#include "ble.h"
#include "state.h"
#include "nimble/nimble_port.h"
#include "nimble/nimble_port_freertos.h"
#include "services/gap/ble_svc_gap.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include <string.h>
#include <stdio.h>

volatile int  g_ble_scanning;
volatile int  g_ble_initialized;
uint8_t       g_own_addr_type;
uint8_t       g_own_addr[6];
uint8_t       g_player_id = 0xFF;
volatile int  g_reset_requested;
int           g_reset_cmd_ticks;

static int ble_gap_event_handler(struct ble_gap_event *event, void *arg);

static void ble_adv_start_internal(void)
{
    ble_payload_t payload;
    payload.magic[0]   = BLE_MFR_MAGIC_0;
    payload.magic[1]   = BLE_MFR_MAGIC_1;
    payload.game_id[0] = g_game_id[0];
    payload.game_id[1] = g_game_id[1];
    memcpy(payload.name, g_player_name, PLAYER_NAME_LEN);
    payload.life       = (int16_t)g_life;
    payload.poison     = (uint8_t)g_counters[0];
    payload.eliminated = (uint8_t)g_eliminated;
    payload.player_id  = g_player_id;
    payload.reset_cmd  = (g_reset_cmd_ticks > 0) ? 1 : 0;
    for (int i = 0; i < MAX_OPPONENTS; i++)
        payload.cmdr_dmg[i] = (uint8_t)g_cmdr_damage[i];

    static uint8_t mfr[2 + sizeof(ble_payload_t)];
    mfr[0] = 0xFF; mfr[1] = 0xFF;
    memcpy(mfr + 2, &payload, sizeof(payload));

    struct ble_hs_adv_fields fields = {0};
    fields.mfg_data     = mfr;
    fields.mfg_data_len = sizeof(mfr);
    ble_gap_adv_set_fields(&fields);

    struct ble_gap_adv_params params = {0};
    params.conn_mode = BLE_GAP_CONN_MODE_NON;
    params.disc_mode = BLE_GAP_DISC_MODE_NON;
    params.itvl_min  = 0x0320; // 500ms
    params.itvl_max  = 0x0320;
    ble_gap_adv_start(g_own_addr_type, NULL, BLE_HS_FOREVER, &params, ble_gap_event_handler, NULL);

#ifdef DEBUG
    printf("DBG ADV_TX name=%-8.8s life=%d poison=%u game_id=%02X%02X eliminated=%u pid=%u reset=%u\n",
           payload.name, (int)payload.life, (unsigned)payload.poison,
           payload.game_id[0], payload.game_id[1], (unsigned)payload.eliminated,
           (unsigned)payload.player_id, (unsigned)payload.reset_cmd);
    fflush(stdout);
#endif
}

void ble_adv_update(void)
{
    if (!g_ble_initialized || g_ble_scanning) return;
    ble_gap_adv_stop();
    if (g_ble_enabled) ble_adv_start_internal();
}

static void ble_update_peer(const ble_addr_t *addr, const ble_payload_t *p)
{
    if (p->game_id[0] != g_game_id[0] || p->game_id[1] != g_game_id[1]) return;

    int slot = -1;
    for (int i = 0; i < MAX_BLE_PEERS; i++) {
        if (g_peers[i].active && memcmp(&g_peers[i].addr, addr, sizeof(ble_addr_t)) == 0) {
            slot = i; break;
        }
    }
    if (slot < 0) {
        for (int i = 0; i < MAX_BLE_PEERS; i++) {
            if (!g_peers[i].active) { slot = i; break; }
        }
        if (slot < 0) {
            slot = 0;
            for (int i = 1; i < MAX_BLE_PEERS; i++)
                if (g_peers[i].last_seen < g_peers[slot].last_seen) slot = i;
        }
    }
    uint8_t prev_reset_cmd   = g_peers[slot].reset_cmd;
    g_peers[slot].addr       = *addr;
    g_peers[slot].life       = p->life;
    g_peers[slot].poison     = p->poison;
    g_peers[slot].eliminated = p->eliminated;
    g_peers[slot].player_id  = p->player_id;
    g_peers[slot].reset_cmd  = p->reset_cmd;
    memcpy(g_peers[slot].cmdr_dmg, p->cmdr_dmg, MAX_OPPONENTS);
    g_peers[slot].last_seen  = g_tick;
    g_peers[slot].active     = 1;
    memcpy(g_peers[slot].name, p->name, PLAYER_NAME_LEN);
    g_peers[slot].name[PLAYER_NAME_LEN] = '\0';
    if (p->reset_cmd && !prev_reset_cmd) g_reset_requested = 1;

