//#define LOG_LOCAL_LEVEL ESP_LOG_DEBUG

#include <utils.h>
#include <stdlib.h>
#include <esp_log.h>
#include <driver/uart.h>
#include <errno.h>
#include <esp_vfs_dev.h>
#include <fcntl.h>
#include <settings.h>
#include "console_ioimpl.h"
#include "tasks.h"
#include "telnet_parser.h"
#include "cmd_common.h"

static const char *TAG = "console-io";

void console_internal_error_print(const char *msg) {
    ESP_LOGE(TAG, "CONSOLE ERR: %s", msg);
}

void console_setup_uart_stdio(void)
{
    assert(CONFIG_ESP_CONSOLE_UART_NUM == UART_NUM_0);

    /* Minicom, screen, idf_monitor send CR when ENTER key is pressed */
    esp_vfs_dev_uart_port_set_rx_line_endings(UART_NUM_0, ESP_LINE_ENDINGS_CR);
    /* Move the caret to the beginning of the next line on '\n' */
    esp_vfs_dev_uart_port_set_tx_line_endings(UART_NUM_0, ESP_LINE_ENDINGS_CRLF); // this is the default anyway

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

//    fcntl(STDIN_FILENO, F_SETFL, O_NONBLOCK); // make input non-blocking

#if 0
    /* 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 = CONFIG_CONSOLE_UART_BAUDRATE,
            .data_bits = UART_DATA_8_BITS,
            .parity = UART_PARITY_DISABLE,
            .stop_bits = UART_STOP_BITS_1,
            .use_ref_tick = true
    };
    ESP_ERROR_CHECK( uart_param_config(CONFIG_CONSOLE_UART_NUM, &uart_config) );
#endif

    /* Install UART driver for interrupt-driven reads and writes */
    ESP_ERROR_CHECK(uart_driver_install(CONFIG_ESP_CONSOLE_UART_NUM,
        /* rxbuf */ 256, /* txbuf */ 0, /* que */ 0, /* uart que */ NULL, /* alloc flags */ 0));

    uart_flush(CONFIG_ESP_CONSOLE_UART_NUM);

    /* Tell VFS to use UART driver */
    esp_vfs_dev_uart_use_driver(CONFIG_ESP_CONSOLE_UART_NUM);
}

static void my_console_task_freertos(void *param) {
    console_ctx_t *ctx = param;
    assert(CONSOLE_CTX_MAGIC == ctx->__internal_magic); // just make sure it's OK

    vTaskDelay(pdMS_TO_TICKS(50)); // ??

    bool logged_in = true;
    {
        struct console_ioimpl *io = ctx->ioctx;
        assert(CONSOLE_IOIMPL_MAGIC == io->__magic);

        if (io->kind == CONSOLE_IO_TELNET) {
            const size_t pwlen = strnlen(gSettings.console_pw, CONSOLE_PW_LEN);
            if (pwlen != 0) {
                ESP_LOGE(TAG, "Pw=\"%.*s\"", pwlen, gSettings.console_pw);

                console_print_ctx(&io->ctx, "Password: ");

                // Make the prompt fancy with asterisks and stuff. Backspace is not supported.
                int pos = 0;
                char buf[CONSOLE_PW_LEN] = {/*zeros*/};
                while (1) {
                    char ch = 0;
                    console_read_ctx(ctx, &ch, 1);
                    if (ch == 10 || ch == 13) {
                        console_write_ctx(ctx, "\n", 1);
                        break;
                    }
                    if (ch >= 32 && ch <= 126) {
                        if (pos < CONSOLE_PW_LEN) {
                            buf[pos++] = ch;
                        }
                        console_write_ctx(ctx, "*", 1);
                    }
                }

                if (0 == strncmp(buf, gSettings.console_pw, CONSOLE_PW_LEN)) {
                    console_print_ctx(&io->ctx, "Login OK!\n");
                } else {
                    console_print_ctx(&io->ctx, "Login failed!\n");
                    logged_in = false;
                    if (io->telnet.tcpcli) {
                        tcpd_kick(io->telnet.tcpcli);
                    }
                }
            }
        }
    }

    if (logged_in) {
        console_print_motd(ctx);
        console_task(param);
    }

    ESP_LOGD(TAG, "Console task ended");

    // This delay should ensure the TCP client is shut down completely
    // before we proceed to free stuff. The delay is deliberately very generous,
    // we are in no rush here.
    vTaskDelay(pdMS_TO_TICKS(2000));

    // Deallocate what console allocated inside ctx, ctx is part of ioimpl so it will NOT be freed
    ESP_LOGD(TAG, "Clear console context");
    console_ctx_destroy(ctx);

    ESP_LOGD(TAG, "Clear IO context");
    struct console_ioimpl *io = ctx->ioctx;
    assert(CONSOLE_IOIMPL_MAGIC == io->__magic);

