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

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

/* Wrapper provided in the module for calling the static function */
int test_htmlParseLookupGt(xmlParserCtxtPtr ctxt);

/* Unity hooks */
void setUp(void) {
    /* No per-test setup needed */
}
void tearDown(void) {
    /* No per-test teardown needed */
}

/* Helper to create an HTML parser context from a C string */
static htmlParserCtxtPtr make_ctx(const char *s) {
    int len = (int)strlen(s);
    htmlParserCtxtPtr ctxt = htmlCreateMemoryParserCtxt(s, len);
    TEST_ASSERT_NOT_NULL_MESSAGE(ctxt, "Failed to create HTML parser context");
    TEST_ASSERT_NOT_NULL_MESSAGE(ctxt->input, "Parser input is NULL");
    /* Ensure cur starts at the beginning of the buffer for our tests */
    if (ctxt->input->base != NULL)
        ctxt->input->cur = ctxt->input->base;
    return ctxt;
}

/* Basic tag: should find '>' immediately */
void test_htmlParseLookupGt_basic_tag(void) {
    htmlParserCtxtPtr ctxt = make_ctx("<a>");
    ctxt->checkIndex = 0;
    ctxt->endCheckState = 0;

    int ret = test_htmlParseLookupGt(ctxt);
    TEST_ASSERT_EQUAL_INT(0, ret);
    TEST_ASSERT_EQUAL_UINT(0, ctxt->checkIndex);
    TEST_ASSERT_EQUAL_INT(0, ctxt->endCheckState);

    htmlFreeParserCtxt(ctxt);
}

/* Tag with attributes and spaces before closing '>' */
void test_htmlParseLookupGt_attrs_and_spaces(void) {
    htmlParserCtxtPtr ctxt = make_ctx("<a href=\"test\" >");
    ctxt->checkIndex = 0;
    ctxt->endCheckState = 0;

    int ret = test_htmlParseLookupGt(ctxt);
    TEST_ASSERT_EQUAL_INT(0, ret);
    TEST_ASSERT_EQUAL_UINT(0, ctxt->checkIndex);
    TEST_ASSERT_EQUAL_INT(0, ctxt->endCheckState);

    htmlFreeParserCtxt(ctxt);
}

/* '>' inside single-quoted attribute value must not terminate the tag */
void test_htmlParseLookupGt_gt_inside_single_quotes(void) {
    htmlParserCtxtPtr ctxt = make_ctx("<a title='> not end' data='x'>");
    ctxt->checkIndex = 0;
    ctxt->endCheckState = 0;

    int ret = test_htmlParseLookupGt(ctxt);
    TEST_ASSERT_EQUAL_INT(0, ret);
    TEST_ASSERT_EQUAL_UINT(0, ctxt->checkIndex);
    TEST_ASSERT_EQUAL_INT(0, ctxt->endCheckState);

    htmlFreeParserCtxt(ctxt);
}

/* '>' inside double-quoted attribute value must not terminate the tag */
void test_htmlParseLookupGt_gt_inside_double_quotes(void) {
    htmlParserCtxtPtr ctxt = make_ctx("<a title=\"> not end\" data=\"x\">");
    ctxt->checkIndex = 0;
    ctxt->endCheckState = 0;

    int ret = test_htmlParseLookupGt(ctxt);
    TEST_ASSERT_EQUAL_INT(0, ret);
    TEST_ASSERT_EQUAL_UINT(0, ctxt->checkIndex);
    TEST_ASSERT_EQUAL_INT(0, ctxt->endCheckState);

    htmlFreeParserCtxt(ctxt);
}

/* Incomplete tag: no closing '>' in buffer */
void test_htmlParseLookupGt_incomplete_no_gt(void) {
    const char *buf = "<a href='incomplete'";
    htmlParserCtxtPtr ctxt = make_ctx(buf);
    ctxt->checkIndex = 0;
    ctxt->endCheckState = 0;

    size_t expectedIndex = (size_t)(ctxt->input->end - ctxt->input->cur);

    int ret = test_htmlParseLookupGt(ctxt);
    TEST_ASSERT_EQUAL_INT(-1, ret);
    TEST_ASSERT_EQUAL_size_t(expectedIndex, ctxt->checkIndex);
    /* endCheckState is implementation-defined but should be preserved and non-negative */
    TEST_ASSERT_TRUE(ctxt->endCheckState >= 0);

