package net.knarcraft.ffmpegconverter;

import java.util.ArrayList;
import java.util.List;

public class Parser {

    /**
     * This function parses command inputs into understandable converter instructions
     * @param tokens <p>A list of tokens containing all arguments</p>
     */
    private static void parse(List<String> tokens) {
        String[] types = {"animeconverter", "audioconverter", "videoconverter"};
        Main.converterArgument[] commonArgs = {
                new Main.converterArgument("-recursions", true, Main.converterArgumentValueType.INT)
        };
        Main.converterArgument[] animeArgs = {

        };
        Main.converterArgument[] audioArgs = {
                new Main.converterArgument("-outext", true,
                        Main.converterArgumentValueType.SINGLE_VALUE)
        };
        Main.converterArgument[] videoArgs = {
                new Main.converterArgument("-outext", true,
                        Main.converterArgumentValueType.SINGLE_VALUE)
        };
        String type = tokens.get(0).toLowerCase();
        if (!Main.listContains(types, s -> s.equals(type))) {
            throw new IllegalArgumentException("Unknown converter type chosen.");
        }
        if (tokens.size() < 2) {
            throw new IllegalArgumentException("No file/folder path in argument.");
        }
        for (int i = 1; i < tokens.size() - 1; i++) {
            //TODO: Find the type of argument and check the value
            //TODO: Find an executable way to represent the chain of commands parsed
        }
    }

    /**
     * Tokenizes a string
     * @param input <p>A string.</p>
     * @return <p>A list of tokens.</p>
     */
    public static List<String> tokenize(String input) {
        List<String> tokens = new ArrayList<>();
        boolean startedQuote = false;
        StringBuilder currentToken = new StringBuilder();
        for (int i = 0; i < input.length(); i++) {
            char character = input.charAt(i);
            switch (character) {
                case ' ':
                    if (!startedQuote) {
                        //If not inside "", a space marks the end of a parameter
                        if (isNotEmpty(currentToken)) {
                            tokens.add(currentToken.toString());
                        }
                        currentToken = new StringBuilder();
                    } else {
                        currentToken.append(character);
                    }
                    break;
                case '"':
                    if (startedQuote) {
                        //This quote signifies the end of the argument
                        if (isNotEmpty(currentToken)) {
                            tokens.add(currentToken.toString());
                            currentToken = new StringBuilder();
                        }
                        startedQuote = false;
                    } else {
                        //This quote signifies the start of the argument
                        startedQuote = true;
                        currentToken = new StringBuilder();
                    }
                    break;
                default:
                    //Adds a normal character to the token. Adds the current token to tokens if at the end of the input.
                    currentToken.append(character);
                    if (i == input.length() - 1) {
                        tokens.add(currentToken.toString());
                    }
                    break;
            }
        }
        return tokens;
    }

    /**
     * Checks whether a string builder is empty
     * @param builder <p>The string builder to check.</p>
     * @return <p>True if the string builder is non empty.</p>
     */
    private static boolean isNotEmpty(StringBuilder builder) {
        return !builder.toString().trim().equals("");
    }
}