#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);
    }
}

static void format_message(char* buffer, size_t size, const char* msg, va_list args) {
    // Basic implementation that handles %S for String and passes others to vsnprintf
    // This is a simplified version. For a real compiler, we'd want a more robust one.
    
    char fmt_temp[1024];
    char* fmt_ptr = fmt_temp;
    const char* m = msg;
    
    // We can't easily mix va_list with custom handling without specialized logic.
    // For now, let's just use vsnprintf and assume %S is not used yet, 
    // OR we can try to handle %S if we really need it.
    // Given the complexity, let's just fix the Location/String field access first.
    
    vsnprintf(buffer, size, msg, args);
}

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_start + 1;
    if (caret_len < 1) caret_len = 1;

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

    size_t total_size = strlen(loc->filename) + 16 + // --- filename ---
                        prefix_len + loc->line_text.length + 2 + // line| text\n
                        prefix_len + loc->column_start - 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, (int)loc->line_text.length, loc->line_text.data);
    
    // Caret line
    for (int i = 0; i < prefix_len + loc->column_start - 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);
}