscode.workspace.rootPath;
		case "${lineNumber}":
			throw new Error("[ commandVariableSubstitution ] Not supported.");
		default:
			throw new Error("[ commandVariableSubstitution ] variable not found.");
	}
}

var decorationOptions: vscode.DecorationRenderOptions = {
	borderRadius: "3px",
	borderWidth: "1px",
	borderStyle: "solid",
	backgroundColor: "rgba(255,0,0,0.3)",
	borderColor: "rgba(255,100,100,0.15)"
};
var LaTeX_error_decoration_type: vscode.TextEditorDecorationType = vscode.window.createTextEditorDecorationType(decorationOptions);

export default {
	latex_pdflatex: function latex_pdflatex(textEditor: vscode.TextEditor, textEditorEdit: vscode.TextEditorEdit): void {
		function getHighliteLineNumbers(output: string): number[] {
			var lineNumbers: number[] = [];
			var outputLines: string[] = output.split("\n");

			for (let line = outputLines[0], i = 0; i < outputLines.length; line = outputLines[i++]) {
				if (line.startsWith("l.")) {
					var ln = Number.parseInt(line.substring(2, (line.indexOf(" ") + 1 || Infinity) - 1 ));
					if (lineNumbers.lastIndexOf(ln) < 0) {
						lineNumbers.push(ln);
					}
				}
			}
			return lineNumbers;
		}

		var document: vscode.TextDocument = textEditor.document;
		var fileName: string = this.settings.rootFile || document.fileName;
		var fileDir: string = fileName.substring(0, fileName.lastIndexOf('/'));
		var outputChannel: vscode.OutputChannel = this.outputChannel;

		outputChannel.clear(); // clear the outputChannel to only show the last output
		document.save(); // save the document before compile
		child_process.exec(
			// "pdflatex -synctex=1 -interaction=nonstopmode -output-directory=\"" + fileDir + "\" \"" + fileName + "\"",
			this.settings.pdflatex.replace(/\$\{[A-Za-z]+\}/g,(str) => commandVariableSubstitution(str, fileName)),
			{ cwd: fileDir }, // set the working directory
			(error: Error, stdout: string, stderr: string) => {
				var decorationRanges: vscode.Range[] = [];
				if (error) {
					var output: string = stdout + "\n" + stderr;
					var lineNumbers = getHighliteLineNumbers(output);

					for (var i = 0; i < lineNumbers.length; i++) {
						decorationRanges.push(new vscode.Range(
							new vscode.Position(lineNumbers[i] - 1, 0),
							new vscode.Position(lineNumbers[i] - 1, 1000)
						));
					}
					
					vscode.window.showErrorMessage("pdflatex Failed: see output.");
					outputChannel.show();
					outputChannel.appendLine("pdflatex Failed: " + error.message);
					outputChannel.append(output);
				} else {
					vscode.window.setStatusBarMessage("pdflatex succeeded: see output", 5000);
					outputChannel.appendLine("pdflatex succeeded: created file " + fileName.replace('.tex', '.pdf'));
				}
				textEditor.setDecorations(LaTeX_error_decoration_type, decorationRanges);
			}
		);
	},
	latex_makeindex: function latex_makeindex(textEditor: vscode.TextEditor, textEditorEdit: vscode.TextEditorEdit): void {
		var document: vscode.TextDocument = textEditor.document;
		var fileDir: string = document.fileName.substring(0, document.fileName.lastIndexOf('/'));
		var outputChannel: vscode.OutputChannel = this.outputChannel;
		
		textEditor.document.save(); // save the document before makeindex
		child_process.exec(
			// "makeindex " + document.fileName.substring(document.fileName.lastIndexOf('/') + 1, document.fileName.lastIndexOf('.')),
			this.settings.makeindex.replace(/\$\{[A-Za-z]+\}/g, (str) => commandVariableSubstitution(str, document.fileName)),
			{ cwd: fileDir }, // set the working directory
			(error: Error, stdout: string, stderr: string) => {
				if (error) {
					vscode.window.showErrorMessage("makeindex Failed: see output.");
					outputChannel.show();
					outputChannel.appendLine("makeindex Failed: " + error.message);
					outputChannel.append(stdout + "\n" + stderr);
				} else {
					vscode.window.setStatusBarMessage("makeindex succeeded", 5000);
					outputChannel.appendLine("makeindex succeeded: created *.ind file\n" + stdout);
				}
			}
		);
	}
}