bastools/api/src/main/java/io/github/applecommander/bastools/api/model/ApplesoftKeyword.java

package io.github.applecommander.bastools.api.model;

import java.io.IOException;
import java.io.Reader;
import java.io.StreamTokenizer;
import java.io.StringReader;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Objects;
import java.util.Optional;

/** All elements of AppleSoft that are tokenized in some manner.  "Keyword" was picked as it is not the word token. ;-) */
public enum ApplesoftKeyword {
    END(0x80, "END"), 
    FOR(0x81, "FOR"), 
    NEXT(0x82, "NEXT"), 
    DATA(0x83, "DATA"), 
    INPUT(0x84, "INPUT"), 
    DEL(0x85, "DEL"), 
    DIM(0x86, "DIM"), 
    READ(0x87, "READ"), 
    GR(0x88, "GR"), 
    TEXT(0x89, "TEXT"), 
    PR(0x8A, "PR#"), 
    IN(0x8B, "IN#"), 
    CALL(0x8C, "CALL"), 
    PLOT(0x8D, "PLOT"), 
    HLIN(0x8E, "HLIN"), 
    VLIN(0x8F, "VLIN"), 
    HGR2(0x90, "HGR2"), 
    HGR(0x91, "HGR"), 
    HCOLOR(0x92, "HCOLOR="), 
    HPLOT(0x93, "HPLOT"), 
    DRAW(0x94, "DRAW"), 
    XDRAW(0x95, "XDRAW"), 
    HTAB(0x96, "HTAB"), 
    HOME(0x97, "HOME"), 
    ROT(0x98, "ROT="), 
    SCALE(0x99, "SCALE="), 
    SHLOAD(0x9A, "SHLOAD"), 
    TRACE(0x9B, "TRACE"), 
    NOTRACE(0x9C, "NOTRACE"), 
    NORMAL(0x9D, "NORMAL"), 
    INVERSE(0x9E, "INVERSE"), 
    FLASH(0x9F, "FLASH"), 
    COLOR(0xA0, "COLOR="), 
    POP(0xA1, "POP"), 
    VTAB(0xA2, "VTAB"), 
    HIMEM(0xA3, "HIMEM:"), 
    LOMEM(0xA4, "LOMEM:"), 
    ONERR(0xA5, "ONERR"), 
    RESUME(0xA6, "RESUME"), 
    RECALL(0xA7, "RECALL"), 
    STORE(0xA8, "STORE"), 
    SPEED(0xA9, "SPEED="), 
    LET(0xAA, "LET"), 
    GOTO(0xAB, "GOTO"), 
    RUN(0xAC, "RUN"), 
    IF(0xAD, "IF"), 
    RESTORE(0xAE, "RESTORE"), 
    amp(0xAF, "&"), 
    GOSUB(0xB0, "GOSUB"), 
    RETURN(0xB1, "RETURN"), 
    REM(0xB2, "REM"), 
    STOP(0xB3, "STOP"), 
    ON(0xB4, "ON"), 
    WAIT(0xB5, "WAIT"), 
    LOAD(0xB6, "LOAD"), 
    SAVE(0xB7, "SAVE"), 
    DEF(0xB8, "DEF"), 
    POKE(0xB9, "POKE"), 
    PRINT(0xBA, "PRINT"), 
    questionmark(0xBA, "?"), // Alternate form of PRINT
    CONT(0xBB, "CONT"), 
    LIST(0xBC, "LIST"), 
    CLEAR(0xBD, "CLEAR"), 
    GET(0xBE, "GET"), 
    NEW(0xBF, "NEW"), 
    TAB(0xC0, "TAB("), 
    TO(0xC1, "TO"), 
    FN(0xC2, "FN"), 
    SPC(0xC3, "SPC("), 
    THEN(0xC4, "THEN"), 
    AT(0xC5, "AT"), 
    NOT(0xC6, "NOT"), 
    STEP(0xC7, "STEP"), 
    add(0xC8, "+"), 
    sub(0xC9, "-"), 
    mul(0xCA, "*"), 
    div(0xCB, "/"), 
    pow(0xCC, "^"), 
    AND(0xCD, "AND"), 
    OR(0xCE, "OR"), 
    gt(0xCF, ">"), 
    eq(0xD0, "="), 
    lt(0xD1, "<"), 
    SGN(0xD2, "SGN"), 
    INT(0xD3, "INT"), 
    ABS(0xD4, "ABS"), 
    USR(0xD5, "USR"), 
    FRE(0xD6, "FRE"), 
    SCRN(0xD7, "SCRN("), 
    PDL(0xD8, "PDL"), 
    POS(0xD9, "POS"), 
    SQR(0xDA, "SQR"), 
    RND(0xDB, "RND"), 
    LOG(0xDC, "LOG"), 
    EXP(0xDD, "EXP"), 
    COS(0xDE, "COS"), 
    SIN(0xDF, "SIN"), 
    TAN(0xE0, "TAN"), 
    ATN(0xE1, "ATN"), 
    PEEK(0xE2, "PEEK"), 
    LEN(0xE3, "LEN"), 
    STR(0xE4, "STR$"), 
    VAL(0xE5, "VAL"), 
    ASC(0xE6, "ASC"), 
    CHR(0xE7, "CHR$"), 
    LEFT(0xE8, "LEFT$"), 
    RIGHT(0xE9, "RIGHT$"), 
    MID(0xEA, "MID$");
	
