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

/* Wrapper for static function provided in module */
extern void test_htmlParseContent(htmlParserCtxtPtr ctxt);

/* Simple capture structure for SAX events */
typedef struct {
    char *text;
    size_t text_len;

    char *last_comment;
    int comment_count;

    char *internal_subset_name;
    int internal_subset_count;

    char *end_names[32];
    int end_count;
} SaxCapture;

static void cap_init(SaxCapture *cap) {
    memset(cap, 0, sizeof(*cap));
}

static void cap_free(SaxCapture *cap) {
    free(cap->text);
    free(cap->last_comment);
    free(cap->internal_subset_name);
    for (int i = 0; i < cap->end_count; i++)
        free(cap->end_names[i]);
}

static void cap_append_text(SaxCapture *cap, const char *data, size_t len) {
    if (len == 0) return;
    char *newbuf = (char *)realloc(cap->text, cap->text_len + len + 1);
    if (!newbuf) return; /* best effort; tests will fail if NULL */
    cap->text = newbuf;
    memcpy(cap->text + cap->text_len, data, len);
    cap->text_len += len;
    cap->text[cap->text_len] = '\0';
}

/* SAX callbacks */
static void onCharacters(void *userData, const xmlChar *ch, int len) {
    SaxCapture *cap = (SaxCapture *)userData;
    cap_append_text(cap, (const char *)ch, (size_t)len);
}

static void onEndElement(void *userData, const xmlChar *name) {
    SaxCapture *cap = (SaxCapture *)userData;
    if (cap->end_count < (int)(sizeof(cap->end_names)/sizeof(cap->end_names[0]))) {
        const char *src = (const char *)name;
        size_t l = strlen(src);
        cap->end_names[cap->end_count] = (char *)malloc(l + 1);
        if (cap->end_names[cap->end_count]) {
            memcpy(cap->end_names[cap->end_count], src, l + 1);
            cap->end_count++;
        }
    }
}

static void onComment(void *userData, const xmlChar *value) {
    SaxCapture *cap = (SaxCapture *)userData;
    free(cap->last_comment);
    cap->last_comment = strdup((const char *)value);
    cap->comment_count++;
}

static void onInternalSubset(void *userData, const xmlChar *name, const xmlChar *ExternalID, const xmlChar *SystemID) {
    (void)ExternalID; (void)SystemID;
    SaxCapture *cap = (SaxCapture *)userData;
    free(cap->internal_subset_name);
    cap->internal_subset_name = strdup((const char *)name);
    cap->internal_subset_count++;
}

/* Shared SAX handler */
static htmlSAXHandler make_sax(void) {
    htmlSAXHandler sax;
    memset(&sax, 0, sizeof(sax));
    sax.characters = onCharacters;
    sax.endElement = onEndElement;
    sax.comment = onComment;
    sax.internalSubset = onInternalSubset;
    return sax;
}

/* Helper to create a parser context with our SAX */
static htmlParserCtxtPtr make_ctxt_with_sax(const char *data, SaxCapture *cap) {
    htmlParserCtxtPtr ctxt = htmlCreateMemoryParserCtxt(data, (int)strlen(data));
    if (ctxt) {
        static htmlSAXHandler sax; /* initialized per call */
        sax = make_sax();
        ctxt->sax = &sax;
        ctxt->userData = cap;
        ctxt->disableSAX = 0;
    }
    return ctxt;
}

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

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

/* Tests */
void test_htmlParseContent_plain_text(void) {
    const char *html = "Hello";
    SaxCapture cap; cap_init(&cap);

    htmlParserCtxtPtr ctxt = make_ctxt_with_sax(html, &cap);
    TEST_ASSERT_NOT_NULL(ctxt);

    test_htmlParseContent(ctxt);

    TEST_ASSERT_NOT_NULL(cap.text);
    TEST_ASSERT_EQUAL_STRING("Hello", cap.text);
    TEST_ASSERT_EQUAL_INT(0, cap.comment_count);

    htmlFreeParserCtxt(ctxt);
    cap_free(&cap);
}

void test_htmlParseContent_element_with_end_tag(void) {
    const char *html = "<p>Hi</p>";
    SaxCapture cap; cap_init(&cap);

    htmlParserCtxtPtr ctxt = make_ctxt_with_sax(html, &cap);
    TEST_ASSERT_NOT_NULL(ctxt);

    test_htmlParseContent(ctxt);

