package slangc.api;

import slang.data.Mappable;
import slang.streams.SyncOutput;
import slang.streams.SyncInput;

import slangc.parser.Annotation;
import slangc.parser.AnnotationType;
import slangc.parser.Branch;
import slangc.parser.LocationAnnotation;
import slangc.parser.ErrorAnnotation;
import slangc.parser.NoteAnnotation;
import slangc.parser.LocationType;
import slangc.parser.Node;
import slangc.parser.Parse;
import slangc.parser.Scan;
import slangc.parser.Source;
import slangc.parser.Token;
import slangc.parser.WarningType;

/**
 * Holds all of the information for a unit (sourceFile file) and abstracts away the semantics of scanning/parsing/checking them.
 * @author Zak
 *
 */
public class Unit {
	private CompilerWorld world;
	private Source source;
	private Scan scan = null;
	private Branch parse = null;
	
	public Unit(CompilerWorld world, Source source) {
		this.world = world;
		this.source = source;
	}

	public CompilerWorld getWorld() {
		return world;
	}
	
	public Source getSource() {
		return source;
	}
	
	public String getFilename() {
		return getSource().getFilename();
	}

	int hashCache = -1;
    public int getCacheHash() {
		if (hashCache < 0) {
        	hashCache = Mappable.nonNegativeHashOf(getSource().getString(0, getSource().getIndexLength()));
		}
		return hashCache;
    }

    public boolean updateCache() {
        try {
            Branch b = parse();
            // TODO: Check if needs updating here
            SyncOutput<byte> o = world.getCacheManager().getOutput(getCacheName());
            if (o == null) {
                return false;
            }
            b.dumpBinary(o);
            o.close();
            return true;
        } catch (duck d) {
            Log.line("WARNING: Updating cache failed with error");
            return false;
        }
    }

    public String getCacheName() {
        return "." + getCacheHash() + "." + getSource().getIndexLength() + ".cache";
    }
	
	public String getPackageName() {
		Branch pkg = (Branch) parse().getSubnode(0);
		if (pkg == null) {
			return "defpkg"; //throw new Error("Invalid package format");
		}
		pkg = (Branch) pkg.getSubnode(1);
		if (pkg == null) {
			throw new Error("Invalid package format");
		}
		String name = "";
		for (int i = 0; i < pkg.countSubnodes(); i++) {
			Branch sub = (Branch) pkg.getSubnode(i);
			if (sub == null) {
				throw new Error("Invalid package format");
			}
			Token token = (Token) sub.getSubnode(0);
			if (token == null) {
				throw new Error("Invalid package format");
			}
			name += token.getSnippet().getSource();
		}
		return name;
	}
	
	public Scan scan() {
		if (scan == null) {
			scan = new Scan(world.getLanguage(), source);
			//scan.scanPedantic();
            scan.scanQuick();
		}
		
		return scan;
	}

    public Branch loadCache(SyncInput<byte> inp) {
        scan = new Scan(world.getLanguage(), source);
        parse = (Branch) Node.loadBinary(scan, inp);
        inp.close();
        _wasCached = true;
        return parse;
    }
    
    private boolean _wasCached = false;

    public boolean wasCached() {
        return _wasCached;
    }
	
	public Branch parse() {
		if (parse == null) {
            SyncInput<byte> cacheIn = world.getCacheManager().getInput(getCacheName());
            if (cacheIn != null) {
				//Log.line("Loading from cache...");
                return loadCache(cacheIn);
            }
			//Log.line("Not cached...");
			Scan s = scan();
			Parse p = new Parse();
			parse = (Branch) p.parseUnit(s);
		}
		