	/**
	 * The AppleSoft token value.  Token is overloaded, so "code" is good enough.
	 */
	public final int code;
	/**
	 * Full text of the token.
	 */
	public final String text;
	/**
	 * Token parts as seen by the StreamTokenizer.
	 */
	public final List<String> parts;
	/** 
	 * Indicates that this needs _just_ a closing right parenthesis since the 
	 * opening left parenthesis is included in the token 
	 */
	public boolean needsRParen;
	
	private ApplesoftKeyword(int code, String text) {
		this.code = code;
		this.text = text;
		
		try {
			// A bit brute-force, but should always match the tokenizer configuration!
			List<String> list = new ArrayList<>();
			StreamTokenizer t = tokenizer(new StringReader(text));
			while (t.nextToken() != StreamTokenizer.TT_EOF) {
				switch (t.ttype) {
				case StreamTokenizer.TT_WORD:
					list.add(t.sval);
					break;
				default:
					list.add(String.format("%c", t.ttype));
					break;
				}
			}
			this.parts = Collections.unmodifiableList(list);
			this.needsRParen = parts.contains("(");
		} catch (IOException ex) {
			throw new RuntimeException(ex);
		}
	}
	
	public boolean equalsIgnoreCase(String value) {
		return this.text.equalsIgnoreCase(value);
	}
	
	@Override
	public String toString() {
		return String.format("%s (%02x)", text, code);
	}
	
	/** Utility method to create a shared definition for AppleSoft file parsing. */
	public static StreamTokenizer tokenizer(Reader r) {
		StreamTokenizer tokenizer = new StreamTokenizer(r);
		tokenizer.resetSyntax();
		tokenizer.wordChars('a', 'z');
		tokenizer.wordChars('A', 'Z');
		tokenizer.wordChars('?', '?');  // For '?' form of PRINT
		tokenizer.wordChars('$', '$');	// Experiment to pull in string marker
		tokenizer.wordChars('%', '%');	// Experiment to pull in integer marker
		tokenizer.wordChars(128 + 32, 255);
		tokenizer.whitespaceChars(0, ' ');
		tokenizer.quoteChar('"');
		tokenizer.parseNumbers();
		// This resets part of parseNumbers to match AppleSoft tokenization!
		tokenizer.ordinaryChar('-');
		tokenizer.eolIsSignificant(true);
		// Special case: Allow a single line comment with ' as that is not part of language
		tokenizer.commentChar('\'');
		return tokenizer;
	}
	
	/** Utility method to locate a keyword ignoring case. */
	public static Optional<ApplesoftKeyword> find(String value) {
		Objects.requireNonNull(value);
		for (ApplesoftKeyword kw : values()) {
			if (value.equalsIgnoreCase(kw.parts.get(0))) {
				return Optional.of(kw);
			}
		}
		return Optional.empty();
	}
}