#include "log.h"
#include <stdio.h>
#include <string.h>
#include <stdlib.h>

static LogError* s_logError = NULL;

void log_set_output(LogError* destination) {
    s_logError = destination;
}

void log_error(const char* msg) {
    if (s_logError != NULL) {
        s_logError(msg);
    } else {
        fprintf(stderr, "Error: %s\n", msg);
    }
}

void log_on_line(const char* filename, const char* line_text, int line, int from, int to, const char* msg) {
    char line_prefix[32];
    int prefix_len = snprintf(line_prefix, sizeof(line_prefix), "%d| ", line);
    
    int caret_len = to - from + 1;
    if (caret_len < 1) caret_len = 1;

    size_t total_size = strlen(filename) + 16 + // --- filename ---
                        prefix_len + strlen(line_text) + 2 + // line| text\n
                        prefix_len + from - 1 + caret_len + 2 + // indent + ^^\n
                        prefix_len + strlen(msg) + 2 + // indent + msg\n
                        1;

    char* buffer = (char*)malloc(total_size);
    if (!buffer) return;

    char* p = buffer;
    p += sprintf(p, "--- %s ---\n", filename);
    p += sprintf(p, "%s%s\n", line_prefix, line_text);
    
    // Caret line
    for (int i = 0; i < prefix_len + from - 1; i++) *p++ = ' ';
    for (int i = 0; i < caret_len; i++) *p++ = '^';
    *p++ = '\n';

    // Message line
    for (int i = 0; i < prefix_len; i++) *p++ = ' ';
    p += sprintf(p, "%s\n", msg);
    
    *p = '\0';

    log_error(buffer);
    free(buffer);
}