/*
 * Copyright (C) 2009 Julien Peeters
 * Copyright (C) 2017-2018 Michael Gratton <mike@vee.net>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.

 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.

 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
 *
 * Author:
 *  Julien Peeters <contact@julienpeeters.fr>
 *  Michael Gratton <mike@vee.net>
 */


public void assert_null(Object? actual, string? context = null)
    throws Error {
    if (actual != null) {
        print_assert(context ?? "Object is non-null", null);
        assert_not_reached();
    }
}

public void assert_non_null(Object? actual, string? context = null)
    throws Error {
    if (actual == null) {
        print_assert(context ?? "Object is null", null);
        assert_not_reached();
    }
}

public void assert_equal(Object expected, Object? actual, string? context = null)
    throws Error {
    if (expected != actual) {
        print_assert(context ?? "Objects are not equal", null);
        assert_not_reached();
    }
}

public void assert_string(string expected, string? actual, string? context = null)
    throws Error {
    if (expected != actual) {
        string a = expected;
        if (a.length > 32) {
            a = a[0:32] + "…";
        }
        string b = actual;
        if (b.length > 32) {
            b = b[0:32] + "…";
        }
        print_assert("Expected: \"%s\", was: \"%s\"".printf(a, b), context);
        assert_not_reached();
    }
}

public void assert_null_string(string? actual, string? context = null)
    throws Error {
    if (actual != null) {
        string a = actual;
        if (a.length > 70) {
            a = a[0:70] + "…";
        }
        print_assert("Expected: null, was: \"%s\"".printf(a), context);
        assert_not_reached();
    }
}

public void assert_int(int expected, int actual, string? context = null)
    throws Error {
    if (expected != actual) {
        print_assert("Expected: %d, was: %d".printf(expected, actual), context);
        assert_not_reached();
    }
}

public void assert_true(bool condition, string? context = null)
    throws Error {
    if (!condition) {
        print_assert(context ?? "Expected true", null);
        assert_not_reached();
    }
}

public void assert_false(bool condition, string? context = null)
    throws Error {
    if (condition) {
        print_assert(context ?? "Expected false", null);
        assert_not_reached();
    }
}

public void assert_error(Error expected, Error? actual, string? context = null) {
    bool failed = false;
    if (actual == null) {
        print_assert(
            "Expected error: %s %i, was null".printf(
                expected.domain.to_string(), expected.code
            ),
            context
        );
        failed = true;
    } else if (expected.domain != actual.domain ||
               expected.code != actual.code) {
        print_assert(
            "Expected error: %s %i, was actually %s %i: %s".printf(
                expected.domain.to_string(),
                expected.code,
                actual.domain.to_string(),
                actual.code,
                actual.message
            ),
            context
        );
        failed = true;
    }

    if (failed) {
        assert_not_reached();
    }
}

// XXX this shadows GLib.assert_no_error since that doesn't work
public void assert_no_error(Error? err, string? context = null) {
    if (err != null) {
        print_assert(
            "Unexpected error: %s %i: %s".printf(
                err.domain.to_string(),
                err.code,
                err.message
            ),
            context
        );
        assert_not_reached();
    }
}

private inline void print_assert(string message, string? context) {
    string output = message;
    if (context != null) {
        output = "%s: %s".printf(context, output);
    }
    GLib.stderr.puts(output);
    GLib.stderr.putc('\n');
}


public abstract class TestCase : Object {


    /** GLib.File URI for resources in test/data. */
    public const string RESOURCE_URI = "resource:///org/gnome/GearyTest";


    private class SignalWaiter : Object {

        public bool was_fired = false;

        public void @callback(Object source) {
            was_fired = true;
        }
    }


    protected MainContext main_loop = MainContext.default();

	private GLib.TestSuite suite;
	private Adaptor[] adaptors = new Adaptor[0];
    private AsyncQueue<AsyncResult> async_results = new AsyncQueue<AsyncResult>();

	public delegate void TestMethod() throws Error;

	public TestCase(string name) {
		this.suite = new GLib.TestSuite(name);
	}

	public void add_test(string name, owned TestMethod test) {
		var adaptor = new Adaptor(name, (owned) test, this);
		this.adaptors += adaptor;

		this.suite.add(
            new GLib.TestCase(
                adaptor.name,
                adaptor.set_up,
                adaptor.run,
                adaptor.tear_down
            )
        );
	}

	public virtual void set_up() throws Error {
	}

	public virtual void tear_down() throws Error {
	}

	public GLib.TestSuite get_suite() {
		return this.suite;
	}

    protected void async_complete(AsyncResult result) {
        this.async_results.push(result);
        // notify the loop so that if async_result() has already been
        // called, that method won't block
        this.main_loop.wakeup();
    }

    protected AsyncResult async_result() {
        AsyncResult? result = null;
        while (result == null) {
            this.main_loop.iteration(true);
            result = this.async_results.try_pop();
        }
        return result;
    }

    /**
     * Waits for a mock object's call to be completed.
     *
     * This method busy waits on the test's main loop until either
     * until {@link ExpectedCall.was_called} is true, or until the
     * given timeout in seconds has occurred.
     *
     * Returns //true// if the call was made, or //false// if the
     * timeout was reached.
     */
    protected bool wait_for_call(ExpectedCall call, double timeout = 1.0) {
        GLib.Timer timer = new GLib.Timer();
        timer.start();
        while (!call.was_called && timer.elapsed() < timeout) {
            this.main_loop.iteration(false);
        }
        return call.was_called;
    }

    /**
     * Waits for an object's signal to be fired.
     *
     * This method busy waits on the test's main loop until either
     * until the object emits the named signal, or until the given
     * timeout in seconds has occurred.
     *
     * Returns //true// if the signal was fired, or //false// if the
     * timeout was reached.
     */
    protected bool wait_for_signal(Object source, string name, double timeout = 0.5) {
        SignalWaiter handler = new SignalWaiter();
        ulong id = GLib.Signal.connect_swapped(
            source, name, (GLib.Callback) handler.callback, handler
        );

        GLib.Timer timer = new GLib.Timer();
        timer.start();
        while (!handler.was_fired && timer.elapsed() < timeout) {
            this.main_loop.iteration(false);
        }

        source.disconnect(id);
        return handler.was_fired;
    }

	private class Adaptor {

		public string name { get; private set; }
		private TestMethod test;
		private TestCase test_case;

		public Adaptor(string name,
                       owned TestMethod test,
                       TestCase test_case) {
			this.name = name;
			this.test = (owned) test;
			this.test_case = test_case;
		}

		public void set_up(void* fixture) {
            try {
                this.test_case.set_up();
            } catch (Error err) {
                assert_no_error(err);
            }
		}

		public void run(void* fixture) {
            try {
                this.test();
            } catch (Error err) {
                assert_no_error(err);
            }
		}

		public void tear_down(void* fixture) {
            try {
                this.test_case.tear_down();
            } catch (Error err) {
                assert_no_error(err);
            }
		}
	}
}