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

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

/* Use public prototypes only; wrapper provided in module */
extern int test_htmlParseElementInternal(htmlParserCtxtPtr ctxt);

typedef struct {
    int startCount;
    int endCount;
    char lastStart[64];
    char lastEnd[64];
} TestSaxCounters;

static void sax_start(void *ctx, const xmlChar *name, const xmlChar **atts) {
    (void)atts;
    TestSaxCounters *c = (TestSaxCounters *)ctx;
    c->startCount++;
    if (name != NULL) {
        strncpy(c->lastStart, (const char *)name, sizeof(c->lastStart) - 1);
        c->lastStart[sizeof(c->lastStart) - 1] = '\0';
    }
}

static void sax_end(void *ctx, const xmlChar *name) {
    TestSaxCounters *c = (TestSaxCounters *)ctx;
    c->endCount++;
    if (name != NULL) {
        strncpy(c->lastEnd, (const char *)name, sizeof(c->lastEnd) - 1);
        c->lastEnd[sizeof(c->lastEnd) - 1] = '\0';
    }
}

static htmlParserCtxtPtr make_ctxt_with_input(const char *input,
                                              int use_html5,
                                              xmlSAXHandler *sax,
                                              void *user) {
    htmlParserCtxtPtr ctxt = htmlCreatePushParserCtxt(sax, user,
                                                      input,
                                                      (int)strlen(input),
                                                      NULL,
                                                      XML_CHAR_ENCODING_NONE);
    TEST_ASSERT_NOT_NULL_MESSAGE(ctxt, "Failed to create HTML push parser context");
    if (use_html5) {
        ctxt->options |= HTML_PARSE_HTML5;
    }
    return ctxt;
}

void setUp(void) {
    xmlInitParser();
}
void tearDown(void) {
    /* No global cleanup here; libxml cleanup is handled externally if needed */
}

/* Tests */

void test_htmlParseElementInternal_null_context_returns_0(void) {
    int ret = test_htmlParseElementInternal(NULL);
    TEST_ASSERT_EQUAL_INT(0, ret);
}

void test_htmlParseElementInternal_null_input_returns_0(void) {
    htmlParserCtxtPtr ctxt = htmlNewParserCtxt();
    TEST_ASSERT_NOT_NULL(ctxt);
    /* Ensure input is NULL */
    TEST_ASSERT_NULL(ctxt->input);

    int ret = test_htmlParseElementInternal(ctxt);
    TEST_ASSERT_EQUAL_INT(0, ret);

    htmlFreeParserCtxt(ctxt);
}

void test_htmlParseElementInternal_nonempty_tag_returns_1_and_callbacks(void) {
    const char *src = "<div>";
    xmlSAXHandler sax;
    memset(&sax, 0, sizeof(sax));
    sax.startElement = sax_start;
    sax.endElement = sax_end;

    TestSaxCounters counters = {0};
    htmlParserCtxtPtr ctxt = make_ctxt_with_input(src, 0, &sax, &counters);

    int ret = test_htmlParseElementInternal(ctxt);
    TEST_ASSERT_EQUAL_INT(1, ret);
    TEST_ASSERT_EQUAL_INT(1, counters.startCount);
    TEST_ASSERT_EQUAL_INT(0, counters.endCount);
    TEST_ASSERT_EQUAL_STRING("div", counters.lastStart);

    /* Name should remain as current element since not empty */
    TEST_ASSERT_NOT_NULL(ctxt->name);
    TEST_ASSERT_TRUE(xmlStrEqual(ctxt->name, BAD_CAST "div"));

    htmlFreeParserCtxt(ctxt);
}

void test_htmlParseElementInternal_self_closing_non_html5_calls_endElement_and_returns_0(void) {
    const char *src = "<input/>";
    xmlSAXHandler sax;
    memset(&sax, 0, sizeof(sax));
    sax.startElement = sax_start;
    sax.endElement = sax_end;

    TestSaxCounters counters = {0};
    htmlParserCtxtPtr ctxt = make_ctxt_with_input(src, 0, &sax, &counters);

    int ret = test_htmlParseElementInternal(ctxt);
    TEST_ASSERT_EQUAL_INT(0, ret);
    TEST_ASSERT_EQUAL_INT(1, counters.startCount);
    TEST_ASSERT_EQUAL_INT(1, counters.endCount);
    TEST_ASSERT_EQUAL_STRING("input", counters.lastStart);
    TEST_ASSERT_EQUAL_STRING("input", counters.lastEnd);

    htmlFreeParserCtxt(ctxt);
}

void test_htmlParseElementInternal_self_closing_html5_does_not_call_endElement_returns_0(void) {
    const char *src = "<input/>";
    xmlSAXHandler sax;
    memset(&sax, 0, sizeof(sax));
    sax.startElement = sax_start;
    sax.endElement = sax_end;

