/*

 * out-limd.c

 * libplist *output-only* format introduced by libimobiledevice/ideviceinfo

 *  - NOT for machine parsing

 *

 * Copyright (c) 2022-2023 Nikias Bassen All Rights Reserved.

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * This library is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with this library; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

 */

#ifdef HAVE_CONFIG_H

#include <config.h>

#endif

#include <string.h>

#include <stdlib.h>

#include <stdio.h>

#include <time.h>

#include <inttypes.h>

#include <ctype.h>

#include <math.h>

#include <limits.h>

#include <node.h>

#include "plist.h"

#include "strbuf.h"

#include "time64.h"

#include "base64.h"

#define MAC_EPOCH 978307200

static size_t dtostr(char *buf, size_t bufsize, double realval)

{

    size_t len = 0;

    if (isnan(realval)) {

        len = snprintf(buf, bufsize, "nan");

    } else if (isinf(realval)) {

        len = snprintf(buf, bufsize, "%cinfinity", (realval > 0.0) ? '+' : '-');

    } else if (realval == 0.0f) {

        len = snprintf(buf, bufsize, "0.0");

    } else {

        size_t i = 0;

        len = snprintf(buf, bufsize, "%.*g", 17, realval);

        for (i = 0; buf && i < len; i++) {

            if (buf[i] == ',') {

                buf[i] = '.';

                break;

            } else if (buf[i] == '.') {

                break;

            }

        }

    }

    return len;

}

static plist_err_t node_to_string(node_t node, bytearray_t **outbuf, uint32_t depth, uint32_t indent)

{

    plist_data_t node_data = NULL;

    char *val = NULL;

    size_t val_len = 0;

    char buf[16];

    uint32_t i = 0;

    if (!node)

        return PLIST_ERR_INVALID_ARG;

    node_data = plist_get_data(node);

    switch (node_data->type)

    {

    case PLIST_BOOLEAN:

    {

        if (node_data->boolval) {

            str_buf_append(*outbuf, "true", 4);

        } else {

            str_buf_append(*outbuf, "false", 5);

        }

    }

    break;

    case PLIST_NULL:

        str_buf_append(*outbuf, "null", 4);

  break;

    case PLIST_INT:

        val = (char*)malloc(64);

        if (node_data->length == 16) {

            val_len = snprintf(val, 64, "%" PRIu64, node_data->intval);

        } else {

            val_len = snprintf(val, 64, "%" PRIi64, node_data->intval);

        }

        str_buf_append(*outbuf, val, val_len);

        free(val);

        break;

    case PLIST_REAL:

        val = (char*)malloc(64);

        val_len = dtostr(val, 64, node_data->realval);

        str_buf_append(*outbuf, val, val_len);

        free(val);

        break;

    case PLIST_STRING:

    case PLIST_KEY: {

        const char *charmap[32] = {

            "\\u0000", "\\u0001", "\\u0002", "\\u0003", "\\u0004", "\\u0005", "\\u0006", "\\u0007",

            "\\b",     "\\t",     "\\n",     "\\u000b", "\\f",     "\\r",     "\\u000e", "\\u000f",

            "\\u0010", "\\u0011", "\\u0012", "\\u0013", "\\u0014", "\\u0015", "\\u0016", "\\u0017",

            "\\u0018", "\\u0019", "\\u001a", "\\u001b", "\\u001c", "\\u001d", "\\u001e", "\\u001f",

        };

        size_t j = 0;

        size_t len = 0;

        off_t start = 0;

        off_t cur = 0;

        len = node_data->length;

        for (j = 0; j < len; j++) {

            unsigned char ch = (unsigned char)node_data->strval[j];

            if (ch < 0x20) {

                str_buf_append(*outbuf, node_data->strval + start, cur - start);

                str_buf_append(*outbuf, charmap[ch], (charmap[ch][1] == 'u') ? 6 : 2);

                start = cur+1;

            }

            cur++;

        }

        str_buf_append(*outbuf, node_data->strval + start, cur - start);

        } break;

    case PLIST_ARRAY: {

        node_t ch;

        uint32_t cnt = 0;

        for (ch = node_first_child(node); ch; ch = node_next_sibling(ch)) {

            if (cnt > 0 || (cnt == 0 && node->parent != NULL)) {

                str_buf_append(*outbuf, "\n", 1);

                for (i = 0; i < depth+indent; i++) {

                    str_buf_append(*outbuf, " ", 1);

