// Copyright 2016-2020 Espressif Systems (Shanghai) PTE LTD
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include <stdint.h>
#include <stdio.h>
#include <sys/cdefs.h>
#include "sdkconfig.h"
#include "esp_err.h"
#include "esp_log.h"
#include "esp_console.h"
#include "esp_vfs_dev.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "driver/uart.h"
#include "linenoise/linenoise.h"

static const char *TAG = "console.repl.uart";

#define CONSOLE_PROMPT_MAX_LEN (32)

typedef enum {
    CONSOLE_REPL_STATE_DEINIT,
    CONSOLE_REPL_STATE_INIT,
    CONSOLE_REPL_STATE_START,
} repl_state_t;

typedef struct {
    esp_console_repl_t repl_core;        // base class
    char prompt[CONSOLE_PROMPT_MAX_LEN]; // Prompt to be printed before each line
    repl_state_t state;
    const char *history_save_path;
    TaskHandle_t task_hdl; // REPL task handle
} esp_console_repl_com_t;

typedef struct {
    esp_console_repl_com_t repl_com; // base class
    int uart_channel;                // uart channel number
} esp_console_repl_uart_t;

static void esp_console_repl_task(void *args);
static esp_err_t esp_console_repl_uart_delete(esp_console_repl_t *repl);
static esp_err_t esp_console_common_init(esp_console_repl_com_t *repl_com);
static esp_err_t esp_console_setup_prompt(const char *prompt, esp_console_repl_com_t *repl_com);
static esp_err_t esp_console_setup_history(const char *history_path, uint32_t max_history_len, esp_console_repl_com_t *repl_com);

esp_err_t esp_console_new_repl_uart(const esp_console_dev_uart_config_t *dev_config, const esp_console_repl_config_t *repl_config, esp_console_repl_t **ret_repl)
{
    esp_err_t ret = ESP_OK;
    esp_console_repl_uart_t *uart_repl = NULL;
    if (!repl_config | !dev_config | !ret_repl) {
        ret = ESP_ERR_INVALID_ARG;
        goto _exit;
    }
    // allocate memory for console REPL context
    uart_repl = calloc(1, sizeof(esp_console_repl_uart_t));
    if (!uart_repl) {
        ret = ESP_ERR_NO_MEM;
        goto _exit;
    }

    /* Drain stdout before reconfiguring it */
    fflush(stdout);
    fsync(fileno(stdout));

    /* Disable buffering on stdin */
    setvbuf(stdin, NULL, _IONBF, 0);

    /* Minicom, screen, idf_monitor send CR when ENTER key is pressed */
    esp_vfs_dev_uart_set_rx_line_endings(ESP_LINE_ENDINGS_CR);
    /* Move the caret to the beginning of the next line on '\n' */
    esp_vfs_dev_uart_set_tx_line_endings(ESP_LINE_ENDINGS_CRLF);

    /* Configure UART. Note that REF_TICK is used so that the baud rate remains
     * correct while APB frequency is changing in light sleep mode.
     */
    const uart_config_t uart_config = {
        .baud_rate = dev_config->baud_rate,
        .data_bits = UART_DATA_8_BITS,
        .parity = UART_PARITY_DISABLE,
        .stop_bits = UART_STOP_BITS_1,
        .source_clk = UART_SCLK_REF_TICK,
    };

    uart_param_config(dev_config->channel, &uart_config);
    uart_set_pin(dev_config->channel, dev_config->tx_gpio_num, dev_config->rx_gpio_num, -1, -1);

    /* Install UART driver for interrupt-driven reads and writes */
    ret = uart_driver_install(dev_config->channel, 256, 0, 0, NULL, 0);
    if (ret != ESP_OK) {
        goto _exit;
    }

    /* Tell VFS to use UART driver */
    esp_vfs_dev_uart_use_driver(dev_config->channel);

    // initialize console, common part
    ret = esp_console_common_init(&uart_repl->repl_com);
    if (ret != ESP_OK) {
        goto _exit;
    }

    // setup history
    ret = esp_console_setup_history(repl_config->history_save_path, repl_config->max_history_len, &uart_repl->repl_com);
    if (ret != ESP_OK) {
        goto _exit;
    }

    // setup prompt
    esp_console_setup_prompt(repl_config->prompt, &uart_repl->repl_com);

    /* spawn a single thread to run REPL */
    if (xTaskCreate(esp_console_repl_task, "console_repl", repl_config->task_stack_size,
                    &uart_repl->repl_com, repl_config->task_priority, &uart_repl->repl_com.task_hdl) != pdTRUE) {
        ret = ESP_FAIL;
        goto _exit;
    }

    uart_repl->uart_channel = dev_config->channel;
    uart_repl->repl_com.state = CONSOLE_REPL_STATE_INIT;
    uart_repl->repl_com.repl_core.del = esp_console_repl_uart_delete;
    *ret_repl = &uart_repl->repl_com.repl_core;
    return ESP_OK;
_exit:
    if (uart_repl) {
        esp_console_deinit();
        uart_driver_delete(dev_config->channel);
        free(uart_repl);
    }
    if (ret_repl) {
        *ret_repl = NULL;
    }
    return ret;
}

esp_err_t esp_console_start_repl(esp_console_repl_t *repl)
{
    esp_err_t ret = ESP_OK;
    esp_console_repl_com_t *repl_com = __containerof(repl, esp_console_repl_com_t, repl_core);
    // check if already initialized
    if (repl_com->state != CONSOLE_REPL_STATE_INIT) {
        ret = ESP_ERR_INVALID_STATE;
        goto _exit;
    }

    repl_com->state = CONSOLE_REPL_STATE_START;
    xTaskNotifyGive(repl_com->task_hdl);
    return ESP_OK;
_exit:
    return ret;
}

static esp_err_t esp_console_setup_prompt(const char *prompt, esp_console_repl_com_t *repl_com)
{
    /* set command line prompt */
    const char *prompt_temp = "esp>";
    if (prompt) {
        prompt_temp = prompt;
    }
    snprintf(repl_com->prompt, CONSOLE_PROMPT_MAX_LEN - 1, LOG_COLOR_I "%s " LOG_RESET_COLOR, prompt_temp);

    printf("\r\n"
           "Type 'help' to get the list of commands.\r\n"
           "Use UP/DOWN arrows to navigate through command history.\r\n"
           "Press TAB when typing command name to auto-complete.\r\n");

