// xscript-cli - XScript definition file validator and parser
//
// Usage:
//   xscript-cli check <file.xscript>         - Check syntax and validate references
//   xscript-cli check-dir <directory>        - Check all .xscript files in directory
//   xscript-cli list-types <file.xscript>    - List all types defined in file
//   xscript-cli info <file.xscript> <type>   - Show info about a specific type

#include <QCoreApplication>
#include <QCommandLineParser>
#include <QFile>
#include <QFileInfo>
#include <QDir>
#include <QDirIterator>
#include <QTextStream>

#include "lexer.h"
#include "parser.h"
#include "typeregistry.h"

static QTextStream out(stdout);
static QTextStream err(stderr);

// Color codes for terminal output
namespace Color {
    const char* Reset = "\033[0m";
    const char* Red = "\033[31m";
    const char* Green = "\033[32m";
    const char* Yellow = "\033[33m";
    const char* Blue = "\033[34m";
    const char* Cyan = "\033[36m";
    const char* Bold = "\033[1m";
}

struct CheckResult {
    QString filePath;
    QString fileName;
    bool success = false;
    QString errorMessage;
    QStringList typeNames;
    int warningCount = 0;
    QStringList warnings;
};

CheckResult checkFile(const QString& filePath) {
    CheckResult result;
    result.filePath = filePath;
    result.fileName = QFileInfo(filePath).fileName();

    QFile file(filePath);
    if (!file.open(QIODevice::ReadOnly | QIODevice::Text)) {
        result.errorMessage = "Failed to open file";
        return result;
    }

    QString content = QString::fromUtf8(file.readAll());
    file.close();

    try {
        Lexer lexer(content);
        Parser parser(std::move(lexer));
        Module module = parser.parseModule();

        result.success = true;

        // Collect type names
        for (auto it = module.types.begin(); it != module.types.end(); ++it) {
            result.typeNames.append(it.key());
        }

        // Check for potential issues (warnings)
        for (auto it = module.types.begin(); it != module.types.end(); ++it) {
            const TypeDef& td = it.value();

            // Warn if root type has no criteria
            if (td.isRoot && td.criteria.isEmpty()) {
                result.warnings.append(QString("Type '%1' is root but has no criteria block").arg(td.name));
                result.warningCount++;
            }

            // Warn if type has no body
            if (td.body.isEmpty()) {
                result.warnings.append(QString("Type '%1' has an empty body").arg(td.name));
                result.warningCount++;
            }
        }

    } catch (const std::exception& e) {
        result.errorMessage = QString::fromStdString(e.what());
    }

    return result;
}

int cmdCheck(const QString& filePath) {
    CheckResult result = checkFile(filePath);

    if (result.success) {
        out << Color::Green << "OK" << Color::Reset << " " << result.fileName;
        if (!result.typeNames.isEmpty()) {
            out << " (" << result.typeNames.size() << " type(s))";
        }
        out << "\n";

        for (const QString& warning : result.warnings) {
            out << Color::Yellow << "  WARNING: " << Color::Reset << warning << "\n";
        }

        return 0;
    } else {
        err << Color::Red << "ERROR" << Color::Reset << " " << result.fileName << "\n";
        err << "  " << result.errorMessage << "\n";
        return 1;
    }
}

int cmdCheckDir(const QString& dirPath) {
    QDir dir(dirPath);
    if (!dir.exists()) {
        err << Color::Red << "Error: Directory does not exist: " << dirPath << Color::Reset << "\n";
        return 1;
    }

    QDirIterator it(dirPath, {"*.xscript"}, QDir::Files, QDirIterator::Subdirectories);

    int totalFiles = 0;
    int successCount = 0;
    int errorCount = 0;
    int warningCount = 0;
    QStringList allTypes;
    QStringList failedFiles;

    while (it.hasNext()) {
        QString filePath = it.next();
        totalFiles++;

        CheckResult result = checkFile(filePath);

        // Show relative path from the directory
        QString relativePath = dir.relativeFilePath(filePath);

        if (result.success) {
            successCount++;
            out << Color::Green << "OK" << Color::Reset << " " << relativePath;
            if (!result.typeNames.isEmpty()) {
                out << " (" << result.typeNames.size() << " type(s))";
                allTypes.append(result.typeNames);
            }
            out << "\n";

            warningCount += result.warningCount;
            for (const QString& warning : result.warnings) {
                out << Color::Yellow << "  WARNING: " << Color::Reset << warning << "\n";
            }
        } else {
            errorCount++;
            failedFiles.append(relativePath);
            err << Color::Red << "ERROR" << Color::Reset << " " << relativePath << "\n";
            err << "  " << result.errorMessage << "\n";
        }
    }

    // Summary
    out << "\n" << Color::Bold << "Summary:" << Color::Reset << "\n";
    out << "  Files checked: " << totalFiles << "\n";
    out << "  " << Color::Green << "Passed: " << successCount << Color::Reset << "\n";
    if (errorCount > 0) {
        out << "  " << Color::Red << "Failed: " << errorCount << Color::Reset << "\n";
    }
    if (warningCount > 0) {
        out << "  " << Color::Yellow << "Warnings: " << warningCount << Color::Reset << "\n";
    }
    out << "  Total types: " << allTypes.size() << "\n";

    // Validate cross-file references
    if (!allTypes.isEmpty()) {
        TypeRegistry registry;
        int refErrors = 0;