    TEST_ASSERT_NOT_NULL(cap.text);
    TEST_ASSERT_EQUAL_STRING("Hi", cap.text);
    TEST_ASSERT_TRUE(cap.end_count >= 1);
    /* The first explicit end should be </p> */
    TEST_ASSERT_EQUAL_STRING("p", cap.end_names[0]);

    htmlFreeParserCtxt(ctxt);
    cap_free(&cap);
}

void test_htmlParseContent_comment_and_bogus_comment(void) {
    const char *html1 = "X<!--abc-->Y";
    SaxCapture cap1; cap_init(&cap1);
    htmlParserCtxtPtr ctxt1 = make_ctxt_with_sax(html1, &cap1);
    TEST_ASSERT_NOT_NULL(ctxt1);
    test_htmlParseContent(ctxt1);
    TEST_ASSERT_EQUAL_INT(1, cap1.comment_count);
    TEST_ASSERT_EQUAL_STRING("abc", cap1.last_comment);
    TEST_ASSERT_EQUAL_STRING("XY", cap1.text);
    htmlFreeParserCtxt(ctxt1);
    cap_free(&cap1);

    const char *html2 = "A<!zzz>B"; /* bogus comment starting after <! */
    SaxCapture cap2; cap_init(&cap2);
    htmlParserCtxtPtr ctxt2 = make_ctxt_with_sax(html2, &cap2);
    TEST_ASSERT_NOT_NULL(ctxt2);
    test_htmlParseContent(ctxt2);
    TEST_ASSERT_EQUAL_INT(1, cap2.comment_count);
    TEST_ASSERT_EQUAL_STRING("zzz", cap2.last_comment);
    TEST_ASSERT_EQUAL_STRING("AB", cap2.text);
    htmlFreeParserCtxt(ctxt2);
    cap_free(&cap2);
}

void test_htmlParseContent_literal_lt_when_not_a_tag(void) {
    const char *html = "<1";
    SaxCapture cap; cap_init(&cap);
    htmlParserCtxtPtr ctxt = make_ctxt_with_sax(html, &cap);
    TEST_ASSERT_NOT_NULL(ctxt);

    test_htmlParseContent(ctxt);

    TEST_ASSERT_NOT_NULL(cap.text);
    TEST_ASSERT_EQUAL_STRING("<1", cap.text);

    htmlFreeParserCtxt(ctxt);
    cap_free(&cap);
}

void test_htmlParseContent_doctype_in_content(void) {
    const char *html = "<!DOCTYPE html>Text";
    SaxCapture cap; cap_init(&cap);
    htmlParserCtxtPtr ctxt = make_ctxt_with_sax(html, &cap);
    TEST_ASSERT_NOT_NULL(ctxt);

    test_htmlParseContent(ctxt);

    TEST_ASSERT_EQUAL_INT(1, cap.internal_subset_count);
    TEST_ASSERT_NOT_NULL(cap.internal_subset_name);
    TEST_ASSERT_EQUAL_STRING("html", cap.internal_subset_name);
    TEST_ASSERT_EQUAL_STRING("Text", cap.text);

    htmlFreeParserCtxt(ctxt);
    cap_free(&cap);
}

void test_htmlParseContent_autoclose_on_end(void) {
    const char *html = "<p>ab"; /* no closing tag */
    SaxCapture cap; cap_init(&cap);
    htmlParserCtxtPtr ctxt = make_ctxt_with_sax(html, &cap);
    TEST_ASSERT_NOT_NULL(ctxt);

    test_htmlParseContent(ctxt);

    TEST_ASSERT_EQUAL_STRING("ab", cap.text);
    /* At end-of-input, auto-close should at least close <p> */
    TEST_ASSERT_TRUE(cap.end_count >= 1);
    TEST_ASSERT_EQUAL_STRING("p", cap.end_names[0]);

    htmlFreeParserCtxt(ctxt);
    cap_free(&cap);
}

void test_htmlParseContent_script_mode_preserves_lt_inside_script(void) {
    const char *html = "<script>1<2</script>";
    SaxCapture cap; cap_init(&cap);
    htmlParserCtxtPtr ctxt = make_ctxt_with_sax(html, &cap);
    TEST_ASSERT_NOT_NULL(ctxt);

    test_htmlParseContent(ctxt);

    TEST_ASSERT_NOT_NULL(cap.text);
    TEST_ASSERT_EQUAL_STRING("1<2", cap.text);
    /* Ensure script element was closed */
    TEST_ASSERT_TRUE(cap.end_count >= 1);
    /* one of the closed elements should be script; it might not be the first if nested wrappers close after */
    int saw_script = 0;
    for (int i = 0; i < cap.end_count; i++) {
        if (strcmp(cap.end_names[i], "script") == 0) {
            saw_script = 1; break;
        }
    }
    TEST_ASSERT_TRUE(saw_script);

    htmlFreeParserCtxt(ctxt);
    cap_free(&cap);
}

int main(void) {
    UNITY_BEGIN();
    RUN_TEST(test_htmlParseContent_plain_text);
    RUN_TEST(test_htmlParseContent_element_with_end_tag);
    RUN_TEST(test_htmlParseContent_comment_and_bogus_comment);
    RUN_TEST(test_htmlParseContent_literal_lt_when_not_a_tag);
    RUN_TEST(test_htmlParseContent_doctype_in_content);
    RUN_TEST(test_htmlParseContent_autoclose_on_end);
    RUN_TEST(test_htmlParseContent_script_mode_preserves_lt_inside_script);
    return UNITY_END();
}