                }

            }

            size_t sl = sprintf(buf, "%u: ", cnt);

            str_buf_append(*outbuf, buf, sl);

            plist_err_t res = node_to_string(ch, outbuf, depth+1, indent);

            if (res < 0) {

                return res;

            }

            cnt++;

        }

        } break;

    case PLIST_DICT: {

        node_t ch;

        uint32_t cnt = 0;

        for (ch = node_first_child(node); ch; ch = node_next_sibling(ch)) {

            if (cnt > 0 && cnt % 2 == 0) {

                str_buf_append(*outbuf, "\n", 1);

                for (i = 0; i < depth+indent; i++) {

                    str_buf_append(*outbuf, " ", 1);

                }

            }

            plist_err_t res = node_to_string(ch, outbuf, depth+1, indent);

            if (res < 0) {

                return res;

            }

            if (cnt % 2 == 0) {

                plist_t valnode = (plist_t)node_next_sibling(ch);

                if (PLIST_IS_ARRAY(valnode)) {

                    size_t sl = sprintf(buf, "[%u]:", plist_array_get_size(valnode));

                    str_buf_append(*outbuf, buf, sl);

                } else {

                    str_buf_append(*outbuf, ": ", 2);

                }

            }

            cnt++;

        }

        } break;

    case PLIST_DATA:

        {

            val = (char*)malloc(4096);

            size_t done = 0;

            while (done < node_data->length) {

                size_t amount = node_data->length - done;

                if (amount > 3072) {

                    amount = 3072;

                }

                size_t bsize = base64encode(val, node_data->buff + done, amount);

                str_buf_append(*outbuf, val, bsize);

                done += amount;

            }

        }

        break;

    case PLIST_DATE:

        {

            Time64_T timev = (Time64_T)node_data->realval + MAC_EPOCH;

            struct TM _btime;

            struct TM *btime = gmtime64_r(&timev, &_btime);

            if (btime) {

                val = (char*)calloc(1, 24);

                struct tm _tmcopy;

                copy_TM64_to_tm(btime, &_tmcopy);

                val_len = strftime(val, 24, "%Y-%m-%dT%H:%M:%SZ", &_tmcopy);

                if (val_len > 0) {

                    str_buf_append(*outbuf, val, val_len);

                }

                free(val);

                val = NULL;

            }

        }

        break;

    case PLIST_UID:

        {

            str_buf_append(*outbuf, "CF$UID:", 7);

            val = (char*)malloc(64);

            if (node_data->length == 16) {

                val_len = snprintf(val, 64, "%" PRIu64, node_data->intval);

            } else {

                val_len = snprintf(val, 64, "%" PRIi64, node_data->intval);

            }

            str_buf_append(*outbuf, val, val_len);

            free(val);

        }

        break;

    default:

        return PLIST_ERR_UNKNOWN;

    }

    return PLIST_ERR_SUCCESS;

}

#define PO10i_LIMIT (INT64_MAX/10)

/* based on https://stackoverflow.com/a/4143288 */

static int num_digits_i(int64_t i)

{

    int n;

    int64_t po10;

    n=1;

    if (i < 0) {

        i = (i == INT64_MIN) ? INT64_MAX : -i;

        n++;

    }

    po10=10;

    while (i>=po10) {

        n++;

        if (po10 > PO10i_LIMIT) break;

        po10*=10;

    }

    return n;

}

#define PO10u_LIMIT (UINT64_MAX/10)

/* based on https://stackoverflow.com/a/4143288 */

static int num_digits_u(uint64_t i)

{

    int n;

    uint64_t po10;

    n=1;

    po10=10;

    while (i>=po10) {

        n++;

        if (po10 > PO10u_LIMIT) break;

        po10*=10;

    }

    return n;

}

static plist_err_t node_estimate_size(node_t node, uint64_t *size, uint32_t depth, uint32_t indent)

{

    plist_data_t data;

    if (!node) {

        return PLIST_ERR_INVALID_ARG;

    }

    data = plist_get_data(node);

    if (node->children) {

        node_t ch;

        unsigned int n_children = node_n_children(node);

        for (ch = node_first_child(node); ch; ch = node_next_sibling(ch)) {

            plist_err_t res = node_estimate_size(ch, size, depth + 1, indent);

            if (res < 0) {

                return res;

            }

        }

        switch (data->type) {

        case PLIST_DICT:

