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

/* Wrapper for the static function under test (provided in the module). */
extern void test_htmlParseTryOrFinish(htmlParserCtxtPtr ctxt, int terminate);

/* Helpers */
static htmlParserCtxtPtr make_ctx_from_mem(const char *buf, int len) {
    htmlParserCtxtPtr ctxt = htmlCreateMemoryParserCtxt(buf, len);
    TEST_ASSERT_NOT_NULL_MESSAGE(ctxt, "Failed to create HTML parser context");
    /* Be permissive to avoid errors affecting the test */
    (void)htmlCtxtUseOptions(ctxt, HTML_PARSE_RECOVER | HTML_PARSE_NOERROR | HTML_PARSE_NOWARNING);
    return ctxt;
}

static size_t cur_offset(htmlParserCtxtPtr ctxt) {
    return (size_t)(ctxt->input->cur - ctxt->input->base);
}

static size_t end_offset(htmlParserCtxtPtr ctxt) {
    return (size_t)(ctxt->input->end - ctxt->input->base);
}

/* Unity hooks */
void setUp(void) {
    /* Initialize library per test to be safe */
    xmlInitParser();
}

void tearDown(void) {
    /* No global cleanup here; contexts are freed in tests */
}

/* Tests */

void test_htmlParseTryOrFinish_start_nonterminate_small_avail_returns_early(void) {
    const char *data = "abc"; /* less than 4 bytes */
    htmlParserCtxtPtr ctxt = make_ctx_from_mem(data, (int)strlen(data));
    TEST_ASSERT_EQUAL_INT(XML_PARSER_START, ctxt->instate);

    size_t before_cur = cur_offset(ctxt);
    test_htmlParseTryOrFinish(ctxt, 0);

    /* Should not have progressed from START due to insufficient bytes and non-terminate */
    TEST_ASSERT_EQUAL_INT(XML_PARSER_START, ctxt->instate);
    TEST_ASSERT_EQUAL_size_t(before_cur, cur_offset(ctxt));

    htmlFreeParserCtxt(ctxt);
}

void test_htmlParseTryOrFinish_start_terminate_progresses_and_consumes_text(void) {
    const char *data = "abc";
    htmlParserCtxtPtr ctxt = make_ctx_from_mem(data, (int)strlen(data));
    size_t end = end_offset(ctxt);

    test_htmlParseTryOrFinish(ctxt, 1);

    /* Should have progressed into CONTENT and consumed the text */
    TEST_ASSERT_EQUAL_INT(XML_PARSER_CONTENT, ctxt->instate);
    TEST_ASSERT_EQUAL_size_t(end, cur_offset(ctxt));
    /* endCheckState should be 0 after plain text consumption */
    TEST_ASSERT_EQUAL_INT(0, ctxt->endCheckState);

    htmlFreeParserCtxt(ctxt);
}

void test_htmlParseTryOrFinish_misc_to_start_tag_partial_nonterminate(void) {
    /* 4 spaces ensure we pass START; "<p" triggers START_TAG with missing '>' */
    const char *data = "    <p";
    htmlParserCtxtPtr ctxt = make_ctx_from_mem(data, (int)strlen(data));

    test_htmlParseTryOrFinish(ctxt, 0);

    /* With terminate == 0 and no '>', the function should return in START_TAG state */
    TEST_ASSERT_EQUAL_INT(XML_PARSER_START_TAG, ctxt->instate);
    /* htmlParseLookupGt should have set a non-zero checkIndex for rescanning */
    TEST_ASSERT_TRUE(ctxt->checkIndex != 0);

    /* Input cursor should not have consumed the '<p' (still at or before '<') */
    /* We expect no advance past the '<' since we bailed out before parsing tag */
    /* It's acceptable if whitespace was skipped while moving into MISC. Ensure not at end. */
    TEST_ASSERT_TRUE(cur_offset(ctxt) < end_offset(ctxt));

    htmlFreeParserCtxt(ctxt);
}

void test_htmlParseTryOrFinish_parses_comment_and_advances(void) {
    const char *data = "<!--x-->";
    htmlParserCtxtPtr ctxt = make_ctx_from_mem(data, (int)strlen(data));
    size_t end = end_offset(ctxt);

    test_htmlParseTryOrFinish(ctxt, 1);

    /* Cursor should be at end after consuming the comment */
    TEST_ASSERT_EQUAL_size_t(end, cur_offset(ctxt));
    /* State likely remains in MISC or CONTENT; just ensure not EOF */
    TEST_ASSERT_NOT_EQUAL_INT(XML_PARSER_EOF, ctxt->instate);

    htmlFreeParserCtxt(ctxt);
}

void test_htmlParseTryOrFinish_parses_simple_element_and_end_tag_full_terminate(void) {
    const char *data = "<p>Hi</p>";
    htmlParserCtxtPtr ctxt = make_ctx_from_mem(data, (int)strlen(data));
    size_t end = end_offset(ctxt);

    test_htmlParseTryOrFinish(ctxt, 1);

    /* Should have consumed the entire input */
    TEST_ASSERT_EQUAL_size_t(end, cur_offset(ctxt));
    /* Should be in CONTENT after handling tags and text */
    TEST_ASSERT_EQUAL_INT(XML_PARSER_CONTENT, ctxt->instate);
    TEST_ASSERT_EQUAL_INT(0, ctxt->endCheckState);

    htmlFreeParserCtxt(ctxt);
}

void test_htmlParseTryOrFinish_end_tag_only_transitions_and_consumes(void) {
    const char *data = "</p>";
    htmlParserCtxtPtr ctxt = make_ctx_from_mem(data, (int)strlen(data));
    size_t end = end_offset(ctxt);

    test_htmlParseTryOrFinish(ctxt, 1);

    /* End tag should be consumed fully */
    TEST_ASSERT_EQUAL_size_t(end, cur_offset(ctxt));
    /* After processing end tag, parser returns to CONTENT */
    TEST_ASSERT_EQUAL_INT(XML_PARSER_CONTENT, ctxt->instate);

    htmlFreeParserCtxt(ctxt);
}

/* Main */
int main(void) {
    UNITY_BEGIN();
    RUN_TEST(test_htmlParseTryOrFinish_start_nonterminate_small_avail_returns_early);
    RUN_TEST(test_htmlParseTryOrFinish_start_terminate_progresses_and_consumes_text);
    RUN_TEST(test_htmlParseTryOrFinish_misc_to_start_tag_partial_nonterminate);
    RUN_TEST(test_htmlParseTryOrFinish_parses_comment_and_advances);
    RUN_TEST(test_htmlParseTryOrFinish_parses_simple_element_and_end_tag_full_terminate);
    RUN_TEST(test_htmlParseTryOrFinish_end_tag_only_transitions_and_consumes);
    return UNITY_END();
}