#include "mesh_sdk.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

static void say(json_t *m) {
    json_object_set_new(m, "jsonrpc", json_string("2.0"));
    char *text = json_dumps(m, JSON_COMPACT);
    fprintf(stdout, "%s\n", text);
    fflush(stdout);
    free(text);
    json_decref(m);
}

static json_t *as_schema(json_t *given) {
    if (!given || !json_is_object(given) || json_object_size(given) == 0)
        return json_pack("{s:s,s:{}}", "type", "object", "properties");
    if (json_object_get(given, "type") || json_object_get(given, "properties"))
        return json_incref(given);
    return json_pack("{s:s,s:O}", "type", "object", "properties", given);
}

int mesh_serve(const char *name, const mesh_tool *tools, size_t count) {
    char *line = NULL;
    size_t cap = 0;
    ssize_t got;
    while ((got = getline(&line, &cap, stdin)) >= 0) {
        json_error_t err;
        json_t *req = json_loads(line, 0, &err);
        if (!req) continue;
        json_t *id = json_object_get(req, "id");
        const char *method = json_string_value(json_object_get(req, "method"));
        json_t *params = json_object_get(req, "params");
        if (!method) { json_decref(req); continue; }
        if (strcmp(method, "initialize") == 0) {
            say(json_pack("{s:O,s:{s:s,s:{s:{}},s:{s:s,s:s}}}", "id", id ? id : json_null(), "result",
                "protocolVersion", MESH_SDK_PROTOCOL, "capabilities", "tools",
                "serverInfo", "name", name, "version", "1"));
        } else if (strcmp(method, "notifications/initialized") == 0) {
        } else if (strcmp(method, "ping") == 0) {
            if (id) say(json_pack("{s:O,s:{}}", "id", id, "result"));
        } else if (strcmp(method, "tools/list") == 0) {
            json_t *listed = json_array();
            for (size_t i = 0; i < count; i++)
                json_array_append_new(listed, json_pack("{s:s,s:s,s:o}", "name", tools[i].name,
                    "description", tools[i].description, "inputSchema", as_schema(tools[i].input)));
            say(json_pack("{s:O,s:{s:o}}", "id", id ? id : json_null(), "result", "tools", listed));
        } else if (strcmp(method, "tools/call") == 0) {
            const char *wanted = params ? json_string_value(json_object_get(params, "name")) : NULL;
            const mesh_tool *tool = NULL;
            for (size_t i = 0; wanted && i < count; i++)
                if (strcmp(tools[i].name, wanted) == 0) tool = &tools[i];
            if (!tool) {
                char message[256];
                snprintf(message, sizeof message, "%s has no tool %s", name, wanted ? wanted : "");
                say(json_pack("{s:O,s:{s:i,s:s}}", "id", id ? id : json_null(), "error", "code", -32602, "message", message));
            } else {
                json_t *args = params ? json_object_get(params, "arguments") : NULL;
                json_t *empty = args ? NULL : json_object();
                char *error = NULL;
                json_t *result = tool->run(args ? args : empty, &error);
                if (empty) json_decref(empty);
                if (result) {
                    char *text = json_dumps(result, JSON_COMPACT);
                    say(json_pack("{s:O,s:{s:[{s:s,s:s}]}}", "id", id ? id : json_null(), "result", "content", "type", "text", "text", text));
                    free(text);
                    json_decref(result);
                } else {
                    say(json_pack("{s:O,s:{s:[{s:s,s:s}],s:b}}", "id", id ? id : json_null(), "result", "content",
                        "type", "text", "text", error ? error : "the tool failed", "isError", 1));
                    free(error);
                }
            }
        } else if (id) {
            char message[256];
            snprintf(message, sizeof message, "no %s", method);
            say(json_pack("{s:O,s:{s:i,s:s}}", "id", id, "error", "code", -32601, "message", message));
        }
        json_decref(req);
    }
    free(line);
    return ferror(stdin) ? -1 : 0;
}