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

#include <libxml/tree.h>
#include <libxml/xmlIO.h>
#include <stdlib.h>
#include <string.h>

/* Wrapper provided in module to access the static function */
void test_htmlAttrDumpOutput(xmlOutputBufferPtr buf, xmlAttrPtr cur);

/* Accumulator for xmlOutputBuffer IO */
typedef struct {
    char *data;
    size_t len;
    size_t cap;
} Accum;

static void Accum_init(Accum *a) {
    a->data = NULL;
    a->len = 0;
    a->cap = 0;
}

static void Accum_free(Accum *a) {
    free(a->data);
    a->data = NULL;
    a->len = 0;
    a->cap = 0;
}

static int acc_write(void *context, const char *buffer, int len) {
    Accum *a = (Accum *)context;
    if (len <= 0)
        return 0;
    size_t need = a->len + (size_t)len + 1; /* +1 for NUL */
    if (need > a->cap) {
        size_t newcap = a->cap ? a->cap : 64;
        while (newcap < need)
            newcap *= 2;
        char *nd = (char *)realloc(a->data, newcap);
        if (nd == NULL)
            return -1;
        a->data = nd;
        a->cap = newcap;
    }
    memcpy(a->data + a->len, buffer, (size_t)len);
    a->len += (size_t)len;
    a->data[a->len] = '\0';
    return len;
}

static int acc_close(void *context) {
    (void)context;
    return 0;
}

static xmlOutputBufferPtr makeOutputBuffer(Accum *a) {
    Accum_init(a);
    xmlOutputBufferPtr buf = xmlOutputBufferCreateIO(acc_write, acc_close, a, NULL);
    return buf;
}

void setUp(void) {
    /* Setup code here, or leave empty */
}

void tearDown(void) {
    /* Cleanup code here, or leave empty */
}

/* Helper to create a simple document and root node */
static void make_doc_and_root(const char *rootName, xmlDocPtr *pdoc, xmlNodePtr *proot) {
    xmlDocPtr doc = xmlNewDoc(BAD_CAST "1.0");
    TEST_ASSERT_NOT_NULL_MESSAGE(doc, "xmlNewDoc failed");
    xmlNodePtr root = xmlNewNode(NULL, BAD_CAST rootName);
    TEST_ASSERT_NOT_NULL_MESSAGE(root, "xmlNewNode failed");
    xmlDocSetRootElement(doc, root);
    *pdoc = doc;
    *proot = root;
}

/* 1) Non-URI attribute with characters requiring HTML escaping */
void test_htmlAttrDumpOutput_basic_escape_text(void) {
    xmlDocPtr doc = NULL;
    xmlNodePtr node = NULL;
    make_doc_and_root("div", &doc, &node);

    xmlAttrPtr attr = xmlNewProp(node, BAD_CAST "title", BAD_CAST "Tom & \"Jerry\"");
    TEST_ASSERT_NOT_NULL(attr);

    Accum acc;
    xmlOutputBufferPtr buf = makeOutputBuffer(&acc);
    TEST_ASSERT_NOT_NULL(buf);

    test_htmlAttrDumpOutput(buf, attr);
    xmlOutputBufferFlush(buf);
    /* Don't use buf after close */
    xmlOutputBufferClose(buf);

    const char *expected = " title=\"Tom &amp; &quot;Jerry&quot;\"";
    TEST_ASSERT_NOT_NULL(acc.data);
    TEST_ASSERT_EQUAL_STRING(expected, acc.data);

    Accum_free(&acc);
    xmlFreeDoc(doc);
}

/* 2) Boolean attribute (lowercase) should serialize without ="..." */
void test_htmlAttrDumpOutput_boolean_selected_lowercase(void) {
    xmlDocPtr doc = NULL;
    xmlNodePtr node = NULL;
    make_doc_and_root("option", &doc, &node);

    xmlAttrPtr attr = xmlNewProp(node, BAD_CAST "selected", BAD_CAST "selected");
    TEST_ASSERT_NOT_NULL(attr);

    Accum acc;
    xmlOutputBufferPtr buf = makeOutputBuffer(&acc);
    TEST_ASSERT_NOT_NULL(buf);

    test_htmlAttrDumpOutput(buf, attr);
    xmlOutputBufferFlush(buf);
    xmlOutputBufferClose(buf);

    const char *expected = " selected";
    TEST_ASSERT_NOT_NULL(acc.data);
    TEST_ASSERT_EQUAL_STRING(expected, acc.data);

    Accum_free(&acc);
    xmlFreeDoc(doc);
}

/* 3) Boolean attribute (uppercase name) should also serialize without ="..." */
void test_htmlAttrDumpOutput_boolean_selected_uppercase(void) {
    xmlDocPtr doc = NULL;
    xmlNodePtr node = NULL;
    make_doc_and_root("option", &doc, &node);

    xmlAttrPtr attr = xmlNewProp(node, BAD_CAST "SELECTED", BAD_CAST "true");
    TEST_ASSERT_NOT_NULL(attr);

    Accum acc;
    xmlOutputBufferPtr buf = makeOutputBuffer(&acc);
    TEST_ASSERT_NOT_NULL(buf);

    test_htmlAttrDumpOutput(buf, attr);
    xmlOutputBufferFlush(buf);
    xmlOutputBufferClose(buf);

    const char *expected = " SELECTED";
    TEST_ASSERT_NOT_NULL(acc.data);
    TEST_ASSERT_EQUAL_STRING(expected, acc.data);

