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

#include <string.h>
#include <stdio.h>

/* The wrapper for the static function is provided in the module:
   void test_htmlParseEndTag(htmlParserCtxtPtr ctxt); */
void test_htmlParseEndTag(htmlParserCtxtPtr ctxt);

/* Test SAX data capture */
typedef struct {
    int end_count;
    int char_count;
    int comment_count;
    char last_end_name[128];
    char last_chars[256];
    char last_comment[256];
} TestSAXData;

static TestSAXData gSAXData;

static void cb_endElement(void *ctx, const xmlChar *name) {
    TestSAXData *d = (TestSAXData *)ctx;
    d->end_count++;
    if (name) {
        size_t n = strlen((const char *)name);
        if (n >= sizeof(d->last_end_name)) n = sizeof(d->last_end_name) - 1;
        memcpy(d->last_end_name, name, n);
        d->last_end_name[n] = '\0';
    }
}

static void cb_characters(void *ctx, const xmlChar *ch, int len) {
    TestSAXData *d = (TestSAXData *)ctx;
    d->char_count++;
    if (ch && len > 0) {
        size_t n = (size_t)len;
        if (n >= sizeof(d->last_chars)) n = sizeof(d->last_chars) - 1;
        memcpy(d->last_chars, ch, n);
        d->last_chars[n] = '\0';
    } else {
        d->last_chars[0] = '\0';
    }
}

static void cb_comment(void *ctx, const xmlChar *value) {
    TestSAXData *d = (TestSAXData *)ctx;
    d->comment_count++;
    if (value) {
        size_t n = strlen((const char *)value);
        if (n >= sizeof(d->last_comment)) n = sizeof(d->last_comment) - 1;
        memcpy(d->last_comment, value, n);
        d->last_comment[n] = '\0';
    } else {
        d->last_comment[0] = '\0';
    }
}

static xmlSAXHandler gSAX;

/* Helpers */

static void reset_sax_data(void) {
    memset(&gSAXData, 0, sizeof(gSAXData));
    gSAXData.last_end_name[0] = '\0';
    gSAXData.last_chars[0] = '\0';
    gSAXData.last_comment[0] = '\0';
}

static htmlParserCtxtPtr make_ctxt_with_input(const char *text, int options) {
    htmlParserCtxtPtr ctxt = htmlNewParserCtxt();
    TEST_ASSERT_NOT_NULL(ctxt);

    ctxt->options = options;
    ctxt->sax = &gSAX;
    ctxt->userData = &gSAXData;
    ctxt->disableSAX = 0;

    if (ctxt->dict == NULL) {
        ctxt->dict = xmlDictCreate();
        TEST_ASSERT_NOT_NULL(ctxt->dict);
    }

    xmlParserInputPtr in = xmlNewInputStream(ctxt);
    TEST_ASSERT_NOT_NULL(in);

    size_t len = strlen(text);
    xmlChar *buf = xmlStrndup((const xmlChar *)text, (int)len);
    TEST_ASSERT_NOT_NULL(buf);

    in->base = buf;
    in->cur = buf;
    in->end = buf + len;
    in->line = 1;
    in->col = 1;
    in->consumed = 0;

    inputPush(ctxt, in);
    return ctxt;
}

static void ensure_name_stack(htmlParserCtxtPtr ctxt, const char **names, int count) {
    if ((ctxt->nameTab == NULL) || (ctxt->nameMax < count)) {
        if (ctxt->nameTab != NULL) {
            xmlFree((void *)ctxt->nameTab);
        }
        ctxt->nameTab = (const xmlChar **)xmlMalloc(sizeof(xmlChar *) * (count > 0 ? count : 1));
        TEST_ASSERT_NOT_NULL(ctxt->nameTab);
        ctxt->nameMax = (count > 0 ? count : 1);
    }
    for (int i = 0; i < count; i++) {
        ctxt->nameTab[i] = (const xmlChar *)names[i]; /* use string literals */
    }
    ctxt->nameNr = count;
    ctxt->name = (count > 0) ? ctxt->nameTab[count - 1] : NULL;
}

/* Unity setup/teardown */

void setUp(void) {
    reset_sax_data();
}

void tearDown(void) {
    /* nothing */
}

static void init_sax(void) {
    memset(&gSAX, 0, sizeof(gSAX));
    gSAX.endElement = cb_endElement;
    gSAX.characters = cb_characters;
    gSAX.comment = cb_comment;
}

/* Tests */

void test_htmlParseEndTag_eof_after_slash_emits_literal_chars(void) {
    init_sax();
    htmlParserCtxtPtr ctxt = make_ctxt_with_input("</", 0);

    test_htmlParseEndTag(ctxt);

    TEST_ASSERT_EQUAL_INT(1, gSAXData.char_count);
    TEST_ASSERT_EQUAL_STRING("</", gSAXData.last_chars);
    TEST_ASSERT_EQUAL_INT(0, gSAXData.end_count);
    TEST_ASSERT_EQUAL_INT(0, gSAXData.comment_count);

    htmlFreeParserCtxt(ctxt);
}

void test_htmlParseEndTag_immediate_gt_noop(void) {
    init_sax();
    htmlParserCtxtPtr ctxt = make_ctxt_with_input("</>", 0);

    test_htmlParseEndTag(ctxt);

