#include "log.h"
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <stdarg.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(Location* loc, int to_column, const char* msg, ...) {
    char line_prefix[32];
    int prefix_len = snprintf(line_prefix, sizeof(line_prefix), "%d| ", loc->line);
    
    int caret_len = to_column - loc->column + 1;
    if (caret_len < 1) caret_len = 1;

    // Format the message
    va_list args;
    va_start(args, msg);
    char formatted_msg[256];
    vsnprintf(formatted_msg, sizeof(formatted_msg), msg, args);
    va_end(args);

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

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

    char* p = buffer;
    p += sprintf(p, "--- %s ---\n", loc->filename);
    p += sprintf(p, "%s%s\n", line_prefix, loc->line_text);
    
    // Caret line
    for (int i = 0; i < prefix_len + loc->column - 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", formatted_msg);
    
    *p = '\0';

    log_error(buffer);
    free(buffer);
}