    Accum_free(&acc);
    xmlFreeDoc(doc);
}

/* 4) Attribute with NULL value (no children) should serialize without ="..." */
void test_htmlAttrDumpOutput_null_value_no_children(void) {
    xmlDocPtr doc = NULL;
    xmlNodePtr node = NULL;
    make_doc_and_root("div", &doc, &node);

    xmlAttrPtr attr = xmlNewProp(node, BAD_CAST "data", NULL);
    TEST_ASSERT_NOT_NULL(attr);
    TEST_ASSERT_NULL(attr->children);

    Accum acc;
    xmlOutputBufferPtr buf = makeOutputBuffer(&acc);
    TEST_ASSERT_NOT_NULL(buf);

    test_htmlAttrDumpOutput(buf, attr);
    xmlOutputBufferFlush(buf);
    xmlOutputBufferClose(buf);

    const char *expected = " data";
    TEST_ASSERT_NOT_NULL(acc.data);
    TEST_ASSERT_EQUAL_STRING(expected, acc.data);

    Accum_free(&acc);
    xmlFreeDoc(doc);
}

/* 5) Namespaced attribute: prefix should be printed and value escaped */
void test_htmlAttrDumpOutput_namespaced_attr_with_escape(void) {
    xmlDocPtr doc = NULL;
    xmlNodePtr node = NULL;
    make_doc_and_root("div", &doc, &node);

    xmlNsPtr ns = xmlNewNs(node, BAD_CAST "http://example.com/ns", BAD_CAST "p");
    TEST_ASSERT_NOT_NULL(ns);

    xmlAttrPtr attr = xmlNewNsProp(node, ns, BAD_CAST "id", BAD_CAST "alpha&beta");
    TEST_ASSERT_NOT_NULL(attr);

    Accum acc;
    xmlOutputBufferPtr buf = makeOutputBuffer(&acc);
    TEST_ASSERT_NOT_NULL(buf);

    test_htmlAttrDumpOutput(buf, attr);
    xmlOutputBufferFlush(buf);
    xmlOutputBufferClose(buf);

    const char *expected = " p:id=\"alpha&amp;beta\"";
    TEST_ASSERT_NOT_NULL(acc.data);
    TEST_ASSERT_EQUAL_STRING(expected, acc.data);

    Accum_free(&acc);
    xmlFreeDoc(doc);
}

/* 6) URI attribute (href): leading spaces preserved, spaces encoded as %20; '&' and '\"' escaped */
void test_htmlAttrDumpOutput_uri_href_serialization(void) {
    xmlDocPtr doc = NULL;
    xmlNodePtr node = NULL;
    make_doc_and_root("a", &doc, &node);

    xmlAttrPtr attr = xmlNewProp(node, BAD_CAST "href", BAD_CAST "  Ab c&\"Z");
    TEST_ASSERT_NOT_NULL(attr);

    Accum acc;
    xmlOutputBufferPtr buf = makeOutputBuffer(&acc);
    TEST_ASSERT_NOT_NULL(buf);

    test_htmlAttrDumpOutput(buf, attr);
    xmlOutputBufferFlush(buf);
    xmlOutputBufferClose(buf);

    const char *expected = " href=\"  Ab%20c&amp;&quot;Z\"";
    TEST_ASSERT_NOT_NULL(acc.data);
    TEST_ASSERT_EQUAL_STRING(expected, acc.data);

    Accum_free(&acc);
    xmlFreeDoc(doc);
}

/* 7) Attribute value containing an entity reference node should serialize as &name; */
void test_htmlAttrDumpOutput_entity_ref_in_value(void) {
    xmlDocPtr doc = NULL;
    xmlNodePtr node = NULL;
    make_doc_and_root("div", &doc, &node);

    /* Start with an attribute without children, then build a mixed content value */
    xmlAttrPtr attr = xmlNewProp(node, BAD_CAST "data", NULL);
    TEST_ASSERT_NOT_NULL(attr);

    xmlNodePtr t1 = xmlNewText(BAD_CAST "X");
    xmlNodePtr ref = xmlNewReference(doc, BAD_CAST "copy"); /* &copy; */
    xmlNodePtr t2 = xmlNewText(BAD_CAST "Y");
    TEST_ASSERT_NOT_NULL(t1);
    TEST_ASSERT_NOT_NULL(ref);
    TEST_ASSERT_NOT_NULL(t2);

    /* Attach children to the attribute */
    xmlAddChild((xmlNodePtr)attr, t1);
    xmlAddChild((xmlNodePtr)attr, ref);
    xmlAddChild((xmlNodePtr)attr, t2);

    Accum acc;
    xmlOutputBufferPtr buf = makeOutputBuffer(&acc);
    TEST_ASSERT_NOT_NULL(buf);

    test_htmlAttrDumpOutput(buf, attr);
    xmlOutputBufferFlush(buf);
    xmlOutputBufferClose(buf);

    const char *expected = " data=\"X&copy;Y\"";
    TEST_ASSERT_NOT_NULL(acc.data);
    TEST_ASSERT_EQUAL_STRING(expected, acc.data);

    Accum_free(&acc);
    xmlFreeDoc(doc);
}

int main(void) {
    UNITY_BEGIN();
    RUN_TEST(test_htmlAttrDumpOutput_basic_escape_text);
    RUN_TEST(test_htmlAttrDumpOutput_boolean_selected_lowercase);
    RUN_TEST(test_htmlAttrDumpOutput_boolean_selected_uppercase);
    RUN_TEST(test_htmlAttrDumpOutput_null_value_no_children);
    RUN_TEST(test_htmlAttrDumpOutput_namespaced_attr_with_escape);
    RUN_TEST(test_htmlAttrDumpOutput_uri_href_serialization);
    RUN_TEST(test_htmlAttrDumpOutput_entity_ref_in_value);
    return UNITY_END();
}