/*
 * Parse the legacy newline-separated system_cfg representation and translate
 * it into the same JSON configuration consumed by modern provisioning.
 */


#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <uci.h>
#include <json-c/json.h>

#include "wlan.h"
#include "ufmodel.h"
#include "crypto.h"
#include "wlan_internal.h"


static int system_cfg_get(const char *cfg, const char *key,
                          char *out, size_t out_size)
{
    size_t key_len = strlen(key);
    const char *line = cfg;

    while (line && *line) {
        const char *end = strchr(line, '\n');
        size_t line_len = end ? (size_t)(end - line) : strlen(line);
        if (line_len > key_len && !strncmp(line, key, key_len) &&
            line[key_len] == '=') {
            size_t value_len = line_len - key_len - 1;
            while (value_len && line[key_len + value_len] == '\r')
                value_len--;
            if (value_len >= out_size) value_len = out_size - 1;
            memcpy(out, line + key_len + 1, value_len);
            out[value_len] = '\0';
            return 1;
        }
        line = end ? end + 1 : NULL;
    }
    return 0;
}

int wlan_apply_system_cfg(const char *system_cfg,
                          const uf_model_t *model)
{
    if (!system_cfg || !system_cfg[0])
        return -1;

    struct json_object *root = json_object_new_object();
    struct json_object *radios = json_object_new_array();
    struct json_object *vaps = json_object_new_array();
    char key[64], value[256];

    for (int i = 1; i <= 4; i++) {
        snprintf(key, sizeof(key), "radio.%d.ieee_mode", i);
        if (!system_cfg_get(system_cfg, key, value, sizeof(value)))
            continue;

        struct json_object *radio = json_object_new_object();
        const char *band = strstr(value, "11na") ? "na" : "ng";
        json_object_object_add(radio, "radio",
                               json_object_new_string(band));

        const char *ht = strstr(value, "ht80") ? "HT80" :
                         strstr(value, "ht40") ? "HT40" : "HT20";
        json_object_object_add(radio, "ht", json_object_new_string(ht));

        snprintf(key, sizeof(key), "radio.%d.channel", i);
        if (system_cfg_get(system_cfg, key, value, sizeof(value)))
            json_object_object_add(radio, "channel",
                json_object_new_int(!strcmp(value, "auto") ? 0 : atoi(value)));

        snprintf(key, sizeof(key), "radio.%d.txpower", i);
        if (system_cfg_get(system_cfg, key, value, sizeof(value)) &&
            strcmp(value, "auto"))
            json_object_object_add(radio, "tx_power",
                                   json_object_new_int(atoi(value)));
        json_object_array_add(radios, radio);
    }

    for (int i = 1; i <= 32; i++) {
        snprintf(key, sizeof(key), "aaa.%d.ssid", i);
        if (!system_cfg_get(system_cfg, key, value, sizeof(value)))
            continue;

        struct json_object *vap = json_object_new_object();
        json_object_object_add(vap, "essid",
                               json_object_new_string(value));

        /* Preserve the WLAN ObjectId used to attach clients in topology. */
        const char *id_suffixes[] = { "id", "_id", "wlanconf_id" };
        for (size_t id_index = 0;
             id_index < sizeof(id_suffixes) / sizeof(id_suffixes[0]);
             id_index++) {
            snprintf(key, sizeof(key), "aaa.%d.%s", i,
                     id_suffixes[id_index]);
            if (system_cfg_get(system_cfg, key, value, sizeof(value)) &&
                wlan_valid_object_id(value)) {
                json_object_object_add(vap, "id", json_object_new_string(value));
                json_object_object_add(vap, "wlanconf_id",
                                       json_object_new_string(value));
                break;
            }
        }

        snprintf(key, sizeof(key), "aaa.%d.status", i);
        if (system_cfg_get(system_cfg, key, value, sizeof(value)) &&
            strcmp(value, "enabled")) {
            json_object_put(vap);
            continue;
        }

        snprintf(key, sizeof(key), "wireless.%d.parent", i);
        const char *band = "ng";
        if (system_cfg_get(system_cfg, key, value, sizeof(value)) &&
            !strcmp(value, "wifi1"))
            band = "na";
        json_object_object_add(vap, "radio", json_object_new_string(band));

        /* UniFi's legacy Force WiFi 4 mode is carried as wireless.N.iot. */
        snprintf(key, sizeof(key), "wireless.%d.iot", i);
        if (system_cfg_get(system_cfg, key, value, sizeof(value)))
            json_object_object_add(vap, "iot", json_object_new_boolean(
                wlan_feature_enabled(value)));

        char passphrase[256] = {0};
        snprintf(key, sizeof(key), "aaa.%d.wpa.psk", i);
        int has_passphrase = system_cfg_get(system_cfg, key, passphrase,
                                            sizeof(passphrase));
        if (!has_passphrase) {
            snprintf(key, sizeof(key), "aaa.%d.sae.psk.1.psk", i);
            has_passphrase = system_cfg_get(system_cfg, key, passphrase,
                                            sizeof(passphrase));
        }

        char key_mgmt[256] = {0};
        snprintf(key, sizeof(key), "aaa.%d.wpa.key.1.mgmt", i);
        int has_key_mgmt = system_cfg_get(system_cfg, key, key_mgmt,
                                          sizeof(key_mgmt));

        int wpa3_support = 0;
        snprintf(key, sizeof(key), "aaa.%d.wpa3.support", i);
        if (system_cfg_get(system_cfg, key, value, sizeof(value)))
            wpa3_support = wlan_feature_enabled(value);