    /* Figure out if the terminal supports escape sequences */
    int probe_status = linenoiseProbe();
    if (probe_status) {
        /* zero indicates success */
        printf("\r\n"
               "Your terminal application does not support escape sequences.\n\n"
               "Line editing and history features are disabled.\n\n"
               "On Windows, try using Putty instead.\r\n");
        linenoiseSetDumbMode(1);
#if CONFIG_LOG_COLORS
        /* Since the terminal doesn't support escape sequences,
         * don't use color codes in the s_prompt.
         */
        snprintf(repl_com->prompt, CONSOLE_PROMPT_MAX_LEN - 1, "%s ", prompt_temp);
#endif //CONFIG_LOG_COLORS
    }

    return ESP_OK;
}

static esp_err_t esp_console_setup_history(const char *history_path, uint32_t max_history_len, esp_console_repl_com_t *repl_com)
{
    esp_err_t ret = ESP_OK;

    repl_com->history_save_path = history_path;
    if (history_path) {
        /* Load command history from filesystem */
        linenoiseHistoryLoad(history_path);
    }

    /* Set command history size */
    if (linenoiseHistorySetMaxLen(max_history_len) != 1) {
        ESP_LOGE(TAG, "set max history length to %d failed", max_history_len);
        ret = ESP_FAIL;
        goto _exit;
    }
    return ESP_OK;
_exit:
    return ret;
}

static esp_err_t esp_console_common_init(esp_console_repl_com_t *repl_com)
{
    esp_err_t ret = ESP_OK;
    /* Initialize the console */
    esp_console_config_t console_config = ESP_CONSOLE_CONFIG_DEFAULT();
#if CONFIG_LOG_COLORS
    console_config.hint_color = atoi(LOG_COLOR_CYAN);
#endif
    ret = esp_console_init(&console_config);
    if (ret != ESP_OK) {
        goto _exit;
    }

    ret = esp_console_register_help_command();
    if (ret != ESP_OK) {
        goto _exit;
    }

    /* Configure linenoise line completion library */
    /* Enable multiline editing. If not set, long commands will scroll within single line */
    linenoiseSetMultiLine(1);

    /* Tell linenoise where to get command completions and hints */
    linenoiseSetCompletionCallback(&esp_console_get_completion);
    linenoiseSetHintsCallback((linenoiseHintsCallback *)&esp_console_get_hint);

    return ESP_OK;
_exit:
    return ret;
}

static esp_err_t esp_console_repl_uart_delete(esp_console_repl_t *repl)
{
    esp_err_t ret = ESP_OK;
    esp_console_repl_com_t *repl_com = __containerof(repl, esp_console_repl_com_t, repl_core);
    esp_console_repl_uart_t *uart_repl = __containerof(repl_com, esp_console_repl_uart_t, repl_com);
    // check if already de-initialized
    if (repl_com->state == CONSOLE_REPL_STATE_DEINIT) {
        ESP_LOGE(TAG, "already de-initialized");
        ret = ESP_ERR_INVALID_STATE;
        goto _exit;
    }
    repl_com->state = CONSOLE_REPL_STATE_DEINIT;
    esp_console_deinit();
    esp_vfs_dev_uart_use_nonblocking(uart_repl->uart_channel);
    uart_driver_delete(uart_repl->uart_channel);
    free(uart_repl);
_exit:
    return ret;
}

static void esp_console_repl_task(void *args)
{
    esp_console_repl_com_t *repl_com = (esp_console_repl_com_t *)args;
    // waiting for task notify
    ulTaskNotifyTake(pdTRUE, portMAX_DELAY);
    while (repl_com->state == CONSOLE_REPL_STATE_START) {
        char *line = linenoise(repl_com->prompt);
        if (line == NULL) {
            ESP_LOGD(TAG, "empty line");
            /* Ignore empty lines */
            continue;
        }
        /* Add the command to the history */
        linenoiseHistoryAdd(line);
        /* Save command history to filesystem */
        if (repl_com->history_save_path) {
            linenoiseHistorySave(repl_com->history_save_path);
        }

        /* Try to run the command */
        int ret;
        esp_err_t err = esp_console_run(line, &ret);
        if (err == ESP_ERR_NOT_FOUND) {
            printf("Unrecognized command\n");
        } else if (err == ESP_ERR_INVALID_ARG) {
            // command was empty
        } else if (err == ESP_OK && ret != ESP_OK) {
            printf("Command returned non-zero error code: 0x%x (%s)\n", ret, esp_err_to_name(ret));
        } else if (err != ESP_OK) {
            printf("Internal error: %s\n", esp_err_to_name(err));
        }
        /* linenoise allocates line buffer on the heap, so need to free it */
        linenoiseFree(line);
    }
    ESP_LOGD(TAG, "The End");
    vTaskDelete(NULL);
}