#include "../../unity/unity.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <locale.h>
#include <stdint.h>
#include <stdbool.h>
#include <unistd.h>

/* Access to program internals (these are in the same translation unit). */
/* Globals from the program that we adjust in tests. */
extern struct field_range_pair *frp; /* declared in set-fields.h, included in the program */

/* Helper: capture output while calling process_line. */
typedef struct {
    char *out;     /* captured stdout string (malloc'd) */
    int retval;    /* return value from process_line */
    int err;       /* 0 on success, else nonzero */
} CapResult;

static CapResult capture_process_line_call(const char *input, bool newline)
{
    CapResult r = {0};

    /* Create a modifiable copy of input because process_line mutates it. */
    char *mutable_line = NULL;
    size_t inlen = strlen(input);
    mutable_line = (char *)malloc(inlen + 1);
    if (!mutable_line) { r.err = 1; return r; }
    memcpy(mutable_line, input, inlen + 1);

    /* Redirect stdout to a temporary file. */
    FILE *tmp = tmpfile();
    if (!tmp) { free(mutable_line); r.err = 2; return r; }
    fflush(stdout);
    int saved_fd = dup(fileno(stdout));
    if (saved_fd < 0) { fclose(tmp); free(mutable_line); r.err = 3; return r; }
    if (dup2(fileno(tmp), fileno(stdout)) < 0) {
        close(saved_fd); fclose(tmp); free(mutable_line); r.err = 4; return r;
    }

    /* Call the target function while stdout is redirected. */
    int rv = process_line(mutable_line, newline);

    /* Flush and rewind to read captured output. */
    fflush(stdout);
    fflush(tmp);
    fseek(tmp, 0, SEEK_END);
    long sz = ftell(tmp);
    if (sz < 0) sz = 0;
    fseek(tmp, 0, SEEK_SET);
    char *buf = (char *)malloc((size_t)sz + 1);
    if (!buf) {
        /* Restore stdout before returning. */
        dup2(saved_fd, fileno(stdout));
        close(saved_fd);
        fclose(tmp);
        free(mutable_line);
        r.err = 5; return r;
    }
    size_t rd = fread(buf, 1, (size_t)sz, tmp);
    buf[rd] = '\0';

    /* Restore stdout. */
    dup2(saved_fd, fileno(stdout));
    close(saved_fd);
    fclose(tmp);

    r.out = buf;
    r.retval = rv;
    r.err = 0;

    free(mutable_line);
    return r;
}

/* Minimal environment setup helpers (operate on program globals). */
static void set_locale_basics(void)
{
    /* Ensure a simple, predictable locale: C/POSIX */
    setlocale(LC_ALL, "C");

    /* The following identifiers are static globals in the program file.
       Since this test is included in the same translation unit, we can set them. */
    extern const char *decimal_point;
    extern int decimal_point_length;
    extern const char *thousands_sep;
    extern int thousands_sep_length;
    extern unsigned char line_delim;

    /* Force simple decimal and no thousands separator. */
    decimal_point = ".";
    decimal_point_length = 1;
    thousands_sep = "";
    thousands_sep_length = 0;

    line_delim = '\n';
}

static void reset_numfmt_state(void)
{
    /* Reset a subset of globals to defaults that affect processing/printing. */
    extern const char *delimiter;
    extern int auto_padding;
    extern intmax_t padding_width;
    extern int zero_padding_width;
    extern long int user_precision;
    extern const char *suffix;
    extern const char *unit_separator;
    extern int grouping;
    extern enum inval_type inval_style;

    delimiter = NULL;
    auto_padding = 0;
    padding_width = 0;
    zero_padding_width = 0;
    user_precision = -1;
    suffix = NULL;
    unit_separator = NULL;
    grouping = 0;
    inval_style = inval_abort; /* default; tests that need ignore will set it */
}

/* Field range helpers: arrays to control which fields are included. */
static struct field_range_pair FRP_NONE[] = {
    { UINTMAX_MAX, 0 } /* terminator only: include no fields */
};

static struct field_range_pair FRP_ALL[] = {
    { 1, UINTMAX_MAX },
    { UINTMAX_MAX, 0 }
};

static struct field_range_pair FRP_FIRST_ONLY[] = {
    { 1, 1 },
    { UINTMAX_MAX, 0 }
};

void setUp(void) {
    set_locale_basics();
    reset_numfmt_state();
}

void tearDown(void) {
    /* nothing to clean up */
}

/* Test: default whitespace delimiter, no fields included => output identical to input; newline appended. */
void test_process_line_whitespace_preserved_with_newline(void)
{
    extern const char *delimiter;
    delimiter = NULL;  /* whitespace mode */
    frp = FRP_NONE;    /* include no fields => no numeric parsing/conversion */

    const char *in = " 123   456\t789  ";
    CapResult r = capture_process_line_call(in, true);
    TEST_ASSERT_EQUAL_INT_MESSAGE(0, r.err, "capture failed");