        int wpa3_transition = 0;
        snprintf(key, sizeof(key), "aaa.%d.wpa3.transition", i);
        if (system_cfg_get(system_cfg, key, value, sizeof(value)))
            wpa3_transition = wlan_feature_enabled(value);

        const char *security = "open";
        if (has_key_mgmt && strstr(key_mgmt, "WPA-EAP")) {
            security = wpa3_support ? "wpa3enterprise" : "wpa2enterprise";
        } else if (has_key_mgmt && strstr(key_mgmt, "SAE")) {
            /* A transition BSS permits both WPA2-PSK and SAE. */
            security = wpa3_transition || strstr(key_mgmt, "WPA-PSK")
                       ? "wpa3transition" : "wpa3";
        } else if (has_passphrase) {
            security = "wpa2psk";
        }
        json_object_object_add(vap, "security",
                               json_object_new_string(security));

        int enterprise = !strcmp(security, "wpa2enterprise") ||
                         !strcmp(security, "wpa3enterprise");
        if (has_passphrase && !enterprise) {
            json_object_object_add(vap, "x_passphrase",
                                   json_object_new_string(passphrase));
        }

        if (enterprise) {
            snprintf(key, sizeof(key), "aaa.%d.radius.auth.1.ip", i);
            if (system_cfg_get(system_cfg, key, value, sizeof(value)))
                json_object_object_add(vap, "auth_server",
                                       json_object_new_string(value));

            snprintf(key, sizeof(key), "aaa.%d.radius.auth.1.port", i);
            if (system_cfg_get(system_cfg, key, value, sizeof(value)))
                json_object_object_add(vap, "auth_port",
                                       json_object_new_int(atoi(value)));

            snprintf(key, sizeof(key), "aaa.%d.radius.auth.1.secret", i);
            if (system_cfg_get(system_cfg, key, value, sizeof(value)))
                json_object_object_add(vap, "auth_secret",
                                       json_object_new_string(value));

            snprintf(key, sizeof(key), "aaa.%d.radius.acct.1.ip", i);
            if (system_cfg_get(system_cfg, key, value, sizeof(value)))
                json_object_object_add(vap, "acct_server",
                                       json_object_new_string(value));

            snprintf(key, sizeof(key), "aaa.%d.radius.acct.1.port", i);
            if (system_cfg_get(system_cfg, key, value, sizeof(value)))
                json_object_object_add(vap, "acct_port",
                                       json_object_new_int(atoi(value)));

            snprintf(key, sizeof(key), "aaa.%d.radius.acct.1.secret", i);
            if (system_cfg_get(system_cfg, key, value, sizeof(value)))
                json_object_object_add(vap, "acct_secret",
                                       json_object_new_string(value));
        }

        snprintf(key, sizeof(key), "aaa.%d.hide_ssid", i);
        if (system_cfg_get(system_cfg, key, value, sizeof(value)))
            json_object_object_add(vap, "hide_ssid",
                json_object_new_boolean(!strcmp(value, "true")));

        snprintf(key, sizeof(key), "aaa.%d.ft.status", i);
        if (system_cfg_get(system_cfg, key, value, sizeof(value)))
            json_object_object_add(vap, "fast_roaming_enabled",
                json_object_new_boolean(!strcmp(value, "enabled")));

        const char *band_steer_suffixes[] = {
            "band_steering", "band_steering_enabled", "band_steering_mode",
            "steering"
        };
        for (size_t n = 0;
             n < sizeof(band_steer_suffixes) /
                 sizeof(band_steer_suffixes[0]); n++) {
            snprintf(key, sizeof(key), "aaa.%d.%s", i,
                     band_steer_suffixes[n]);
            if (system_cfg_get(system_cfg, key, value, sizeof(value))) {
                json_object_object_add(vap, "band_steering",
                    json_object_new_boolean(wlan_feature_enabled(value)));
                break;
            }
        }

        const char *handoff_suffixes[] = {
            "bss_transition", "bss_transition_enabled",
            "handoff_suggestions", "handoff_suggestions_enabled"
        };
        for (size_t n = 0;
             n < sizeof(handoff_suffixes) / sizeof(handoff_suffixes[0]); n++) {
            snprintf(key, sizeof(key), "aaa.%d.%s", i,
                     handoff_suffixes[n]);
            if (system_cfg_get(system_cfg, key, value, sizeof(value))) {
                json_object_object_add(vap, "bss_transition",
                    json_object_new_boolean(wlan_feature_enabled(value)));
                break;
            }
        }

        snprintf(key, sizeof(key), "aaa.%d.pmf.mode", i);
        if (system_cfg_get(system_cfg, key, value, sizeof(value))) {
            const char *pmf = !strcmp(value, "2") ? "required" :
                              !strcmp(value, "1") ? "optional" : "disabled";
            json_object_object_add(vap, "pmf_mode",
                                   json_object_new_string(pmf));
        }

        snprintf(key, sizeof(key), "aaa.%d.br.devname", i);
        if (system_cfg_get(system_cfg, key, value, sizeof(value))) {
            const char *dot = strrchr(value, '.');
            if (dot && atoi(dot + 1) > 0)
                json_object_object_add(vap, "vlan_id",
                                       json_object_new_int(atoi(dot + 1)));
        }
        json_object_array_add(vaps, vap);
    }

    json_object_object_add(root, "radio_table", radios);
    json_object_object_add(root, "vap_table", vaps);
    LOGF(stdout, "Parsed legacy system_cfg: %zu radios, %zu VAPs",
         json_object_array_length(radios), json_object_array_length(vaps));
    int result = wlan_apply_config(root, model);
    json_object_put(root);
    return result;
}