		return parse;
	}
	
	private Token checkRecursively(Branch b, Token p) {
        if (!Node.mightHaveErrors && !Node.mightHaveWarnings) {
            return p;
        }
		if (p != null && b.countAnnotations(AnnotationType.LOCATION) == 0) {
			b.annotate(new LocationAnnotation(LocationType.AFTER, p));
		}
		for (int i = 0; i < b.countSubnodes(); i++) {
			Node n = b.getSubnode(i);
			if (n instanceof Token) {
				p = (Token) n;
				p.annotate(new LocationAnnotation(LocationType.AROUND, p));
			} else if (n == null) {
				b.annotate(WarningType.INTERNAL_WARNING, "Had a null member");
			} else {
				p = checkRecursively((Branch) n, p);
			}
		}
		if (p != null && b.countAnnotations(AnnotationType.LOCATION) == 0) {
			b.annotate(new LocationAnnotation(LocationType.AROUND, p));
		}
		
		return p;
	}
	
	public int checkErrors(int verbosity) {
		int nerrors = 0;
		
		Branch p = parse();
		
		checkRecursively(p, null);
		
		//getWorld().getReporter().note("CHECKING", getFilename());
		
		//getWorld().getReporter().note("CHECKING", "File '" + getFilename() + "' reports package as '" + getPackageName() + "'");
		
		nerrors += p.countErrorsRecursively();
		
		if (nerrors != 0) {
			getWorld().getReporter().note("ERRORS", "Found " + nerrors + " errors  in '" + getFilename() + "', dumping AST:");
			dump(getWorld().getReporter(), parse(), verbosity);
		}
		
		return nerrors;
	}
	
	private static void dump(Reporter out, Node n, int verbosity) {
		dump(out, n, "", verbosity < 5 ? "" : "  ", verbosity);
	}
	
	private static void dump(Reporter out, Node n, String curindent, String subindent, int verbosity) {
		if (n instanceof Branch) {
			dumpBranch(out, (Branch) n, curindent, subindent, verbosity);
		} else if (n instanceof Token) {
			dumpToken(out, (Token) n, curindent, subindent, verbosity);
		} else if (n instanceof Annotation) {
			dumpAnnotation(out, (Annotation) n, curindent, subindent, verbosity);
		} else if (n == null) {
			out.note("DUMP", curindent + "-! UH-OH !- null");
		} else {
			out.note("DUMP", curindent + "-! TO-DO !- code to dump " + n.toString());
		}
	}
	
	private static void dumpAnnotations(Reporter out, Node n, String curindent, String subindent, int verbosity) {
		for (int i = 0; i < n.countAnnotations(); i++) {
			dump(out, n.getAnnotation(i), curindent + subindent, subindent, verbosity);
		}
	}

	private static void dumpBranch(Reporter out, Branch b, String curindent, String subindent, int verbosity) {
		if (verbosity < 10 && b.countErrorsRecursively() == 0) {
			if (verbosity > 2) out.note("DUMP", curindent + "-> " + b.getNodeType().name() + " (...)");
			return;
		}
		if (verbosity >= 5 || b.countErrorsHere() > 0) {
			if (verbosity > 2) out.note("DUMP", curindent + "-> " + b.getNodeType());
			dumpAnnotations(out, b, curindent, subindent, verbosity);
		}
		for (int i = 0; i < b.countSubnodes(); i++) {
			dump(out, b.getSubnode(i), curindent + subindent, subindent, verbosity);
		}
	}

	private static void dumpToken(Reporter out, Token t, String curindent, String subindent, int verbosity) {
		if (verbosity >= 5) {
			out.note("DUMP", curindent + "-. " + t);
			dumpAnnotations(out, t, curindent, subindent, verbosity);
		}
	}

	private static void dumpAnnotation(Reporter out, Annotation a, String curindent, String subindent, int verbosity) {
		if (a instanceof ErrorAnnotation) {
			out.note("DUMP", curindent + "-! " + ((ErrorAnnotation) a).getErrorType().name());
		} else if (a instanceof NoteAnnotation) {
			out.note("DUMP", curindent + "-+ " + ((NoteAnnotation) a).getText());
		} else if (a instanceof LocationAnnotation) {
			out.note("DUMP", curindent + "-- " + ((LocationAnnotation) a).niceString());
		} else {
			out.note("DUMP", curindent + "-+ " + a.toString());
		}
		dumpAnnotations(out, a, curindent, subindent, verbosity);
	}
}