#include "../../unity/unity.h"
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <stdbool.h>

/* Helper: make a stream positioned so that getc(f) returns the byte
   immediately after the supplied initial 'c'. I.e., write only the
   remaining bytes after 'c' into the stream. */
static FILE* make_stream_from(const char* remainder)
{
    FILE* f = tmpfile();
    TEST_ASSERT_NOT_NULL(f);
    if (remainder && *remainder)
    {
        size_t n = fwrite(remainder, 1, strlen(remainder), f);
        TEST_ASSERT_EQUAL_UINT(strlen(remainder), n);
    }
    rewind(f);
    return f;
}

/* Helper: copy word text into a NUL-terminated string for comparison. */
static char* copy_word_text(WORD *w)
{
    char *s = (char*)malloc((size_t)w->length + 1);
    TEST_ASSERT_NOT_NULL(s);
    memcpy(s, w->text, (size_t)w->length);
    s[w->length] = '\0';
    return s;
}

/* Reset global parsing state to a clean baseline before each test. */
void setUp(void)
{
    /* Ensure we start filling the paragraph buffers from scratch. */
    wptr = parabuf;
    word_limit = word;

    /* Reset general flags/state affecting get_line and get_prefix. */
    tabs = false;
    uniform = false;

    /* No prefix in effect. */
    prefix = "";
    prefix_full_length = 0;
    prefix_length = 0;
    prefix_lead_space = 0;

    /* Initial column before the first non-blank char of the test line. */
    in_column = 0;
}

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

/* Basic tokenization: two words, single spaces, newline ending; checks return of next line's first char and indentation. */
static void test_get_line_basic_two_words(void)
{
    /* Simulate input line: "Hello world\n  Next" with c = 'H' and stream containing "ello world\n  Next" */
    FILE *f = make_stream_from("ello world\n  Next");
    int c = 'H';

    int ret = get_line(f, c);

    /* After parsing, there should be 2 words: "Hello" and "world" */
    TEST_ASSERT_EQUAL_INT(2, (int)(word_limit - word));

    {
        WORD *w0 = &word[0];
        char *s0 = copy_word_text(w0);
        TEST_ASSERT_EQUAL_STRING("Hello", s0);
        TEST_ASSERT_EQUAL_INT(5, w0->length);
        TEST_ASSERT_FALSE(w0->period);
        TEST_ASSERT_FALSE(w0->punct);
        TEST_ASSERT_FALSE(w0->final);
        TEST_ASSERT_FALSE(w0->paren);
        TEST_ASSERT_EQUAL_INT(1, w0->space);
        free(s0);
    }
    {
        WORD *w1 = &word[1];
        char *s1 = copy_word_text(w1);
        TEST_ASSERT_EQUAL_STRING("world", s1);
        TEST_ASSERT_EQUAL_INT(5, w1->length);
        TEST_ASSERT_FALSE(w1->period);
        TEST_ASSERT_FALSE(w1->punct);
        TEST_ASSERT_FALSE(w1->final);
        TEST_ASSERT_FALSE(w1->paren);
        /* End of line causes space to be normalized to 1 */
        TEST_ASSERT_EQUAL_INT(1, w1->space);
        free(s1);
    }

    /* Next line starts with two spaces then 'N'; get_line returns 'N' and sets in_column to 2 */
    TEST_ASSERT_EQUAL_INT('N', ret);
    TEST_ASSERT_EQUAL_INT(2, in_column);

    fclose(f);
}

/* Sentence end detection with trailing closing punctuation and two spaces after, ensuring final and space=2. */
static void test_get_line_sentence_end_with_closer(void)
{
    /* Simulate: "Hello.)  Next\nX" */
    FILE *f = make_stream_from("ello.)  Next\nX");
    int c = 'H';

    int ret = get_line(f, c);

    TEST_ASSERT_EQUAL_INT(2, (int)(word_limit - word));

    {
        WORD *w0 = &word[0];
        char *s0 = copy_word_text(w0);
        TEST_ASSERT_EQUAL_STRING("Hello.)", s0);
        TEST_ASSERT_EQUAL_INT(7, w0->length);
        /* ')' is punctuation, period should be detected at '.' after trimming ')' */
        TEST_ASSERT_TRUE(w0->punct);
        TEST_ASSERT_TRUE(w0->period);
        /* Two spaces after a sentence-ending word -> final true, space remains 2 (uniform=false) */
        TEST_ASSERT_TRUE(w0->final);
        TEST_ASSERT_EQUAL_INT(2, w0->space);
        TEST_ASSERT_FALSE(w0->paren);
        free(s0);
    }
    {
        WORD *w1 = &word[1];
        char *s1 = copy_word_text(w1);
        TEST_ASSERT_EQUAL_STRING("Next", s1);
        TEST_ASSERT_EQUAL_INT(4, w1->length);
        TEST_ASSERT_FALSE(w1->period);
        TEST_ASSERT_FALSE(w1->final);
        TEST_ASSERT_EQUAL_INT(1, w1->space); /* newline normalization */
        free(s1);
    }

    /* Next line (after newline) starts with 'X' */
    TEST_ASSERT_EQUAL_INT('X', ret);
    TEST_ASSERT_EQUAL_INT(0, in_column);

    fclose(f);
}

/* Tabs expansion: measures inter-word spacing to next tab stop and sets tabs=true. */
static void test_get_line_tab_expansion_and_tabs_flag(void)
{
    /* Simulate: "abc\tdef\nZ" */
    FILE *f = make_stream_from("bc\tdef\nZ");
    int c = 'a';

    int ret = get_line(f, c);

