#include "c_StrIndexKmp.h"
#include <stdlib.h>
#include <stdio.h>

void test_log(const char* test_name) {
    printf("[PASS] %s\n", test_name);
}

int main() {
    printf("==================================================\n");
    printf(" Starting KMP String Search Algorithm Unit Tests\n");
    printf("==================================================\n\n");

    // Test 1: Standard match discovery
    const char* text1 = "ABABDABACDABABCABAB";
    long long idx1 = c_StrIndexKmp(text1, "ABABCABAB");
    assert(idx1 == 10);
    test_log("1. Pattern found at index 10 successfully");

    // Test 2: Repeating partial pattern fallback (Corrected text and pattern)
    // At index 0, text matches "ABABA" but mismatches on the 6th char ('B' vs 'C').
    // The LPS table causes j to backtrack smoothly, discovering the real match starting at index 2.
    const char* text2 = "ABABABACATA";
    long long idx2 = c_StrIndexKmp(text2, "ABABAC");
    assert(idx2 == 2);
    test_log("2. Partial-match backtracking table lookup verified at index 2");

    // Test 3: Pattern not present in text
    long long idx3 = c_StrIndexKmp(text1, "XYZ");
    assert(idx3 == -1);
    test_log("3. Non-existent substring pattern returns -1 safely");

    // Test 4: Empty pattern handling boundary check
    long long idx4 = c_StrIndexKmp(text1, "");
    assert(idx4 == 0);
    test_log("4. Empty string matches target index 0");

    // Test 5: Pattern longer than string payload boundary check
    long long idx5 = c_StrIndexKmp("short", "extremely_long_pattern");
    assert(idx5 == -1);
    test_log("5. Length mismatch constraints handled gracefully");

    printf("\n==================================================\n");
    printf(" Success! All KMP test assertions passed successfully!\n");
    printf("==================================================\n");
    return 0;
}