            *size += n_children-1; // number of ':' and ' '

            *size += n_children; // number of '\n' and extra space

            *size += (uint64_t)n_children * (depth+indent+1); // indent for every 2nd child

            *size += indent+1; // additional '\n'

            break;

        case PLIST_ARRAY:

            *size += n_children-1; // number of ','

            *size += n_children; // number of '\n'

            *size += (uint64_t)n_children * ((depth+indent+1)<<1); // indent for every child

            *size += indent+1; // additional '\n'

            break;

        default:

            break;

  }

    } else {

        switch (data->type) {

        case PLIST_STRING:

        case PLIST_KEY:

            *size += data->length;

            break;

        case PLIST_INT:

            if (data->length == 16) {

                *size += num_digits_u(data->intval);

            } else {

                *size += num_digits_i((int64_t)data->intval);

            }

            break;

        case PLIST_REAL:

            *size += dtostr(NULL, 0, data->realval);

            break;

        case PLIST_BOOLEAN:

            *size += ((data->boolval) ? 4 : 5);

            break;

        case PLIST_NULL:

            *size += 4;

            break;

        case PLIST_DICT:

        case PLIST_ARRAY:

            *size += 3;

            break;

        case PLIST_DATA:

            *size += (data->length / 3) * 4 + 4;

            break;

        case PLIST_DATE:

            *size += 23;

            break;

        case PLIST_UID:

            *size += 7; // "CF$UID:"

            *size += num_digits_u(data->intval);

            break;

        default:

#ifdef DEBUG

            fprintf(stderr, "%s: invalid node type encountered\n", __func__);

#endif

            return PLIST_ERR_UNKNOWN;

        }

    }

    if (depth == 0) {

        *size += 1; // final newline

    }

    return PLIST_ERR_SUCCESS;

}

static plist_err_t _plist_write_to_strbuf(plist_t plist, strbuf_t *outbuf, plist_write_options_t options)

{

    uint8_t indent = 0;

    if (options & PLIST_OPT_INDENT) {

        indent = (options >> 24) & 0xFF;

    }

    uint8_t i;

    for (i = 0; i < indent; i++) {

        str_buf_append(outbuf, " ", 1);

    }

    plist_err_t res = node_to_string((node_t)plist, &outbuf, 0, indent);

    if (res < 0) {

        return res;

    }

    if (!(options & PLIST_OPT_NO_NEWLINE)) {

        str_buf_append(outbuf, "\n", 1);

    }

    return res;

}

plist_err_t plist_write_to_string_limd(plist_t plist, char **output, uint32_t* length, plist_write_options_t options)

{

    uint64_t size = 0;

    plist_err_t res;

    if (!plist || !output || !length) {

        return PLIST_ERR_INVALID_ARG;

    }

    uint8_t indent = 0;

    if (options & PLIST_OPT_INDENT) {

        indent = (options >> 24) & 0xFF;

    }

    res = node_estimate_size((node_t)plist, &size, 0, indent);

    if (res < 0) {

        return res;

    }

    strbuf_t *outbuf = str_buf_new(size);

    if (!outbuf) {

#if DEBUG

        fprintf(stderr, "%s: Could not allocate output buffer\n", __func__);

#endif

        return PLIST_ERR_NO_MEM;

    }

    res = _plist_write_to_strbuf(plist, outbuf, options);

    if (res < 0) {

        str_buf_free(outbuf);

        *output = NULL;

        *length = 0;

        return res;

    }

    str_buf_append(outbuf, "\0", 1);

    *output = (char*)outbuf->data;

    *length = outbuf->len - 1;

    outbuf->data = NULL;

    str_buf_free(outbuf);

    return PLIST_ERR_SUCCESS;

}

plist_err_t plist_write_to_stream_limd(plist_t plist, FILE *stream, plist_write_options_t options)

{

    if (!plist || !stream) {

        return PLIST_ERR_INVALID_ARG;

    }

    strbuf_t *outbuf = str_buf_new_for_stream(stream);

    if (!outbuf) {

#if DEBUG

        fprintf(stderr, "%s: Could not allocate output buffer\n", __func__);

#endif

        return PLIST_ERR_NO_MEM;

    }

    plist_err_t res = _plist_write_to_strbuf(plist, outbuf, options);

    if (res < 0) {

        str_buf_free(outbuf);

        return res;

    }

    str_buf_free(outbuf);

    return PLIST_ERR_SUCCESS;

}