main.bal

import wso2/nballerina.bir;
import wso2/nballerina.nback;
import wso2/nballerina.comm.err;
import wso2/nballerina.comm.diagnostic as d;

import ballerina/io;
import ballerina/file;

type CompileError err:Diagnostic|io:Error|file:Error;

public type Options record {
    boolean testJsonTypes = false;
    boolean showTypes = false;
    int? debugLevel;
    // outDir also implies treating each file as a separate module
    string? outDir = ();
    string? expectOutDir = ();
    string? gc = ();
    string? htmlError = ();
    boolean bir = false;
    *OutputOptions;
};

const DEFAULT_ROOT_MODULE_NAME = "root";
final bir:ModuleId DEFAULT_ROOT_MODULE_ID = { org: "", names: [DEFAULT_ROOT_MODULE_NAME] };

const SOURCE_EXTENSION = ".bal";
const TEST_EXTENSION = ".balt";
public function main(string[] filenames, *Options opts) returns error? {
    if filenames.length() == 0 {
        return error("no input files");
    }
    if opts.testJsonTypes {
        if filenames.length() > 1 {
            return error("multiple input files not supported with --testJsonTypes");
        }
        check testJsonTypes(filenames[0]);
        return;
    }
    if opts.showTypes {
        if filenames.length() > 1 {
            return error("multiple input files not supported with --showTypes");
        }
        check printDiagnostic(showTypes([{ filename: filenames[0] }]));
        return;
    }
    nback:Options nbackOptions = {
        gcName: check nback:validGcName(opts.gc),
        debugLevel: check nback:validDebugLevel(opts.debugLevel)
    };
    int errorFileCount = 0;
    d:Printer dPrinter;
    string? errorFilename = opts.htmlError;
    if errorFilename != () {
        dPrinter = new d:HtmlPrinter(errorFilename);
    }
    else {
        dPrinter = new d:ConsolePrinter(io:stderr);
    }
    foreach string filename in filenames {
        var [basename, ext] = basenameExtension(filename);
        if ext == SOURCE_EXTENSION {
            string outputBasename = check chooseOutputBasename(basename, opts.outDir);
            Emitter emitter;
            if opts.bir {
                emitter = new BirEmitter(outputBasename);
            }
            else {
                emitter = new LlvmEmitter(outputBasename, nbackOptions, opts);
            }
            CompileError? err = compileBalFile({ filename }, basename, emitter);
            if err is err:Internal {
                panic error(d:toString(err.detail()), err);
            }
            else if err is err:Diagnostic {
                errorFileCount += 1;
                dPrinter.print(err.detail());
            }
            else {
                _ = check err;
            }
        }
        else if ext == TEST_EXTENSION {
            check compileBaltFile(filename, basename, opts.outDir ?: check file:parentPath(filename), nbackOptions, opts);
        }
        else if ext == () {
            return error("input filename must have a .bal or .balt extension");
        }
        else {
            return error(d:messageFormat(`unsupported extension ${ext}`));
        }
    }
    check dPrinter.close();
    if errorFileCount != 0 {
        string files = errorFileCount == 1 ? "file" : "files";
        return error(string `compilation of ${errorFileCount} ${files} failed`);
    }
}

function printDiagnostic(CompileError? err) returns CompileError? {
    if err is err:Diagnostic {
        foreach string line in d:format(err.detail()) {
            io:fprintln(io:stderr, line);
        }
    }
    return err;
}

// Basename here means filename without extension
function chooseOutputBasename(string sourceBasename, string? outDir = ()) returns string|error {
    if outDir == () {
        return sourceBasename;
    }
    else {
        return check file:joinPath(outDir, check file:basename(sourceBasename));
    }
}

// Note that this converts extension to lower case
function basenameExtension(string filename) returns [string, string?] {
    int? extIndex = filename.lastIndexOf(".");
    if extIndex is int {
        return [filename.substring(0, extIndex), filename.substring(extIndex).toLowerAscii()];
    }
    return [filename, ()];
}