    // Tear down IO
    if (io->kind == CONSOLE_IO_TELNET) {
        vRingbufferDelete(io->telnet.console_stdin_ringbuf);
    }

    // Free ioimpl
    free(io);

    ESP_LOGI(TAG, "Console task shutdown.");
    // suicide the task
    vTaskDelete(NULL);
}

static void telnet_shutdown_handler(console_ctx_t *ctx) {
    assert(ctx);
    assert(CONSOLE_CTX_MAGIC == ctx->__internal_magic); // just make sure it's OK
    struct console_ioimpl *io = ctx->ioctx;
    assert(io);
    assert(CONSOLE_IOIMPL_MAGIC == io->__magic);

    tcpd_kick(io->telnet.tcpcli);
}

/**
 * Start console working with stdin and stdout
 */
static esp_err_t console_start_io(struct console_ioimpl **pIo, TaskHandle_t * hdl, enum console_iokind kind, TcpdClient_t client) {
    struct console_ioimpl * io = calloc(1, sizeof(struct console_ioimpl));
    if (io == NULL) {
        return ESP_ERR_NO_MEM;
    }
    if (pIo != NULL) {
        *pIo = io;
    }

    io->__magic = CONSOLE_IOIMPL_MAGIC;

    io->kind = kind;

    if (kind == CONSOLE_IO_TELNET) {
        io->telnet.console_stdin_ringbuf = xRingbufferCreate(CONSOLE_BUFSIZE, RINGBUF_TYPE_BYTEBUF);
        if (NULL == io->telnet.console_stdin_ringbuf) {
            ESP_LOGE(TAG, "Failed to create RB!");
            free(io);
            if (pIo != NULL) {
                *pIo = NULL;
            }
            return ESP_ERR_NO_MEM;
        }
        io->telnet.tcpcli = client;

        // Store the "io" reference as "cctx" in the TCP client, so we know
        //  where to write received data in the callback
        tcpd_set_client_ctx(client, io);

    } else {
        io->files.inf = stdin;
        io->files.outf = stdout;
    }

    // using "static" allocation - context is part of the io struct
    // Here "io" is stored as "ioctx" in "ctx" and then passed to the read/write functions
    if (NULL == console_ctx_init(&io->ctx, io)) {
        ESP_LOGE(TAG, "Console init failed!");
        goto fail;
    }

    if (kind == CONSOLE_IO_FILES) {
        io->ctx.exit_allowed = false;
    } else {
        /* TELNET */
        io->ctx.shutdown_handler = telnet_shutdown_handler;
    }

    assert(io->ctx.__internal_magic == CONSOLE_CTX_MAGIC);

    snprintf(io->ctx.prompt, CONSOLE_PROMPT_MAX_LEN, "\x1b[36;1m> \x1b[m");

    if (pdPASS != xTaskCreate(
        my_console_task_freertos, // func
        "console", // name
        CONSOLE_TASK_STACK, // stack
        &io->ctx, // param
        CONSOLE_TASK_PRIO, // prio
        hdl // handle dest
    )) {
        ESP_LOGE(TAG, "Err create console task!");
        goto fail;
    }

    return ESP_OK;

fail:
    ESP_LOGE(TAG, "console_start_io FAILED, freeing resources!");
    console_ctx_destroy(&io->ctx);

    if (kind == CONSOLE_IO_TELNET) {
        vRingbufferDelete(io->telnet.console_stdin_ringbuf);
        io->telnet.console_stdin_ringbuf = NULL;
    }

    free(io);
    if (pIo != NULL) {
        *pIo = NULL;
    }
    return ESP_FAIL;
}

esp_err_t console_start_stdio(struct console_ioimpl **pIo, TaskHandle_t * hdl) {
    ESP_LOGI(TAG, "Start STDIO console task");

    return console_start_io(pIo, hdl, CONSOLE_IO_FILES, NULL);
}

esp_err_t console_start_tcp(struct console_ioimpl **pIo, TaskHandle_t * hdl, TcpdClient_t client) {
    ESP_LOGI(TAG, "Start TCP console task");

    return console_start_io(pIo, hdl, CONSOLE_IO_TELNET, client);
}

/**
 * Write to console context.
 *
 * Return number of characters written, -1 on error.
 */
int console_write_ctx(console_ctx_t *ctx, const char *text, size_t len) {
    struct console_ioimpl *io = ctx->ioctx;
    assert(CONSOLE_IOIMPL_MAGIC == io->__magic);

    if (io->kind == CONSOLE_IO_TELNET) {
        const char *wp = (const char *)text;
        const char *sp = (const char *)text;
        int towrite = 0;