    /* Expected: identical input plus a newline. */
    size_t exp_len = strlen(in) + 1;
    char *exp = (char *)malloc(exp_len + 1);
    TEST_ASSERT_NOT_NULL(exp);
    strcpy(exp, in);
    exp[exp_len - 1] = '\n';
    exp[exp_len] = '\0';

    TEST_ASSERT_EQUAL_STRING(exp, r.out);
    TEST_ASSERT_TRUE(r.retval);

    free(exp);
    free(r.out);
}

/* Test: custom simple delimiter, no fields included => output identical; newline appended. */
void test_process_line_custom_delimiter_simple(void)
{
    extern const char *delimiter;
    delimiter = ",";
    frp = FRP_NONE;

    const char *in = "a,b,c";
    CapResult r = capture_process_line_call(in, true);
    TEST_ASSERT_EQUAL_INT_MESSAGE(0, r.err, "capture failed");

    char expected[16];
    snprintf(expected, sizeof expected, "%s\n", in);

    TEST_ASSERT_EQUAL_STRING(expected, r.out);
    TEST_ASSERT_TRUE(r.retval);

    free(r.out);
}

/* Test: multibyte delimiter, no newline requested. */
void test_process_line_multibyte_delimiter_no_newline(void)
{
    extern const char *delimiter;
    delimiter = "\xE2\x98\x83"; /* UTF-8 snowman: ☃ */
    frp = FRP_NONE;

    const char *in = "x\xE2\x98\x83y\xE2\x98\x83z"; /* x☃y☃z */
    CapResult r = capture_process_line_call(in, false);
    TEST_ASSERT_EQUAL_INT_MESSAGE(0, r.err, "capture failed");

    TEST_ASSERT_EQUAL_STRING(in, r.out);
    TEST_ASSERT_TRUE(r.retval);

    free(r.out);
}

/* Test: empty fields with delimiter are preserved exactly. */
void test_process_line_empty_fields_preserved_with_delimiter(void)
{
    extern const char *delimiter;
    delimiter = ",";
    frp = FRP_NONE;

    const char *in = "a,,b,,";
    CapResult r = capture_process_line_call(in, true);
    TEST_ASSERT_EQUAL_INT_MESSAGE(0, r.err, "capture failed");

    char expected[32];
    snprintf(expected, sizeof expected, "%s\n", in);

    TEST_ASSERT_EQUAL_STRING(expected, r.out);
    TEST_ASSERT_TRUE(r.retval);

    free(r.out);
}

/* Test: invalid number in included field returns false, output remains unchanged. */
void test_process_line_invalid_number_included_field_returns_false(void)
{
    /* Include first field only using FRP_FIRST_ONLY (or simply frp=NULL behavior),
       ensure invalid input doesn't abort and returns false. */
    extern enum inval_type inval_style;
    inval_style = inval_ignore; /* avoid exiting on invalid input */

    frp = FRP_FIRST_ONLY;       /* include first field */
    extern const char *delimiter;
    delimiter = NULL;           /* whitespace */

    const char *in = "abc def"; /* 'abc' is not a number */
    CapResult r = capture_process_line_call(in, true);
    TEST_ASSERT_EQUAL_INT_MESSAGE(0, r.err, "capture failed");

    char expected[32];
    snprintf(expected, sizeof expected, "%s\n", in);

    TEST_ASSERT_EQUAL_STRING(expected, r.out);
    TEST_ASSERT_FALSE(r.retval);

    free(r.out);
}

/* Test: include all fields with valid numbers, should return true and print numbers. */
void test_process_line_convert_all_fields_valid(void)
{
    /* With default scale_to=none and no formatting overrides,
       integer numbers should print unchanged. */
    frp = FRP_ALL; /* include all fields */
    extern const char *delimiter;
    delimiter = NULL;

    const char *in = "123 456";
    CapResult r = capture_process_line_call(in, true);
    TEST_ASSERT_EQUAL_INT_MESSAGE(0, r.err, "capture failed");

    char expected[32];
    snprintf(expected, sizeof expected, "%s\n", in);

    TEST_ASSERT_EQUAL_STRING(expected, r.out);
    TEST_ASSERT_TRUE(r.retval);

    free(r.out);
}

int main(void)
{
    UNITY_BEGIN();
    RUN_TEST(test_process_line_whitespace_preserved_with_newline);
    RUN_TEST(test_process_line_custom_delimiter_simple);
    RUN_TEST(test_process_line_multibyte_delimiter_no_newline);
    RUN_TEST(test_process_line_empty_fields_preserved_with_delimiter);
    RUN_TEST(test_process_line_invalid_number_included_field_returns_false);
    RUN_TEST(test_process_line_convert_all_fields_valid);
    return UNITY_END();
}