/* SPDX-License-Identifier: GPL-3.0-only */
/* Native ESP-IDF Wi-Fi lifecycle and connection policy manager. */

#pragma once

#include <stdbool.h>
#include <stdint.h>

#include "esp_err.h"
#include "esp_wifi_types.h"
#include "wifi_config.h"

#ifdef __cplusplus
extern "C" {
#endif

typedef enum {
    WIFI_MANAGER_STATE_STOPPED = 0,
    WIFI_MANAGER_STATE_STARTING,
    WIFI_MANAGER_STATE_CONNECTING,
    WIFI_MANAGER_STATE_WAITING_IP,
    WIFI_MANAGER_STATE_ONLINE,
    WIFI_MANAGER_STATE_BACKOFF,
    WIFI_MANAGER_STATE_AP_ONLY,
    WIFI_MANAGER_STATE_ERROR,
} wifi_manager_state_t;

typedef struct {
    uint64_t starts;
    uint64_t stops;
    uint64_t applies;
    uint64_t connect_attempts;
    uint64_t associations;
    uint64_t got_ip;
    uint64_t disconnects;
    uint64_t profile_cycles;
    uint64_t retries;
    uint64_t ap_starts;
    uint64_t ap_stops;
    uint64_t client_joins;
    uint64_t client_leaves;
    uint64_t queue_drops;
} wifi_manager_counters_t;

typedef struct {
    bool initialized;
    bool started;
    wifi_manager_state_t state;

    /* -1 means that no station profile is currently being attempted or used. */
    int8_t active_profile;
    uint8_t sta_ssid_len;
    char sta_ssid[WIFI_CONFIG_SSID_MAX_LEN + 1U];
    uint32_t ip;
    uint32_t netmask;
    uint32_t gateway;
    uint8_t sta_channel;
    int8_t sta_rssi;
    wifi_auth_mode_t sta_auth;

    wifi_config_ap_policy_t ap_policy;
    bool ap_running;
    uint8_t ap_ssid_len;
    char ap_ssid[WIFI_CONFIG_SSID_MAX_LEN + 1U];
    uint8_t ap_client_count;
    uint8_t ap_channel;

    uint16_t last_disconnect_reason;
    esp_err_t last_error;
    uint32_t retry_seconds;
    uint32_t config_generation;
    wifi_manager_counters_t counters;
} wifi_manager_snapshot_t;

/* A stale expected working-config generation maps cleanly to HTTP 409. */
#define WIFI_MANAGER_ERR_CONFIG_CONFLICT ESP_ERR_INVALID_VERSION

/*
 * Initializes ESP-NETIF, the default event loop, both default Wi-Fi netifs,
 * Wi-Fi itself, and the permanent policy task. The manager never aborts the
 * application on failure; callers may keep UART/USB services operational.
 */
esp_err_t wifi_manager_init(const wifi_app_config_t *config);

/*
 * Returns a copy of the RAM working configuration, including credentials.
 * The caller owns the returned copy and must securely wipe it after use.
 */
esp_err_t wifi_manager_get_working_config(wifi_app_config_t *config);

/*
 * Atomically copies the credential-bearing working configuration and the exact
 * nonzero generation that identified it. Both outputs are cleared on failure;
 * the caller must securely wipe config after every successful call.
 */
esp_err_t wifi_manager_get_working_config_versioned(wifi_app_config_t *config,
                                                    uint32_t *generation);


/*
 * Atomically replace the complete validated working configuration only when
 * expected_generation still identifies the current configuration. A stale
 * expectation returns WIFI_MANAGER_ERR_CONFIG_CONFLICT without queueing a
 * restart or changing state. resulting_generation is optional and is set to
 * zero on failure. Generation exhaustion returns ESP_ERR_INVALID_STATE.
 */
esp_err_t wifi_manager_compare_exchange_working_config(
    const wifi_app_config_t *config, uint32_t expected_generation,
    uint32_t *resulting_generation);

/*
 * Persist exactly the working configuration identified by expected_generation.
 * All config writers are excluded through the NVS operation. A stale
 * expectation returns WIFI_MANAGER_ERR_CONFIG_CONFLICT. Generation exhaustion
 * returns ESP_ERR_INVALID_STATE. The saved generation is not incremented because
 * the RAM working configuration is unchanged.
 */
esp_err_t wifi_manager_save_working_config_if_generation(
    uint32_t expected_generation);

/* Lifecycle requests are asynchronous and serialized by the manager task. */
esp_err_t wifi_manager_start(void);
esp_err_t wifi_manager_stop(void);
esp_err_t wifi_manager_reconnect(void);
/* Advance to the next enabled station profile in priority order, wrapping safely. */
esp_err_t wifi_manager_next_profile(void);
/* Reannounce the configured hostname when the manager currently has a STA IP. */
esp_err_t wifi_manager_mdns_reannounce(void);

/* Snapshot data never contains station or AP passwords. */
esp_err_t wifi_manager_get_snapshot(wifi_manager_snapshot_t *snapshot);
esp_err_t wifi_manager_clear_counters(void);

const char *wifi_manager_state_to_string(wifi_manager_state_t state);

#ifdef __cplusplus
}
#endif