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

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

/* Wrapper for the static function provided in the module */
extern void test_htmlCheckImplied(htmlParserCtxtPtr ctxt, const xmlChar *newtag);

typedef struct {
    char **names;
    int count;
    int capacity;
} Capture;

static char *xstrdup(const char *s) {
    if (s == NULL) return NULL;
    size_t len = strlen(s) + 1;
    char *d = (char *)malloc(len);
    if (d) memcpy(d, s, len);
    return d;
}

static void cap_init(Capture *cap) {
    cap->names = NULL;
    cap->count = 0;
    cap->capacity = 0;
}

static void cap_add(Capture *cap, const char *name) {
    if (cap->count == cap->capacity) {
        int newcap = (cap->capacity == 0) ? 4 : cap->capacity * 2;
        char **nn = (char **)realloc(cap->names, (size_t)newcap * sizeof(char *));
        if (!nn) return; /* keep silent; tests will fail if memory is out */
        cap->names = nn;
        cap->capacity = newcap;
    }
    cap->names[cap->count++] = xstrdup(name);
}

static void cap_free(Capture *cap) {
    if (cap->names) {
        for (int i = 0; i < cap->count; i++) {
            free(cap->names[i]);
        }
        free(cap->names);
    }
    cap->names = NULL;
    cap->count = 0;
    cap->capacity = 0;
}

static void testStartElement(void *userData, const xmlChar *name, const xmlChar **atts) {
    (void)atts;
    Capture *cap = (Capture *)userData;
    cap_add(cap, (const char *)name);
}

static htmlParserCtxtPtr new_ctxt(Capture *cap, xmlSAXHandlerPtr *out_sax) {
    xmlSAXHandler *sax = (xmlSAXHandler *)calloc(1, sizeof(xmlSAXHandler));
    if (sax == NULL) return NULL;
    memset(sax, 0, sizeof(xmlSAXHandler));
    sax->startElement = testStartElement;

    htmlParserCtxtPtr ctxt = htmlCreatePushParserCtxt(sax, cap, "", 0, NULL, XML_CHAR_ENCODING_NONE);
    if (out_sax) *out_sax = sax;
    return ctxt;
}

static void free_ctxt(htmlParserCtxtPtr ctxt, xmlSAXHandlerPtr sax, Capture *cap) {
    if (ctxt) htmlFreeParserCtxt(ctxt);
    if (sax) free(sax);
    if (cap) cap_free(cap);
}

/* Unity hooks */
void setUp(void) {
    /* No global setup needed */
}

void tearDown(void) {
    /* No global teardown needed */
}

/* Tests */

void test_htmlCheckImplied_with_p_generates_html_and_body(void) {
    Capture cap; cap_init(&cap);
    xmlSAXHandlerPtr sax = NULL;
    htmlParserCtxtPtr ctxt = new_ctxt(&cap, &sax);
    TEST_ASSERT_NOT_NULL(ctxt);

    test_htmlCheckImplied(ctxt, (const xmlChar *)"p");

    TEST_ASSERT_EQUAL_INT(2, cap.count);
    TEST_ASSERT_NOT_NULL(cap.names[0]);
    TEST_ASSERT_NOT_NULL(cap.names[1]);
    TEST_ASSERT_EQUAL_STRING("html", cap.names[0]);
    TEST_ASSERT_EQUAL_STRING("body", cap.names[1]);

    free_ctxt(ctxt, sax, &cap);
}

void test_htmlCheckImplied_with_head_generates_only_html(void) {
    Capture cap; cap_init(&cap);
    xmlSAXHandlerPtr sax = NULL;
    htmlParserCtxtPtr ctxt = new_ctxt(&cap, &sax);
    TEST_ASSERT_NOT_NULL(ctxt);

    test_htmlCheckImplied(ctxt, (const xmlChar *)"head");

    TEST_ASSERT_EQUAL_INT(1, cap.count);
    TEST_ASSERT_EQUAL_STRING("html", cap.names[0]);

    free_ctxt(ctxt, sax, &cap);
}

void test_htmlCheckImplied_with_html_generates_nothing(void) {
    Capture cap; cap_init(&cap);
    xmlSAXHandlerPtr sax = NULL;
    htmlParserCtxtPtr ctxt = new_ctxt(&cap, &sax);
    TEST_ASSERT_NOT_NULL(ctxt);

    test_htmlCheckImplied(ctxt, (const xmlChar *)"html");

    TEST_ASSERT_EQUAL_INT(0, cap.count);

    free_ctxt(ctxt, sax, &cap);
}

void test_htmlCheckImplied_with_script_generates_html_and_head(void) {
    Capture cap; cap_init(&cap);
    xmlSAXHandlerPtr sax = NULL;
    htmlParserCtxtPtr ctxt = new_ctxt(&cap, &sax);
    TEST_ASSERT_NOT_NULL(ctxt);

    test_htmlCheckImplied(ctxt, (const xmlChar *)"script");

    TEST_ASSERT_TRUE(cap.count >= 1);
    TEST_ASSERT_EQUAL_STRING("html", cap.names[0]);
    /* Expect head generation in initial state */
    TEST_ASSERT_EQUAL_INT(2, cap.count);
    TEST_ASSERT_EQUAL_STRING("head", cap.names[1]);

    free_ctxt(ctxt, sax, &cap);
}

void test_htmlCheckImplied_subsequent_p_does_not_generate_body_if_head_present(void) {
    Capture cap; cap_init(&cap);
    xmlSAXHandlerPtr sax = NULL;
    htmlParserCtxtPtr ctxt = new_ctxt(&cap, &sax);
    TEST_ASSERT_NOT_NULL(ctxt);

