package com.bugsnag.android;

import android.os.StrictMode;
import androidx.annotation.NonNull;

import java.lang.Thread;
import java.lang.Thread.UncaughtExceptionHandler;

/**
 * Provides automatic notification hooks for unhandled exceptions.
 */
class ExceptionHandler implements UncaughtExceptionHandler {

    private static final String STRICT_MODE_TAB = "StrictMode";
    private static final String STRICT_MODE_KEY = "Violation";

    private final UncaughtExceptionHandler originalHandler;
    private final StrictModeHandler strictModeHandler = new StrictModeHandler();
    private final Client client;
    private final Logger logger;

    ExceptionHandler(Client client, Logger logger) {
        this.client = client;
        this.logger = logger;
        this.originalHandler = Thread.getDefaultUncaughtExceptionHandler();
        Thread.setDefaultUncaughtExceptionHandler(this);
    }

    @Override
    public void uncaughtException(@NonNull Thread thread, @NonNull Throwable throwable) {
        boolean strictModeThrowable = strictModeHandler.isStrictModeThrowable(throwable);

        // Notify any subscribed clients of the uncaught exception
        Metadata metadata = new Metadata();
        String violationDesc = null;

        if (strictModeThrowable) { // add strictmode policy violation to metadata
            violationDesc = strictModeHandler.getViolationDescription(throwable.getMessage());
            metadata = new Metadata();
            metadata.addMetadata(STRICT_MODE_TAB, STRICT_MODE_KEY, violationDesc);
        }

        String severityReason = strictModeThrowable
                ? SeverityReason.REASON_STRICT_MODE : SeverityReason.REASON_UNHANDLED_EXCEPTION;

        if (strictModeThrowable) { // writes to disk on main thread
            StrictMode.ThreadPolicy originalThreadPolicy = StrictMode.getThreadPolicy();
            StrictMode.setThreadPolicy(StrictMode.ThreadPolicy.LAX);

            client.notifyUnhandledException(throwable,
                    metadata, severityReason, violationDesc);

            StrictMode.setThreadPolicy(originalThreadPolicy);
        } else {
            client.notifyUnhandledException(throwable,
                    metadata, severityReason, null);
        }

        // Pass exception on to original exception handler
        if (originalHandler != null) {
            originalHandler.uncaughtException(thread, throwable);
        } else {
            System.err.printf("Exception in thread \"%s\" ", thread.getName());
            logger.w("Exception", throwable);
        }
    }
}