/*

	9unit
	Copyright (C) Jonathan Lamothe <jonathan@jlamothe.net>

	This program 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 3 of the
	License, or (at your option) any later version.

	This program 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 program.  If not, see
	<http://www.gnu.org/licenses/>.

*/

#include <u.h>
#include <libc.h>
#include <stdio.h>

#include "9unit.h"

// Internal Types

// data required by the context management functions
typedef struct ContextData ContextData;

// data required to run a single test with a label
typedef struct SingleTestContext SingleTestContext;

// data used by check_value()
typedef struct CheckValueData CheckValueData;

struct ContextData
{
	const char *old_c; // previous context
	const char *old_fc; // previous full context
	const char *new_c; // new context
	char *new_fc; // new full context
};

struct SingleTestContext
{
	void *ptr; // the state's previous ptr value
	TestResult (*test)(TestState *); // the test to run
};

struct CheckValueData
{
	void *ptr; // state's original ptr value
	void *chk_val; // the value being checked
	void *ref_val; // the reference value
	void (*test)(TestState *, void *, void *); // the test
};

// Internal Prototypes

static void init_TestState(TestState *);
static void print_log(TestState *);
static void clear_log(TestState *);
static void reindex(TestState *);
static void report(const char *);
static void build_new_context(TestState *, ContextData *);
static void display_context(TestState *);
static void restore_context(TestState *, ContextData *);
static void run_single_test_context(TestState *);
static void check_value_test(TestState *);

// Public Functions

void
run_test(TestState *s, TestResult (*t)(TestState *))
{
	if (!s) return;
	s->run++;

	// a null test function is a pending test
	if (!t)
	{
		s->pending++;
		return;
	}

	switch ((*t)(s))
	{
	case test_success:
		s->passed++;
		break;
	case test_failure:
		s->failed++;
		break;
	case test_pending:
		s->pending++;
		break;
	default:
		exits("test returned an invalid response");
	}
}

void
run_tests(void (*tests)(TestState *))
{
	if (!tests) return;
	TestState s;
	memset(&s, 0, sizeof(TestState));
	s.report = report;
	(*tests)(&s);
	print_log(&s);
	printf("Tests run: %d\n", s.run);
	printf("Tests passed: %d\n", s.passed);
	printf("Tests failed: %d\n", s.failed);
	printf("Tests pending: %d\n", s.pending);
	clear_log(&s);
	if (s.failed) exits("test(s) failed");
}

void
append_test_log(TestState *s, const char *msg)
{
	if (!(s && msg)) return;

	// build a new entry:
	TestLogEntry *entry = malloc(sizeof(TestLogEntry));
	entry->text = malloc(strlen(msg) + 1);
	strcpy(entry->text, msg);
	entry->next = 0;

	// add it to the list:
	if (!s->last_log)
	{
		if (s->first_log) // no last entry but we have a first?
		{
			reindex(s);
			s->last_log->next = entry;
		}
		else s->first_log = entry;
	}
	else // there's already a last entry
	{
		if (!s->first_log) // no first entry but we have a last?
			reindex(s); // do our best to fix that
		s->last_log->next = entry;
	}
	s->last_log = entry;
}

void
test_context(
	TestState *s,
	const char *label,
	void (*test)(TestState *)
)
{
	if (!(s && test)) return;
	if (label)
	{
		ContextData cd;
		cd.new_c = label;
		build_new_context(s, &cd);
		display_context(s);
		(*test)(s);
		restore_context(s, &cd);
	}
	else (*test)(s);
}

void
single_test_context(
	TestState *s,
	const char *label,
	TestResult (*test)(TestState *)
)
{
	if (!s) return;
	SingleTestContext stc;
	stc.ptr = s->ptr;
	stc.test = test;
	s->ptr = &stc;
	test_context(s, label, run_single_test_context);
}

void check_value(
	TestState *s,
	const char *context,
	void (*test)(TestState *, void *, void *),
	void *chk_val,
	void *ref_val
)
{
	if (!(s && test)) return;
	CheckValueData d;
	d.ptr = s->ptr;
	d.chk_val = chk_val;
	d.ref_val = ref_val;
	d.test = test;
	s->ptr = &d;
	test_context(s, context, check_value_test);
}

// Internal Functions

static void
print_log(TestState *s)
{
	if (!s) return;
	TestLogEntry *e = s->first_log;
	while(e)
	{
		if(e->text) printf("%s\n", e->text);
		else print("(empty message)\n");
		e = e->next;
	}
}

static void
clear_log(TestState *s)
{
	if (!s) return;
	if(s->last_log && !s->first_log) reindex(s); // fix if broken
	TestLogEntry *e = s->first_log, *next;
	s->first_log = 0;
	s->last_log = 0;
	while (e)
	{
		next = e->next;
		free(e->text);
		free(e);
		e = next;
	}
}

static void
reindex(TestState *s)
{
	if (!s) return;
	if (s->first_log)
	{
		TestLogEntry *e = s->first_log;
		while (e)
		{
			s->last_log = e;
			e = e->next;
		}
	}
	else if (s->last_log) // we have a last log but no first?
	{
		s->first_log = s->last_log;
		fprint(2, "potential memory leak in test log\n");
	}
}

static void
report(const char *str)
{
	print("%s", str);
}

static void
build_new_context(TestState *s, ContextData *cd)
{
	cd->old_c = s->context;
	cd->old_fc = s->full_context;
	if (s->full_context)
	{
		cd->new_fc = malloc(strlen(cd->old_fc) + strlen(cd->new_c) + 3);
		sprintf(cd->new_fc, "%s: %s", cd->old_fc, cd->new_c);
	}
	else
	{
		cd->new_fc = malloc(strlen(cd->new_c) + 1);
		strcpy(cd->new_fc, cd->new_c);
	}
	s->context = cd->new_c;
	s->full_context = cd->new_fc;
	s->depth++;
}

static void
display_context(TestState *s)
{
	for (int i = 1; i < s->depth; i++)
		s->report("\t");
	s->report(s->context);
	s->report("\n");
}

static void
restore_context(TestState *s, ContextData *cd)
{
	s->context = cd->old_c;
	s->full_context = cd->old_fc;
	s->depth--;
	free(cd->new_fc);
}

static void
run_single_test_context(TestState *s)
{
	SingleTestContext *stc = s->ptr;
	s->ptr = stc->ptr;
	run_test(s, stc->test);
}

static void
check_value_test(TestState *s)
{
	CheckValueData *d = s->ptr;
	s->ptr = d->ptr;
	(*d->test)(s, d->chk_val, d->ref_val);
}

//jl