    /* First call with script: should push html + head */
    test_htmlCheckImplied(ctxt, (const xmlChar *)"script");
    TEST_ASSERT_EQUAL_INT(2, cap.count);
    TEST_ASSERT_EQUAL_STRING("html", cap.names[0]);
    TEST_ASSERT_EQUAL_STRING("head", cap.names[1]);

    /* Second call with p: should not generate body since head is on the stack */
    test_htmlCheckImplied(ctxt, (const xmlChar *)"p");
    TEST_ASSERT_EQUAL_INT(2, cap.count); /* no new events */

    free_ctxt(ctxt, sax, &cap);
}

void test_htmlCheckImplied_no_duplicate_body_on_subsequent_calls(void) {
    Capture cap; cap_init(&cap);
    xmlSAXHandlerPtr sax = NULL;
    htmlParserCtxtPtr ctxt = new_ctxt(&cap, &sax);
    TEST_ASSERT_NOT_NULL(ctxt);

    /* First call with p: expect html + body */
    test_htmlCheckImplied(ctxt, (const xmlChar *)"p");
    TEST_ASSERT_EQUAL_INT(2, cap.count);
    TEST_ASSERT_EQUAL_STRING("html", cap.names[0]);
    TEST_ASSERT_EQUAL_STRING("body", cap.names[1]);

    /* Second call with span: body already on stack, so nothing new */
    test_htmlCheckImplied(ctxt, (const xmlChar *)"span");
    TEST_ASSERT_EQUAL_INT(2, cap.count);

    free_ctxt(ctxt, sax, &cap);
}

void test_htmlCheckImplied_frame_like_tags_do_not_generate_body(void) {
    /* frame */
    {
        Capture cap; cap_init(&cap);
        xmlSAXHandlerPtr sax = NULL;
        htmlParserCtxtPtr ctxt = new_ctxt(&cap, &sax);
        TEST_ASSERT_NOT_NULL(ctxt);

        test_htmlCheckImplied(ctxt, (const xmlChar *)"frame");
        TEST_ASSERT_EQUAL_INT(1, cap.count);
        TEST_ASSERT_EQUAL_STRING("html", cap.names[0]);

        free_ctxt(ctxt, sax, &cap);
    }
    /* frameset */
    {
        Capture cap; cap_init(&cap);
        xmlSAXHandlerPtr sax = NULL;
        htmlParserCtxtPtr ctxt = new_ctxt(&cap, &sax);
        TEST_ASSERT_NOT_NULL(ctxt);

        test_htmlCheckImplied(ctxt, (const xmlChar *)"frameset");
        TEST_ASSERT_EQUAL_INT(1, cap.count);
        TEST_ASSERT_EQUAL_STRING("html", cap.names[0]);

        free_ctxt(ctxt, sax, &cap);
    }
    /* noframes */
    {
        Capture cap; cap_init(&cap);
        xmlSAXHandlerPtr sax = NULL;
        htmlParserCtxtPtr ctxt = new_ctxt(&cap, &sax);
        TEST_ASSERT_NOT_NULL(ctxt);

        test_htmlCheckImplied(ctxt, (const xmlChar *)"noframes");
        TEST_ASSERT_EQUAL_INT(1, cap.count);
        TEST_ASSERT_EQUAL_STRING("html", cap.names[0]);

        free_ctxt(ctxt, sax, &cap);
    }
}

void test_htmlCheckImplied_noimplied_option_suppresses_generation(void) {
    Capture cap; cap_init(&cap);
    xmlSAXHandlerPtr sax = NULL;
    htmlParserCtxtPtr ctxt = new_ctxt(&cap, &sax);
    TEST_ASSERT_NOT_NULL(ctxt);

    /* Set NOIMPLIED option */
    int rc = htmlCtxtUseOptions(ctxt, HTML_PARSE_NOIMPLIED);
    (void)rc;

    test_htmlCheckImplied(ctxt, (const xmlChar *)"p");

    /* No implied insertions should occur */
    TEST_ASSERT_EQUAL_INT(0, cap.count);

    free_ctxt(ctxt, sax, &cap);
}

void test_htmlCheckImplied_html5_option_suppresses_generation(void) {
    Capture cap; cap_init(&cap);
    xmlSAXHandlerPtr sax = NULL;
    htmlParserCtxtPtr ctxt = new_ctxt(&cap, &sax);
    TEST_ASSERT_NOT_NULL(ctxt);

    /* Set HTML5 option */
    int rc = htmlCtxtUseOptions(ctxt, HTML_PARSE_HTML5);
    (void)rc;

    test_htmlCheckImplied(ctxt, (const xmlChar *)"p");

    /* No implied insertions should occur */
    TEST_ASSERT_EQUAL_INT(0, cap.count);

    free_ctxt(ctxt, sax, &cap);
}

int main(void) {
    UNITY_BEGIN();

    RUN_TEST(test_htmlCheckImplied_with_p_generates_html_and_body);
    RUN_TEST(test_htmlCheckImplied_with_head_generates_only_html);
    RUN_TEST(test_htmlCheckImplied_with_html_generates_nothing);
    RUN_TEST(test_htmlCheckImplied_with_script_generates_html_and_head);
    RUN_TEST(test_htmlCheckImplied_subsequent_p_does_not_generate_body_if_head_present);
    RUN_TEST(test_htmlCheckImplied_no_duplicate_body_on_subsequent_calls);
    RUN_TEST(test_htmlCheckImplied_frame_like_tags_do_not_generate_body);
    RUN_TEST(test_htmlCheckImplied_noimplied_option_suppresses_generation);
    RUN_TEST(test_htmlCheckImplied_html5_option_suppresses_generation);

    return UNITY_END();
}