#include <stdlib.h>
#include <string.h>

#include "cJSON/cJSON.h"
#include "json_rpc.h"
#include "log.h"
#include "pawn_lsp.h"

#define PAWN_LSP_VESRION "v0.0.1"
#define PAWN_LSP_NAME "pawn_lsp"


static int _request_handler(json_rpc_request_t *req, cJSON **resp, void *arg);
static void _notify_handler(json_rpc_request_t *req, void *arg);

static int _initialize(json_rpc_request_t *req, cJSON **resp, void *arg);
static int _shutdown(json_rpc_request_t *req, cJSON **resp, void *arg);

static void _exit_notf(json_rpc_request_t *req, void *arg);

int
pawn_lsp_init(pawn_lsp_t *pawn,
              json_rpc_t *jrpc,
              const char *pawncc,
              char **pawn_args,
              int pawn_argc)
{
    pawn->jrpc = jrpc;
    pawn->pawncc = strdup(pawncc);

    /* execv(pawncc <filename> -d0 -v=2 -o/tmp/... [...args] <NULL>)*/
    pawn->pawn_args = calloc(pawn_argc + 5, sizeof(char *));
    /* pawn->pawn_args[0] = <filename>, set when compiling */
    pawn->pawn_args[1] = strdup("-d0");
    pawn->pawn_args[2] = strdup("-v=2");
    /* pawn->pawn_args[3] = -o/tmp/..., set when compiling */
    for (int i = 0; i < pawn_argc; i++) {
        pawn->pawn_args[i + 4] = strdup(pawn_args[i]);
    }

    json_rpc_set_request_handler(jrpc, _request_handler, &pawn);
    json_rpc_set_notify_handler(jrpc, _notify_handler, &pawn);

    return (0);
}

void
pawn_lsp_deinit(pawn_lsp_t *pawn)
{
    free(pawn->pawncc);
    for (int i = 0; pawn->pawn_args[i] != NULL; i++) {
        free(pawn->pawn_args[i]);
    }
    free(pawn->pawn_args);
}

static int
_request_handler(json_rpc_request_t *req, cJSON **resp, void *arg)
{
    char *method = req->method->valuestring;

    log_info("Handle request \"%s\"\r\n", method);

    if (!strcmp(method, "initialize")) {
        return _initialize(req, resp, arg);
    } else if (!strcmp(method, "shutdown")) {
        return _shutdown(req, resp, arg);
    } else {
        log_warn("Unrecognized request method\r\n");
        (*resp) = cJSON_CreateNull();
        return (-1);
    }
}

static void
_notify_handler(json_rpc_request_t *req, void *arg)
{
    char *method = req->method->valuestring;

    log_info("Handle notification \"%s\"\r\n", method);

    if (!strcmp(method, "exit")) {
        _exit_notf(req, arg);
    } else {
        log_warn("Unrecognized notification method\r\n");
    }
}


int
_initialize(json_rpc_request_t *req, cJSON **resp, void *arg)
{
    cJSON *val;

    (*resp) = cJSON_CreateObject();

    val = cJSON_AddObjectToObject((*resp), "capabilities");
    if (val == NULL) {
        return (-1);
    }

    if (cJSON_AddStringToObject(val, "positionEncoding", "utf-8") == NULL) {
        return (-1);
    }

    val = cJSON_AddObjectToObject((*resp), "serverInfo");
    if (val == NULL) {
        return (-1);
    }

    if ((cJSON_AddStringToObject(val, "name", PAWN_LSP_NAME) == NULL) ||
        (cJSON_AddStringToObject(val, "version", PAWN_LSP_VESRION) == NULL)) {
        return (-1);
    }

    return (0);
}

static int
_shutdown(json_rpc_request_t *req, cJSON **resp, void *arg)
{
    (*resp) = cJSON_CreateNull();
    return (0);
}

static void
_exit_notf(json_rpc_request_t *req, void *arg)
{
    pawn_lsp_t *pawn = arg;
    json_rpc_cancel(pawn->jrpc);
}