#define _POSIX_C_SOURCE 1
#include <dirent.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <unistd.h>

#include "../src/Colors.h"

static bool endsWith(const char* s, const char* end) {
    size_t a = strlen(s);
    size_t b = strlen(end);
    if(a < b) {
        return false;
    }
    return strcmp(s + (a - b), end) == 0;
}

static void printTests() {
    const char* path = "./test";
    DIR* d = opendir(path);
    if(d == nullptr) {
        return;
    }
    while(true) {
        struct dirent* file = readdir(d);
        if(file == nullptr) {
            break;
        }
        if(endsWith(file->d_name, ".basic")) {
            printf("%s/%s\n", path, file->d_name);
        }
    }
    closedir(d);
}

static void printUntilNewline(const char* s) {
    while(*s != '\n' && *s != '\0') {
        putchar(*(s++));
    }
}

static void compareStreams(FILE* file, FILE* result) {
    bool diff = false;
    int line = 0;
    while(true) {
        line++;
        char bufferA[256] = {};
        char bufferB[256] = {};
        char* r1 = fgets(bufferA, sizeof(bufferA), file);
        char* r2 = fgets(bufferB, sizeof(bufferB), result);
        if(r1 == nullptr && r2 == nullptr) {
            break;
        }
        if(strcmp(bufferA, bufferB) != 0) {
            printf(TC_RED "Line %d differs '", line);
            printUntilNewline(bufferA);
            printf("' vs '");
            printUntilNewline(bufferB);
            puts("'" TC_RESET);
            diff = true;
        }
    }
    if(!diff) {
        puts(TC_GREEN "Success" TC_RESET);
    }
}

int main(int argCount, const char** args) {
    if(argCount < 2) {
        return 0;
    } else if(strcmp(args[1], "help") == 0) {
        printTests();
        return 0;
    }
    int fd[2];
    if(pipe(fd) == -1) {
        puts("pipe failed");
        return 1;
    }
    pid_t f = fork();
    if(f == 0) { // child
        close(fd[0]);
        dup2(fd[1], STDOUT_FILENO);
        close(fd[1]);
#ifdef NDEBUG
        const char* path = "./build_release/basic";
#else
        const char* path = "./build_debug/basic";
#endif
        execlp(path, path, args[1], (char*)nullptr);
        puts("execlp failed");
        exit(1);
    } else if(f == -1) { // failure
        puts("fork failed");
        exit(1);
    }
    close(fd[1]);

    char resultPath[256];
    snprintf(resultPath, sizeof(resultPath), "%s_result", args[1]);
    FILE* file = fopen(resultPath, "r");
    if(file == nullptr) {
        printf(TC_RED "'%s' does not exist" TC_RESET "\n", resultPath);
        return 1;
    }
    FILE* result = fdopen(fd[0], "r");
    if(result == nullptr) {
        puts("Cannot map file descriptor");
    } else {
        compareStreams(file, result);
        fclose(result);
    }
    fclose(file);
    return 1;
}