    TEST_ASSERT_EQUAL_INT(0, gSAXData.char_count);
    TEST_ASSERT_EQUAL_INT(0, gSAXData.end_count);
    TEST_ASSERT_EQUAL_INT(0, gSAXData.comment_count);

    htmlFreeParserCtxt(ctxt);
}

void test_htmlParseEndTag_bogus_comment_non_letter(void) {
    init_sax();
    htmlParserCtxtPtr ctxt = make_ctxt_with_input("</123abc>", 0);

    test_htmlParseEndTag(ctxt);

    TEST_ASSERT_EQUAL_INT(1, gSAXData.comment_count);
    TEST_ASSERT_EQUAL_STRING("123abc", gSAXData.last_comment);
    TEST_ASSERT_EQUAL_INT(0, gSAXData.end_count);

    htmlFreeParserCtxt(ctxt);
}

void test_htmlParseEndTag_html5_simple_lowercase_name(void) {
    init_sax();
    htmlParserCtxtPtr ctxt = make_ctxt_with_input("</DiV>", HTML_PARSE_HTML5);

    test_htmlParseEndTag(ctxt);

    TEST_ASSERT_EQUAL_INT(1, gSAXData.end_count);
    TEST_ASSERT_EQUAL_STRING("div", gSAXData.last_end_name);
    TEST_ASSERT_EQUAL_INT(0, gSAXData.comment_count);

    htmlFreeParserCtxt(ctxt);
}

void test_htmlParseEndTag_html5_with_attrs_and_solidus(void) {
    init_sax();
    htmlParserCtxtPtr ctxt = make_ctxt_with_input("</SPAN class=foo />", HTML_PARSE_HTML5);

    test_htmlParseEndTag(ctxt);

    TEST_ASSERT_EQUAL_INT(1, gSAXData.end_count);
    TEST_ASSERT_EQUAL_STRING("span", gSAXData.last_end_name);

    htmlFreeParserCtxt(ctxt);
}

void test_htmlParseEndTag_nonhtml5_special_depth_decrement(void) {
    init_sax();
    htmlParserCtxtPtr ctxt = make_ctxt_with_input("</body>", 0);
    ctxt->depth = 3;

    test_htmlParseEndTag(ctxt);

    TEST_ASSERT_EQUAL_INT(2, ctxt->depth);
    TEST_ASSERT_EQUAL_INT(0, gSAXData.end_count);
    TEST_ASSERT_EQUAL_INT(0, gSAXData.comment_count);

    htmlFreeParserCtxt(ctxt);
}

void test_htmlParseEndTag_nonhtml5_name_not_in_stack_reports_error_and_returns(void) {
    init_sax();
    htmlParserCtxtPtr ctxt = make_ctxt_with_input("</table>", 0);

    /* Prepare a stack that doesn't include "table" */
    const char *stack[] = { "p", "div" };
    ensure_name_stack(ctxt, stack, 2);

    test_htmlParseEndTag(ctxt);

    /* We cannot reliably assert error structures here, but endElement must not be called. */
    TEST_ASSERT_EQUAL_INT(0, gSAXData.end_count);

    htmlFreeParserCtxt(ctxt);
}

void test_htmlParseEndTag_nonhtml5_matching_close_emits_end_and_pops(void) {
    init_sax();
    htmlParserCtxtPtr ctxt = make_ctxt_with_input("</EM>", 0);

    const char *stack[] = { "em" };
    ensure_name_stack(ctxt, stack, 1);
    int before = ctxt->nameNr;

    test_htmlParseEndTag(ctxt);

    TEST_ASSERT_EQUAL_INT(1, gSAXData.end_count);
    TEST_ASSERT_EQUAL_STRING("em", gSAXData.last_end_name);
    /* name stack should have been popped by htmlnamePop */
    TEST_ASSERT_TRUE(ctxt->nameNr == before - 1);

    htmlFreeParserCtxt(ctxt);
}

/* Main */

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

    RUN_TEST(test_htmlParseEndTag_eof_after_slash_emits_literal_chars);
    RUN_TEST(test_htmlParseEndTag_immediate_gt_noop);
    RUN_TEST(test_htmlParseEndTag_bogus_comment_non_letter);
    RUN_TEST(test_htmlParseEndTag_html5_simple_lowercase_name);
    RUN_TEST(test_htmlParseEndTag_html5_with_attrs_and_solidus);
    RUN_TEST(test_htmlParseEndTag_nonhtml5_special_depth_decrement);
    RUN_TEST(test_htmlParseEndTag_nonhtml5_name_not_in_stack_reports_error_and_returns);
    RUN_TEST(test_htmlParseEndTag_nonhtml5_matching_close_emits_end_and_pops);

    int rc = UNITY_END();
    xmlCleanupParser();
    return rc;
}