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

#include <libxml/parser.h>
#include <libxml/tree.h>
#include <libxml/xmlmemory.h>
#include <string.h>
#include <stdlib.h>

/* Wrapper for the static function provided in the source module */
extern int test_htmlNodeInfoPush(htmlParserCtxtPtr ctxt, htmlParserNodeInfo *value);

static xmlNodePtr make_dummy_node(const char *name) {
    return xmlNewNode(NULL, (const xmlChar *)name);
}

void setUp(void) {
    xmlInitParser();
}

void tearDown(void) {
    xmlCleanupParser();
}

/* Helper to compare two htmlParserNodeInfo records */
static void assert_nodeinfo_equal(const htmlParserNodeInfo *a, const htmlParserNodeInfo *b) {
    TEST_ASSERT_NOT_NULL(a);
    TEST_ASSERT_NOT_NULL(b);
    TEST_ASSERT_EQUAL_PTR(a->node, b->node);
    TEST_ASSERT_EQUAL_UINT64(a->begin_pos, b->begin_pos);
    TEST_ASSERT_EQUAL_UINT64(a->begin_line, b->begin_line);
    TEST_ASSERT_EQUAL_UINT64(a->end_pos, b->end_pos);
    TEST_ASSERT_EQUAL_UINT64(a->end_line, b->end_line);
}

/* Test: initial allocation when table is NULL and max=0 */
void test_htmlNodeInfoPush_initial_alloc_and_store(void) {
    htmlParserCtxtPtr ctxt = htmlNewParserCtxt();
    TEST_ASSERT_NOT_NULL(ctxt);

    /* Force an empty stack state */
    ctxt->nodeInfoTab = NULL;
    ctxt->nodeInfoMax = 0;
    ctxt->nodeInfoNr = 0;
    ctxt->nodeInfo = NULL;

    xmlNodePtr n1 = make_dummy_node("n1");
    TEST_ASSERT_NOT_NULL(n1);

    htmlParserNodeInfo info1;
    memset(&info1, 0, sizeof(info1));
    info1.node = n1;
    info1.begin_pos = 10;
    info1.begin_line = 2;
    info1.end_pos = 20;
    info1.end_line = 3;

    int ret = test_htmlNodeInfoPush(ctxt, &info1);

    /* ret can be 0 for first element; ensure push succeeded */
    TEST_ASSERT_NOT_NULL(ctxt->nodeInfoTab);
    TEST_ASSERT_TRUE(ctxt->nodeInfoMax > 0);
    TEST_ASSERT_EQUAL_INT(1, ctxt->nodeInfoNr);
    TEST_ASSERT_EQUAL_PTR(&ctxt->nodeInfoTab[0], ctxt->nodeInfo);

    assert_nodeinfo_equal(&info1, &ctxt->nodeInfoTab[0]);

    xmlFreeNode(n1);
    htmlFreeParserCtxt(ctxt);
}

/* Test: push when there is already capacity (no growth path) */
void test_htmlNodeInfoPush_no_growth_needed(void) {
    htmlParserCtxtPtr ctxt = htmlNewParserCtxt();
    TEST_ASSERT_NOT_NULL(ctxt);

    /* Pre-allocate capacity for 4 entries */
    int cap = 4;
    ctxt->nodeInfoTab = (xmlParserNodeInfo *)xmlMalloc(sizeof(ctxt->nodeInfoTab[0]) * cap);
    TEST_ASSERT_NOT_NULL(ctxt->nodeInfoTab);
    ctxt->nodeInfoMax = cap;
    ctxt->nodeInfoNr = 0;
    ctxt->nodeInfo = NULL;

    xmlNodePtr n1 = make_dummy_node("a");
    xmlNodePtr n2 = make_dummy_node("b");
    TEST_ASSERT_NOT_NULL(n1);
    TEST_ASSERT_NOT_NULL(n2);

    htmlParserNodeInfo info1, info2;
    memset(&info1, 0, sizeof(info1));
    memset(&info2, 0, sizeof(info2));
    info1.node = n1; info1.begin_pos = 1; info1.begin_line = 1; info1.end_pos = 2; info1.end_line = 2;
    info2.node = n2; info2.begin_pos = 3; info2.begin_line = 3; info2.end_pos = 4; info2.end_line = 4;

    int ret0 = test_htmlNodeInfoPush(ctxt, &info1);
    TEST_ASSERT_EQUAL_INT(0, ret0);
    TEST_ASSERT_EQUAL_INT(1, ctxt->nodeInfoNr);
    TEST_ASSERT_EQUAL_PTR(&ctxt->nodeInfoTab[0], ctxt->nodeInfo);
    assert_nodeinfo_equal(&info1, &ctxt->nodeInfoTab[0]);

    int ret1 = test_htmlNodeInfoPush(ctxt, &info2);
    TEST_ASSERT_EQUAL_INT(1, ret1);
    TEST_ASSERT_EQUAL_INT(2, ctxt->nodeInfoNr);
    TEST_ASSERT_EQUAL_PTR(&ctxt->nodeInfoTab[1], ctxt->nodeInfo);
    assert_nodeinfo_equal(&info2, &ctxt->nodeInfoTab[1]);

    xmlFreeNode(n1);
    xmlFreeNode(n2);
    htmlFreeParserCtxt(ctxt);
}

/* Test: growth when full and preservation of existing entries */
void test_htmlNodeInfoPush_growth_and_preserve_existing(void) {
    htmlParserCtxtPtr ctxt = htmlNewParserCtxt();
    TEST_ASSERT_NOT_NULL(ctxt);