    TestSaxCounters counters = {0};
    htmlParserCtxtPtr ctxt = make_ctxt_with_input(src, 1, &sax, &counters);

    int ret = test_htmlParseElementInternal(ctxt);
    TEST_ASSERT_EQUAL_INT(0, ret);
    TEST_ASSERT_EQUAL_INT(1, counters.startCount);
    TEST_ASSERT_EQUAL_INT(0, counters.endCount);
    TEST_ASSERT_EQUAL_STRING("input", counters.lastStart);

    htmlFreeParserCtxt(ctxt);
}

void test_htmlParseElementInternal_dtd_empty_without_solidus_returns_0_and_calls_end(void) {
    const char *src = "<br>";
    xmlSAXHandler sax;
    memset(&sax, 0, sizeof(sax));
    sax.startElement = sax_start;
    sax.endElement = sax_end;

    TestSaxCounters counters = {0};
    htmlParserCtxtPtr ctxt = make_ctxt_with_input(src, 0, &sax, &counters);

    int ret = test_htmlParseElementInternal(ctxt);
    TEST_ASSERT_EQUAL_INT(0, ret);
    TEST_ASSERT_EQUAL_INT(1, counters.startCount);
    TEST_ASSERT_EQUAL_INT(1, counters.endCount);
    TEST_ASSERT_EQUAL_STRING("br", counters.lastStart);
    TEST_ASSERT_EQUAL_STRING("br", counters.lastEnd);

    htmlFreeParserCtxt(ctxt);
}

void test_htmlParseElementInternal_missing_gt_returns_0_and_no_callbacks(void) {
    const char *src = "<div";
    xmlSAXHandler sax;
    memset(&sax, 0, sizeof(sax));
    sax.startElement = sax_start;
    sax.endElement = sax_end;

    TestSaxCounters counters = {0};
    htmlParserCtxtPtr ctxt = make_ctxt_with_input(src, 0, &sax, &counters);

    int ret = test_htmlParseElementInternal(ctxt);
    TEST_ASSERT_EQUAL_INT(0, ret);
    TEST_ASSERT_EQUAL_INT(0, counters.startCount);
    TEST_ASSERT_EQUAL_INT(0, counters.endCount);

    htmlFreeParserCtxt(ctxt);
}

void test_htmlParseElementInternal_unknown_tag_keeps_endCheckState_zero_returns_1(void) {
    const char *src = "<custom>";
    xmlSAXHandler sax;
    memset(&sax, 0, sizeof(sax));
    sax.startElement = sax_start;
    sax.endElement = sax_end;

    TestSaxCounters counters = {0};
    htmlParserCtxtPtr ctxt = make_ctxt_with_input(src, 0, &sax, &counters);

    TEST_ASSERT_EQUAL_INT(0, ctxt->endCheckState);
    int ret = test_htmlParseElementInternal(ctxt);
    TEST_ASSERT_EQUAL_INT(1, ret);
    TEST_ASSERT_EQUAL_INT(1, counters.startCount);
    TEST_ASSERT_EQUAL_INT(0, counters.endCount);
    TEST_ASSERT_EQUAL_INT(0, ctxt->endCheckState); /* remains unchanged */

    htmlFreeParserCtxt(ctxt);
}

int main(void) {
    UNITY_BEGIN();
    RUN_TEST(test_htmlParseElementInternal_null_context_returns_0);
    RUN_TEST(test_htmlParseElementInternal_null_input_returns_0);
    RUN_TEST(test_htmlParseElementInternal_nonempty_tag_returns_1_and_callbacks);
    RUN_TEST(test_htmlParseElementInternal_self_closing_non_html5_calls_endElement_and_returns_0);
    RUN_TEST(test_htmlParseElementInternal_self_closing_html5_does_not_call_endElement_returns_0);
    RUN_TEST(test_htmlParseElementInternal_dtd_empty_without_solidus_returns_0_and_calls_end);
    RUN_TEST(test_htmlParseElementInternal_missing_gt_returns_0_and_no_callbacks);
    RUN_TEST(test_htmlParseElementInternal_unknown_tag_keeps_endCheckState_zero_returns_1);
    return UNITY_END();
}