#ifdef DEBUG
    printf("DBG PEER_RX slot=%d addr=%02X:%02X:%02X:%02X:%02X:%02X name=%-8.8s life=%d poison=%u game_id=%02X%02X eliminated=%u pid=%u reset=%u cmdr=[%u,%u,%u,%u]\n",
           slot,
           addr->val[5], addr->val[4], addr->val[3],
           addr->val[2], addr->val[1], addr->val[0],
           p->name, (int)p->life, (unsigned)p->poison,
           p->game_id[0], p->game_id[1], (unsigned)p->eliminated,
           (unsigned)p->player_id, (unsigned)p->reset_cmd,
           (unsigned)p->cmdr_dmg[0], (unsigned)p->cmdr_dmg[1],
           (unsigned)p->cmdr_dmg[2], (unsigned)p->cmdr_dmg[3]);
    fflush(stdout);
#endif
}

static int ble_gap_event_handler(struct ble_gap_event *event, void *arg)
{
    if (event->type == BLE_GAP_EVENT_DISC) {
        const uint8_t *adv_data = event->disc.data;
        int len = event->disc.length_data;
        int i = 0;
        while (i < len) {
            uint8_t adlen  = adv_data[i];
            if (adlen == 0 || i + adlen >= len) break;
            uint8_t adtype = adv_data[i+1];
            if (adtype == 0xFF && adlen >= 1 + 2 + (int)sizeof(ble_payload_t)) {
                const uint8_t *payload_ptr = adv_data + i + 4;
                if (payload_ptr[0] == BLE_MFR_MAGIC_0 && payload_ptr[1] == BLE_MFR_MAGIC_1) {
                    ble_update_peer(&event->disc.addr, (const ble_payload_t *)payload_ptr);
                }
            }
            i += 1 + adlen;
        }
    } else if (event->type == BLE_GAP_EVENT_DISC_COMPLETE) {
        g_ble_scanning = 0;
        if (g_ble_enabled) ble_adv_start_internal();
    }
    return 0;
}

static void ble_on_sync(void)
{
    ble_hs_id_infer_auto(0, &g_own_addr_type);
    ble_hs_id_copy_addr(g_own_addr_type, g_own_addr, NULL);
    if (g_player_id == 0xFF) g_player_id = 0;
    g_ble_initialized = 1;
    if (g_ble_enabled) ble_adv_start_internal();
}

static void ble_on_reset(int reason) { (void)reason; }

static void ble_host_task(void *arg)
{
    nimble_port_run();
    nimble_port_freertos_deinit();
}

static void ble_manager_task(void *arg)
{
    while (!g_ble_initialized) vTaskDelay(pdMS_TO_TICKS(100));
    while (1) {
        vTaskDelay(pdMS_TO_TICKS(10000));
        if (!g_ble_enabled || g_ble_scanning) continue;

        g_ble_scanning = 1;
        ble_gap_adv_stop();

        struct ble_gap_disc_params disc_params = {0};
        disc_params.itvl = 0x0100; disc_params.window = 0x0080; disc_params.passive = 1;
        int rc = ble_gap_disc(g_own_addr_type, 5000, &disc_params, ble_gap_event_handler, NULL);
        if (rc != 0) {
            g_ble_scanning = 0;
            if (g_ble_enabled) ble_adv_start_internal();
        }
        vTaskDelay(pdMS_TO_TICKS(6000));
        if (g_ble_scanning) {
            ble_gap_disc_cancel();
            g_ble_scanning = 0;
            if (g_ble_enabled) ble_adv_start_internal();
        }
    }
}

void player_id_resolve(void)
{
    if (!g_ble_initialized || !g_ble_enabled) return;
    for (int i = 0; i < MAX_BLE_PEERS; i++) {
        if (!g_peers[i].active || g_peers[i].player_id != g_player_id) continue;
        int we_lose = 0;
        for (int b = 5; b >= 0; b--) {
            if (g_peers[i].addr.val[b] < g_own_addr[b]) { we_lose = 1; break; }
            if (g_peers[i].addr.val[b] > g_own_addr[b]) break;
        }
        if (!we_lose) continue;
        uint8_t used[BLE_MAX_PLAYERS] = {0};
        for (int j = 0; j < MAX_BLE_PEERS; j++)
            if (g_peers[j].active && g_peers[j].player_id < BLE_MAX_PLAYERS)
                used[g_peers[j].player_id] = 1;
        for (int id = 0; id < BLE_MAX_PLAYERS; id++) {
            if (!used[id]) { g_player_id = (uint8_t)id; break; }
        }
        ble_adv_update();
        break;
    }
}

void ble_init(void)
{
    nimble_port_init();
    ble_hs_cfg.sync_cb  = ble_on_sync;
    ble_hs_cfg.reset_cb = ble_on_reset;
    ble_svc_gap_init();
    nimble_port_freertos_init(ble_host_task);
    xTaskCreate(ble_manager_task, "ble_mgr", 4096, NULL, 5, NULL);
}