    /* Capacity 1, already filled with one element */
    ctxt->nodeInfoTab = (xmlParserNodeInfo *)xmlMalloc(sizeof(ctxt->nodeInfoTab[0]) * 1);
    TEST_ASSERT_NOT_NULL(ctxt->nodeInfoTab);
    ctxt->nodeInfoMax = 1;
    ctxt->nodeInfoNr = 1;
    ctxt->nodeInfo = &ctxt->nodeInfoTab[0];

    xmlNodePtr n0 = make_dummy_node("first");
    xmlNodePtr n1 = make_dummy_node("second");
    TEST_ASSERT_NOT_NULL(n0);
    TEST_ASSERT_NOT_NULL(n1);

    htmlParserNodeInfo first, second;
    memset(&first, 0, sizeof(first));
    memset(&second, 0, sizeof(second));
    first.node = n0; first.begin_pos = 10; first.begin_line = 1; first.end_pos = 11; first.end_line = 2;
    second.node = n1; second.begin_pos = 20; second.begin_line = 3; second.end_pos = 21; second.end_line = 4;

    /* Initialize first entry */
    ctxt->nodeInfoTab[0] = first;

    /* Push second; should trigger growth and append at index 1 */
    int ret = test_htmlNodeInfoPush(ctxt, &second);
    TEST_ASSERT_EQUAL_INT(1, ret);
    TEST_ASSERT_TRUE(ctxt->nodeInfoMax > 1);
    TEST_ASSERT_EQUAL_INT(2, ctxt->nodeInfoNr);
    TEST_ASSERT_NOT_NULL(ctxt->nodeInfoTab);
    TEST_ASSERT_EQUAL_PTR(&ctxt->nodeInfoTab[1], ctxt->nodeInfo);

    assert_nodeinfo_equal(&first, &ctxt->nodeInfoTab[0]);
    assert_nodeinfo_equal(&second, &ctxt->nodeInfoTab[1]);

    xmlFreeNode(n0);
    xmlFreeNode(n1);
    htmlFreeParserCtxt(ctxt);
}

/* Test: multiple pushes to ensure repeated growth and correct indexing */
void test_htmlNodeInfoPush_multiple_pushes(void) {
    htmlParserCtxtPtr ctxt = htmlNewParserCtxt();
    TEST_ASSERT_NOT_NULL(ctxt);

    /* Start with an empty stack */
    ctxt->nodeInfoTab = NULL;
    ctxt->nodeInfoMax = 0;
    ctxt->nodeInfoNr = 0;
    ctxt->nodeInfo = NULL;

    const int count = 100;
    xmlNodePtr nodes[count];

    for (int i = 0; i < count; i++) {
        nodes[i] = make_dummy_node("x");
        TEST_ASSERT_NOT_NULL(nodes[i]);

        htmlParserNodeInfo info;
        memset(&info, 0, sizeof(info));
        info.node = nodes[i];
        info.begin_pos = (unsigned long)i;
        info.begin_line = (unsigned long)(i + 1);
        info.end_pos = (unsigned long)(2 * i);
        info.end_line = (unsigned long)(2 * i + 1);

        int ret = test_htmlNodeInfoPush(ctxt, &info);
        TEST_ASSERT_EQUAL_INT(i, ret);
        TEST_ASSERT_EQUAL_INT(i + 1, ctxt->nodeInfoNr);

        /* Verify the just-pushed element */
        assert_nodeinfo_equal(&info, &ctxt->nodeInfoTab[i]);
        TEST_ASSERT_EQUAL_PTR(&ctxt->nodeInfoTab[i], ctxt->nodeInfo);
    }

    TEST_ASSERT_TRUE(ctxt->nodeInfoMax >= ctxt->nodeInfoNr);
    TEST_ASSERT_EQUAL_INT(count, ctxt->nodeInfoNr);

    /* Cleanup created nodes */
    for (int i = 0; i < count; i++) {
        xmlFreeNode(nodes[i]);
    }
    htmlFreeParserCtxt(ctxt);
}

int main(void) {
    UNITY_BEGIN();
    RUN_TEST(test_htmlNodeInfoPush_initial_alloc_and_store);
    RUN_TEST(test_htmlNodeInfoPush_no_growth_needed);
    RUN_TEST(test_htmlNodeInfoPush_growth_and_preserve_existing);
    RUN_TEST(test_htmlNodeInfoPush_multiple_pushes);
    return UNITY_END();
}