    htmlFreeParserCtxt(ctxt);
}

/* Repeated call on the same incomplete buffer should be idempotent */
void test_htmlParseLookupGt_incomplete_repeat_call_stable(void) {
    const char *buf = "<a href='x' attr=y";
    htmlParserCtxtPtr ctxt = make_ctx(buf);
    ctxt->checkIndex = 0;
    ctxt->endCheckState = 0;

    size_t expectedIndex = (size_t)(ctxt->input->end - ctxt->input->cur);

    int ret1 = test_htmlParseLookupGt(ctxt);
    TEST_ASSERT_EQUAL_INT(-1, ret1);
    int savedState = ctxt->endCheckState;
    size_t savedIndex = ctxt->checkIndex;

    int ret2 = test_htmlParseLookupGt(ctxt);
    TEST_ASSERT_EQUAL_INT(-1, ret2);
    TEST_ASSERT_EQUAL_size_t(expectedIndex, ctxt->checkIndex);
    TEST_ASSERT_EQUAL_size_t(savedIndex, ctxt->checkIndex);
    TEST_ASSERT_EQUAL_INT(savedState, ctxt->endCheckState);

    htmlFreeParserCtxt(ctxt);
}

/* Resume scanning across buffers: first incomplete, then complete */
void test_htmlParseLookupGt_resume_scanning_across_buffers(void) {
    const char *part1 = "<a href='value'";
    const char *part2 = "<a href='value' data=x>";

    /* First, incomplete buffer */
    htmlParserCtxtPtr ctxt1 = make_ctx(part1);
    ctxt1->checkIndex = 0;
    ctxt1->endCheckState = 0;

    int ret1 = test_htmlParseLookupGt(ctxt1);
    TEST_ASSERT_EQUAL_INT(-1, ret1);
    size_t savedIndex = ctxt1->checkIndex;
    int savedState = ctxt1->endCheckState;

    htmlFreeParserCtxt(ctxt1);

    /* Now, new buffer that continues and closes the tag */
    htmlParserCtxtPtr ctxt2 = make_ctx(part2);
    ctxt2->checkIndex = savedIndex;      /* resume offset */
    ctxt2->endCheckState = savedState;   /* resume state */

    int ret2 = test_htmlParseLookupGt(ctxt2);
    TEST_ASSERT_EQUAL_INT(0, ret2);
    TEST_ASSERT_EQUAL_UINT(0, ctxt2->checkIndex);
    TEST_ASSERT_EQUAL_INT(0, ctxt2->endCheckState);

    htmlFreeParserCtxt(ctxt2);
}

/* Closing tag should be handled correctly */
void test_htmlParseLookupGt_closing_tag(void) {
    htmlParserCtxtPtr ctxt = make_ctx("</div>");
    ctxt->checkIndex = 0;
    ctxt->endCheckState = 0;

    int ret = test_htmlParseLookupGt(ctxt);
    TEST_ASSERT_EQUAL_INT(0, ret);
    TEST_ASSERT_EQUAL_UINT(0, ctxt->checkIndex);
    TEST_ASSERT_EQUAL_INT(0, ctxt->endCheckState);

    htmlFreeParserCtxt(ctxt);
}

/* Self-closing tag with '/' before '>' */
void test_htmlParseLookupGt_self_closing(void) {
    htmlParserCtxtPtr ctxt = make_ctx("<img alt='x'/>");
    ctxt->checkIndex = 0;
    ctxt->endCheckState = 0;

    int ret = test_htmlParseLookupGt(ctxt);
    TEST_ASSERT_EQUAL_INT(0, ret);
    TEST_ASSERT_EQUAL_UINT(0, ctxt->checkIndex);
    TEST_ASSERT_EQUAL_INT(0, ctxt->endCheckState);

    htmlFreeParserCtxt(ctxt);
}

int main(void) {
    UNITY_BEGIN();
    xmlInitParser();

    RUN_TEST(test_htmlParseLookupGt_basic_tag);
    RUN_TEST(test_htmlParseLookupGt_attrs_and_spaces);
    RUN_TEST(test_htmlParseLookupGt_gt_inside_single_quotes);
    RUN_TEST(test_htmlParseLookupGt_gt_inside_double_quotes);
    RUN_TEST(test_htmlParseLookupGt_incomplete_no_gt);
    RUN_TEST(test_htmlParseLookupGt_incomplete_repeat_call_stable);
    RUN_TEST(test_htmlParseLookupGt_resume_scanning_across_buffers);
    RUN_TEST(test_htmlParseLookupGt_closing_tag);
    RUN_TEST(test_htmlParseLookupGt_self_closing);

    xmlCleanupParser();
    return UNITY_END();
}