        // Re-load all files into a single registry
        QDirIterator it2(dirPath, {"*.xscript"}, QDir::Files, QDirIterator::Subdirectories);
        while (it2.hasNext()) {
            QString filePath = it2.next();
            QFile file(filePath);
            if (file.open(QIODevice::ReadOnly | QIODevice::Text)) {
                try {
                    registry.ingestScript(QString::fromUtf8(file.readAll()), filePath);
                } catch (...) {
                    // Already reported
                }
            }
        }

        QStringList refErrorList = registry.validateTypeReferences();
        if (!refErrorList.isEmpty()) {
            out << "\n" << Color::Red << "Reference errors:" << Color::Reset << "\n";
            for (const QString& refErr : refErrorList) {
                out << "  " << refErr << "\n";
                refErrors++;
            }
        }

        if (refErrors > 0) {
            errorCount += refErrors;
        }
    }

    return (errorCount > 0) ? 1 : 0;
}

int cmdListTypes(const QString& filePath) {
    CheckResult result = checkFile(filePath);

    if (!result.success) {
        err << Color::Red << "Error parsing file:" << Color::Reset << "\n";
        err << "  " << result.errorMessage << "\n";
        return 1;
    }

    out << Color::Bold << "Types in " << result.fileName << ":" << Color::Reset << "\n";

    // Re-parse to get more details
    QFile file(filePath);
    if (!file.open(QIODevice::ReadOnly | QIODevice::Text)) {
        return 1;
    }

    QString content = QString::fromUtf8(file.readAll());
    Lexer lexer(content);
    Parser parser(std::move(lexer));
    Module module = parser.parseModule();

    for (auto it = module.types.begin(); it != module.types.end(); ++it) {
        const TypeDef& td = it.value();

        out << "  " << Color::Cyan << td.name << Color::Reset;

        QStringList flags;
        if (td.isRoot) flags.append("root");
        if (!td.display.isEmpty()) flags.append(QString("display=\"%1\"").arg(td.display));
        if (td.order == ByteOrder::BE) flags.append("BE");
        else flags.append("LE");

        if (!flags.isEmpty()) {
            out << " [" << flags.join(", ") << "]";
        }
        out << "\n";

        if (!td.criteria.isEmpty()) {
            out << "    criteria: " << td.criteria.size() << " statement(s)\n";
        }
        out << "    body: " << td.body.size() << " statement(s)\n";
    }

    return 0;
}

int cmdInfo(const QString& filePath, const QString& typeName) {
    QFile file(filePath);
    if (!file.open(QIODevice::ReadOnly | QIODevice::Text)) {
        err << Color::Red << "Error: Failed to open file" << Color::Reset << "\n";
        return 1;
    }

    QString content = QString::fromUtf8(file.readAll());

    try {
        Lexer lexer(content);
        Parser parser(std::move(lexer));
        Module module = parser.parseModule();

        if (!module.types.contains(typeName)) {
            err << Color::Red << "Error: Type '" << typeName << "' not found" << Color::Reset << "\n";
            err << "Available types:\n";
            for (const QString& name : module.types.keys()) {
                err << "  " << name << "\n";
            }
            return 1;
        }

        const TypeDef& td = module.types[typeName];

        out << Color::Bold << "Type: " << td.name << Color::Reset << "\n";
        out << "  Root: " << (td.isRoot ? "yes" : "no") << "\n";
        out << "  Display: " << (td.display.isEmpty() ? "(none)" : td.display) << "\n";
        out << "  Byte order: " << (td.order == ByteOrder::BE ? "big-endian" : "little-endian") << "\n";
        out << "  Criteria statements: " << td.criteria.size() << "\n";
        out << "  Body statements: " << td.body.size() << "\n";

    } catch (const std::exception& e) {
        err << Color::Red << "Error parsing file: " << e.what() << Color::Reset << "\n";
        return 1;
    }

    return 0;
}

int main(int argc, char *argv[]) {
    QCoreApplication app(argc, argv);
    QCoreApplication::setApplicationName("xscript-cli");
    QCoreApplication::setApplicationVersion("1.0.0");

    QCommandLineParser parser;
    parser.setApplicationDescription("XScript definition file validator and parser");
    parser.addHelpOption();
    parser.addVersionOption();

    parser.addPositionalArgument("command", "Command to run: check, check-dir, list-types, info");
    parser.addPositionalArgument("args", "Command arguments", "[args...]");

    parser.process(app);

    const QStringList args = parser.positionalArguments();

    if (args.isEmpty()) {
        err << "Error: No command specified\n\n";
        err << "Usage:\n";
        err << "  xscript-cli check <file.xscript>         - Check syntax and validate\n";
        err << "  xscript-cli check-dir <directory>        - Check all .xscript files\n";
        err << "  xscript-cli list-types <file.xscript>    - List all types in file\n";
        err << "  xscript-cli info <file.xscript> <type>   - Show type info\n";
        return 1;
    }

    const QString command = args[0];

    if (command == "check") {
        if (args.size() < 2) {
            err << "Error: check requires a file path\n";
            return 1;
        }
        return cmdCheck(args[1]);
    }
    else if (command == "check-dir") {
        if (args.size() < 2) {
            err << "Error: check-dir requires a directory path\n";
            return 1;
        }
        return cmdCheckDir(args[1]);
    }
    else if (command == "list-types") {
        if (args.size() < 2) {
            err << "Error: list-types requires a file path\n";
            return 1;
        }
        return cmdListTypes(args[1]);
    }
    else if (command == "info") {
        if (args.size() < 3) {
            err << "Error: info requires a file path and type name\n";
            return 1;
        }
        return cmdInfo(args[1], args[2]);
    }
    else {
        err << "Error: Unknown command '" << command << "'\n";
        err << "Valid commands: check, check-dir, list-types, info\n";
        return 1;
    }
}