#include "unity/unity.h"
#include <libxml/HTMLparser.h>
#include <libxml/parserInternals.h>

#include <stdlib.h>
#include <string.h>

/* Wrapper provided in the module for the static function */
extern int test_htmlParseLookupCommentEnd(htmlParserCtxtPtr ctxt);

static htmlParserCtxtPtr makeCtxtFromString(const char *s) {
    htmlParserCtxtPtr ctxt = htmlNewParserCtxt();
    TEST_ASSERT_NOT_NULL_MESSAGE(ctxt, "htmlNewParserCtxt failed");

    xmlParserInputPtr in = xmlNewStringInputStream((xmlParserCtxtPtr)ctxt, (const xmlChar *)s);
    TEST_ASSERT_NOT_NULL_MESSAGE(in, "xmlNewStringInputStream failed");

    int pushed = inputPush((xmlParserCtxtPtr)ctxt, in);
    TEST_ASSERT_TRUE_MESSAGE(pushed >= 1, "inputPush failed");

    /* Start fresh for each test */
    ctxt->checkIndex = 0;

    return ctxt;
}

void setUp(void) {
    /* No global init required here; contexts are created per-test */
}

void tearDown(void) {
    /* No global teardown needed */
}

/* Minimal valid comment end: <!--> */
void test_htmlParseLookupCommentEnd_simple_end_arrow(void) {
    const char *s = "<!-->";
    htmlParserCtxtPtr ctxt = makeCtxtFromString(s);

    int ret = test_htmlParseLookupCommentEnd(ctxt);
    TEST_ASSERT_EQUAL_INT(2, ret);
    TEST_ASSERT_EQUAL_INT(0, ctxt->checkIndex);

    htmlFreeParserCtxt(ctxt);
}

/* Invalid: <!--!> should not terminate */
void test_htmlParseLookupCommentEnd_bang_invalid(void) {
    const char *s = "<!--!>";
    htmlParserCtxtPtr ctxt = makeCtxtFromString(s);

    int ret = test_htmlParseLookupCommentEnd(ctxt);
    TEST_ASSERT_EQUAL_INT(-1, ret);
    /* The function will have searched and not found a valid end */
    htmlFreeParserCtxt(ctxt);
}

/* Invalid: <!---!> should not terminate */
void test_htmlParseLookupCommentEnd_dash_bang_invalid(void) {
    const char *s = "<!---!>";
    htmlParserCtxtPtr ctxt = makeCtxtFromString(s);

    int ret = test_htmlParseLookupCommentEnd(ctxt);
    TEST_ASSERT_EQUAL_INT(-1, ret);

    htmlFreeParserCtxt(ctxt);
}

/* Valid: <!----!> should terminate at the --!> (offset 4) */
void test_htmlParseLookupCommentEnd_dash_dash_bang_valid(void) {
    const char *s = "<!----!>";
    htmlParserCtxtPtr ctxt = makeCtxtFromString(s);

    int ret = test_htmlParseLookupCommentEnd(ctxt);
    TEST_ASSERT_EQUAL_INT(4, ret);
    TEST_ASSERT_EQUAL_INT(0, ctxt->checkIndex);

    htmlFreeParserCtxt(ctxt);
}

/* Incomplete buffer: "<!--" requires more data, should return -1 and set checkIndex to 2 */
void test_htmlParseLookupCommentEnd_incomplete_needs_more_offset2(void) {
    const char *s = "<!--";
    htmlParserCtxtPtr ctxt = makeCtxtFromString(s);

    int ret = test_htmlParseLookupCommentEnd(ctxt);
    TEST_ASSERT_EQUAL_INT(-1, ret);
    TEST_ASSERT_EQUAL_INT(2, ctxt->checkIndex);

    htmlFreeParserCtxt(ctxt);
}

/* Incomplete buffer after '!': "<!--!" requires more data, should return -1 and set checkIndex to 2 */
void test_htmlParseLookupCommentEnd_incomplete_after_bang(void) {
    const char *s = "<!--!";
    htmlParserCtxtPtr ctxt = makeCtxtFromString(s);

    int ret = test_htmlParseLookupCommentEnd(ctxt);
    TEST_ASSERT_EQUAL_INT(-1, ret);
    TEST_ASSERT_EQUAL_INT(2, ctxt->checkIndex);

    htmlFreeParserCtxt(ctxt);
}

/* Skip non-terminators until a valid "-->" is found: "<!---a-->" should return 6 */
void test_htmlParseLookupCommentEnd_skip_non_terminators_then_close(void) {
    const char *s = "<!---a-->";
    htmlParserCtxtPtr ctxt = makeCtxtFromString(s);

    int ret = test_htmlParseLookupCommentEnd(ctxt);
    TEST_ASSERT_EQUAL_INT(6, ret);
    TEST_ASSERT_EQUAL_INT(0, ctxt->checkIndex);

    htmlFreeParserCtxt(ctxt);
}

/* Skip past a false '!'-sequence, then close: "<!--!x-->" should return 6 */
void test_htmlParseLookupCommentEnd_skip_false_bang_then_close(void) {
    const char *s = "<!--!x-->";
    htmlParserCtxtPtr ctxt = makeCtxtFromString(s);

    int ret = test_htmlParseLookupCommentEnd(ctxt);
    TEST_ASSERT_EQUAL_INT(6, ret);
    TEST_ASSERT_EQUAL_INT(0, ctxt->checkIndex);

    htmlFreeParserCtxt(ctxt);
}

/* No "--" present at all: "<!>" should return -1 */
void test_htmlParseLookupCommentEnd_no_hyphens(void) {
    const char *s = "<!>";
    htmlParserCtxtPtr ctxt = makeCtxtFromString(s);

    int ret = test_htmlParseLookupCommentEnd(ctxt);
    TEST_ASSERT_EQUAL_INT(-1, ret);

    htmlFreeParserCtxt(ctxt);
}

int main(void) {
    UNITY_BEGIN();

    RUN_TEST(test_htmlParseLookupCommentEnd_simple_end_arrow);
    RUN_TEST(test_htmlParseLookupCommentEnd_bang_invalid);
    RUN_TEST(test_htmlParseLookupCommentEnd_dash_bang_invalid);
    RUN_TEST(test_htmlParseLookupCommentEnd_dash_dash_bang_valid);
    RUN_TEST(test_htmlParseLookupCommentEnd_incomplete_needs_more_offset2);
    RUN_TEST(test_htmlParseLookupCommentEnd_incomplete_after_bang);
    RUN_TEST(test_htmlParseLookupCommentEnd_skip_non_terminators_then_close);
    RUN_TEST(test_htmlParseLookupCommentEnd_skip_false_bang_then_close);
    RUN_TEST(test_htmlParseLookupCommentEnd_no_hyphens);

    return UNITY_END();
}