/*
 * pdfmake_font_write.c - Font PDF object output
 *
 * Writes Font dictionary, FontDescriptor, FontFile2 (embedded TTF),
 * and ToUnicode CMap stream to PDF.
 *
 * Reference: PDF spec §9.6, §9.7, §9.8, §9.9
 * 
 * NOTE: This file provides stub implementations for font writing.
 * Full PDF document integration requires additional doc module support.
 */

#include "pdfmake_font.h"
#include "pdfmake_arena.h"
#include "pdfmake_buf.h"
#include "pdfmake_doc.h"
#include <string.h>
#include <stdlib.h>
#include <stdio.h>

/*============================================================================
 * Main font writer entry point
 * 
 * NOTE: Full implementation requires doc module functions that are not 
 * yet available. Returns a null reference for now.
 *==========================================================================*/

pdfmake_ref_t pdfmake_font_write(pdfmake_font_t *font, pdfmake_doc_t *doc) {
    pdfmake_ref_t null_ref = {0, 0};
    (void)font;
    (void)doc;
    /* TODO: Implement when doc module has object allocation functions */
    return null_ref;
}

/*============================================================================
 * UTF-8 encoding
 *==========================================================================*/

pdfmake_err_t pdfmake_font_encode_utf8(pdfmake_font_t *font,
                                        const char *utf8, size_t len,
                                        pdfmake_buf_t *out_bytes) {
    const uint8_t *p;
    const uint8_t *end;

    if (!font || !utf8 || !out_bytes) return PDFMAKE_EINVAL;

    p = (const uint8_t *)utf8;
    end = p + len;

    while (p < end) {
        uint32_t cp;

        /* Decode UTF-8 */
        if ((*p & 0x80) == 0) {
            cp = *p++;
        } else if ((*p & 0xE0) == 0xC0) {
            if (p + 1 >= end) break;
            cp = (*p++ & 0x1F) << 6;
            cp |= (*p++ & 0x3F);
        } else if ((*p & 0xF0) == 0xE0) {
            if (p + 2 >= end) break;
            cp = (*p++ & 0x0F) << 12;
            cp |= (*p++ & 0x3F) << 6;
            cp |= (*p++ & 0x3F);
        } else if ((*p & 0xF8) == 0xF0) {
            if (p + 3 >= end) break;
            cp = (*p++ & 0x07) << 18;
            cp |= (*p++ & 0x3F) << 12;
            cp |= (*p++ & 0x3F) << 6;
            cp |= (*p++ & 0x3F);
        } else {
            p++;
            continue;
        }
        
        /* Encode based on font type */
        if (font->type == PDFMAKE_FONT_TYPE1) {
            /* WinAnsi encoding */
            uint8_t byte;
            if (cp >= 32 && cp <= 255) {
                byte = (uint8_t)cp;
            } else if (cp == 0x2018) {
                byte = 0x91;
            } else if (cp == 0x2019) {
                byte = 0x92;
            } else if (cp == 0x201C) {
                byte = 0x93;
            } else if (cp == 0x201D) {
                byte = 0x94;
            } else {
                byte = '?';
            }
            pdfmake_buf_append(out_bytes, &byte, 1);
        } else if (font->type == PDFMAKE_FONT_TRUETYPE && font->ttf) {
            /* CID encoding - 2-byte glyph IDs */
            uint16_t gid = pdfmake_ttf_cmap_lookup(font->ttf, cp);
            uint8_t bytes[2];
            pdfmake_ttf_mark_glyph(font->ttf, gid);
            bytes[0] = (gid >> 8) & 0xFF;
            bytes[1] = gid & 0xFF;
            pdfmake_buf_append(out_bytes, bytes, 2);
        }
    }
    
    return PDFMAKE_OK;
}