        // hack to allow using bare \n
        for (size_t i = 0; i < len; i++) {
            char c = *sp++;
            if (c == '\n') {
                // LF: print the chunk before it and a CR.
                if (towrite > 0) {
                    if (ESP_OK != tcpd_send(io->telnet.tcpcli, (uint8_t *) wp, towrite)) {
                        return -1;
                    }
                }
                if (ESP_OK != tcpd_send(io->telnet.tcpcli, (uint8_t*) "\r", 1)) {
                    return -1;
                }
                // The LF gets rolled into the next chunk.
                wp = sp - 1;
                towrite = 1;
            } else {
                // Non-LF character is printed as is
                towrite++;
            }
        }

        // Send the leftovers (chars from last LF or from the start)
        if (towrite > 0) {
            if (ESP_OK != tcpd_send(io->telnet.tcpcli, (uint8_t*) wp, towrite)) {
                return -1;
            }
        }

        return len;
    } else {
        // File IO
        errno = 0;
        // the UART driver takes care of encoding \n as \r\n
        size_t n = fwrite(text, 1, len, io->files.outf);
        if (n != len) {
            if (errno || ferror(io->files.outf)) {
                return -1;
            }
        }
        return n;
    }
}

/**
 * Read from console context's input stream.
 *
 * Return number of characters read, -1 on error
 */
int console_read_ctx(console_ctx_t *ctx, char *dest, size_t count) {
    if (!console_have_stdin_ctx(ctx)) {
        ESP_LOGW(TAG, "Console stream has no stdin!");
        return -1;
    }

    struct console_ioimpl *io = ctx->ioctx;
    assert(CONSOLE_IOIMPL_MAGIC == io->__magic);

    if (io->kind == CONSOLE_IO_TELNET) {
        size_t remain = count;
        char *wp = dest;
        do {
            size_t rcount = 0;
            uint8_t *chunk = xRingbufferReceiveUpTo(io->telnet.console_stdin_ringbuf, &rcount, portMAX_DELAY, remain);

            // telnet options negotiation
            rcount = telnet_middleware_read(ctx, chunk, rcount);

            if (rcount > 0) {
                memcpy(wp, chunk, rcount);
                wp += rcount;
                remain -= rcount;
            }

            vRingbufferReturnItem(io->telnet.console_stdin_ringbuf, chunk);
        } while (remain > 0);

        return count;
    } else {
        // File IO
        errno = 0;
//        clearerr(io->files.inf);
        size_t r = fread(dest, 1, count, io->files.inf);

        if (errno != 0 || feof(io->files.inf) /*|| ferror(io->files.inf)*/) {
            ESP_LOGW(TAG, "Console stream EOF or error.");
            perror("Read err");
            return -1;
        }

        return r;
    }
}

/**
 * Check if console input stream has bytes ready.
 *
 * @return number of queued bytes, 0 if none, -1 on error.
 */
int console_can_read_ctx(console_ctx_t *ctx) {
    if (!console_have_stdin_ctx(ctx)) {
        ESP_LOGW(TAG, "Console stream has no stdin!");
        return -1;
    }

    struct console_ioimpl *io = ctx->ioctx;
    assert(CONSOLE_IOIMPL_MAGIC == io->__magic);

    if (io->kind == CONSOLE_IO_TELNET) {
        uint32_t nitems = 0;
        vRingbufferGetInfo(io->telnet.console_stdin_ringbuf, NULL, NULL, NULL, NULL, &nitems);
        return nitems;
    } else {
        // File IO

        // a hack with select - this is used rarely, we can afford the overhead
        fd_set readfds;
        FD_ZERO(&readfds);
        FD_SET(fileno(io->files.inf), &readfds);
        struct timeval timeout = {0, 0};
        int sel_rv = select(1, &readfds, NULL, NULL, &timeout);
        if (sel_rv > 0) {
            return 1; // at least one
        } else if (sel_rv == -1) {
            ESP_LOGW(TAG, "Console stream EOF or error.");
            return -1; // error
        } else {
            return 0; // nothing
        }
    }
}

/**
 * Test if console context is not NULL and has stdin stream available
 *
 * @return have stdin
 */
bool console_have_stdin_ctx(console_ctx_t *ctx) {
    if (!ctx->ioctx) return false;
    struct console_ioimpl *io = ctx->ioctx;
    assert(CONSOLE_IOIMPL_MAGIC == io->__magic);

    if (io->kind == CONSOLE_IO_TELNET) {
        return io->telnet.tcpcli != NULL &&
            io->telnet.console_stdin_ringbuf != NULL;
    } else {
        // File IO
//        ESP_LOGW(TAG, "%p, %d, %d", io->files.inf,
//                                    feof(io->files.inf),
//                                    ferror(io->files.inf));

        return io->files.inf != NULL &&
            !feof(io->files.inf);
    }
}