    TEST_ASSERT_EQUAL_INT(2, (int)(word_limit - word));

    {
        WORD *w0 = &word[0];
        char *s0 = copy_word_text(w0);
        TEST_ASSERT_EQUAL_STRING("abc", s0);
        TEST_ASSERT_EQUAL_INT(3, w0->length);
        /* At col 3, next tab stop is at 8 -> space measured is 5 */
        TEST_ASSERT_EQUAL_INT(5, w0->space);
        TEST_ASSERT_TRUE(tabs);
        free(s0);
    }
    {
        WORD *w1 = &word[1];
        char *s1 = copy_word_text(w1);
        TEST_ASSERT_EQUAL_STRING("def", s1);
        TEST_ASSERT_EQUAL_INT(3, w1->length);
        TEST_ASSERT_EQUAL_INT(1, w1->space); /* newline normalization */
        free(s1);
    }

    TEST_ASSERT_EQUAL_INT('Z', ret);
    TEST_ASSERT_EQUAL_INT(0, in_column);

    fclose(f);
}

/* Uniform spacing: multiple spaces between non-final words should be normalized to 1 when uniform=true. */
static void test_get_line_uniform_spacing_normalizes_interword_space(void)
{
    /* Common input: "a   b\nX" */
    const char *remainder = "   b\nX";
    int c = 'a';

    /* First with uniform=false: keep measured spaces (3) */
    {
        FILE *f = make_stream_from(remainder);
        uniform = false;
        wptr = parabuf;
        word_limit = word;
        in_column = 0;

        int ret = get_line(f, c);
        TEST_ASSERT_EQUAL_INT(2, (int)(word_limit - word));
        TEST_ASSERT_EQUAL_INT(3, word[0].space);
        TEST_ASSERT_EQUAL_INT('X', ret);
        fclose(f);
    }

    /* Then with uniform=true: normalize to 1 space since not sentence-final */
    {
        FILE *f = make_stream_from(remainder);
        uniform = true;
        wptr = parabuf;
        word_limit = word;
        in_column = 0;

        int ret = get_line(f, c);
        TEST_ASSERT_EQUAL_INT(2, (int)(word_limit - word));
        TEST_ASSERT_EQUAL_INT(1, word[0].space);
        TEST_ASSERT_EQUAL_INT('X', ret);
        fclose(f);
    }
}

/* Parenthesis detection: word starting with '(' sets paren=true; trailing ')' is punctuation but not a period. */
static void test_get_line_paren_and_punct_flags(void)
{
    /* Simulate: "(test) ok\nY" */
    FILE *f = make_stream_from("test) ok\nY");
    int c = '(';

    int ret = get_line(f, c);

    TEST_ASSERT_EQUAL_INT(2, (int)(word_limit - word));

    {
        WORD *w0 = &word[0];
        char *s0 = copy_word_text(w0);
        TEST_ASSERT_EQUAL_STRING("(test)", s0);
        TEST_ASSERT_TRUE(w0->paren);
        TEST_ASSERT_TRUE(w0->punct);  /* ends with ')' */
        TEST_ASSERT_FALSE(w0->period);/* '(' trimmed only affects period detection; here last non-closer is 't' */
        TEST_ASSERT_FALSE(w0->final);
        TEST_ASSERT_EQUAL_INT(1, w0->space);
        free(s0);
    }
    {
        WORD *w1 = &word[1];
        char *s1 = copy_word_text(w1);
        TEST_ASSERT_EQUAL_STRING("ok", s1);
        TEST_ASSERT_FALSE(w1->paren);
        TEST_ASSERT_FALSE(w1->period);
        TEST_ASSERT_FALSE(w1->final);
        TEST_ASSERT_EQUAL_INT(1, w1->space);
        free(s1);
    }

    TEST_ASSERT_EQUAL_INT('Y', ret);
    TEST_ASSERT_EQUAL_INT(0, in_column);

    fclose(f);
}

/* EOF termination: line without trailing newline should set final=true and return EOF. */
static void test_get_line_eof_terminated_line(void)
{
    /* Simulate "last" with EOF: pass c='l', stream contains "ast" */
    FILE *f = make_stream_from("ast");
    int c = 'l';

    int ret = get_line(f, c);

    TEST_ASSERT_EQUAL_INT(1, (int)(word_limit - word));

    {
        WORD *w0 = &word[0];
        char *s0 = copy_word_text(w0);
        TEST_ASSERT_EQUAL_STRING("last", s0);
        TEST_ASSERT_TRUE(w0->final); /* EOF makes final true */
        TEST_ASSERT_EQUAL_INT(2, w0->space); /* normalized at EOF */
        free(s0);
    }

    TEST_ASSERT_EQUAL_INT(EOF, ret);
    /* in_column gets reset to 0 in get_prefix when encountering EOF */
    TEST_ASSERT_EQUAL_INT(0, in_column);

    fclose(f);
}

int main(void)
{
    UNITY_BEGIN();
    RUN_TEST(test_get_line_basic_two_words);
    RUN_TEST(test_get_line_sentence_end_with_closer);
    RUN_TEST(test_get_line_tab_expansion_and_tabs_flag);
    RUN_TEST(test_get_line_uniform_spacing_normalizes_interword_space);
    RUN_TEST(test_get_line_paren_and_punct_flags);
    RUN_TEST(test_get_line_eof_terminated_line);
    return UNITY_END();
}