/**
 * Copyright (c) 2021 OpenLens Authors
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of
 * this software and associated documentation files (the "Software"), to deal in
 * the Software without restriction, including without limitation the rights to
 * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
 * the Software, and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
 * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
 * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

import { KubeConfig, V1Node, V1Pod } from "@kubernetes/client-node";
import fse from "fs-extra";
import path from "path";
import os from "os";
import yaml from "js-yaml";
import logger from "../main/logger";
import { ExecValidationNotFoundError } from "./custom-errors";
import { Cluster, Context, newClusters, newContexts, newUsers, User } from "@kubernetes/client-node/dist/config_types";
import { resolvePath } from "./utils";
import Joi from "joi";
import which from "which";

export type KubeConfigValidationOpts = {
  validateCluster?: boolean;
  validateUser?: boolean;
  validateExec?: boolean;
};

export const kubeConfigDefaultPath = path.join(os.homedir(), ".kube", "config");

export function loadConfigFromFileSync(filePath: string): ConfigResult {
  const content = fse.readFileSync(resolvePath(filePath), "utf-8");

  return loadConfigFromString(content);
}

export async function loadConfigFromFile(filePath: string): Promise<ConfigResult> {
  const content = await fse.readFile(resolvePath(filePath), "utf-8");

  return loadConfigFromString(content);
}

const clusterSchema = Joi.object({
  name: Joi
    .string()
    .min(1)
    .required(),
  cluster: Joi
    .object({
      server: Joi
        .string()
        .min(1)
        .required(),
    })
    .required(),
});

const userSchema = Joi.object({
  name: Joi.string()
    .min(1)
    .required(),
});

const contextSchema = Joi.object({
  name: Joi.string()
    .min(1)
    .required(),
  context: Joi.object({
    cluster: Joi.string()
      .min(1)
      .required(),
    user: Joi.string()
      .min(1)
      .required(),
  }),
});

const kubeConfigSchema = Joi
  .object({
    users: Joi
      .array()
      .items(userSchema)
      .optional(),
    clusters: Joi
      .array()
      .items(clusterSchema)
      .optional(),
    contexts: Joi
      .array()
      .items(contextSchema)
      .optional(),
    "current-context": Joi
      .string()
      .min(1)
      .optional(),
  })
  .required();

export interface KubeConfigOptions {
  clusters: Cluster[];
  users: User[];
  contexts: Context[];
  currentContext?: string;
}

export interface OptionsResult {
  options: KubeConfigOptions;
  error: Joi.ValidationError;
}

function loadToOptions(rawYaml: string): OptionsResult {
  const parsed = yaml.safeLoad(rawYaml);
  const { error } = kubeConfigSchema.validate(parsed, {
    abortEarly: false,
    allowUnknown: true,
  });
  const { value } = kubeConfigSchema.validate(parsed, {
    abortEarly: false,
    allowUnknown: true,
    stripUnknown: {
      arrays: true,
    }
  });
  const { clusters: rawClusters, users: rawUsers, contexts: rawContexts, "current-context": currentContext } = value ?? {};
  const clusters = newClusters(rawClusters);
  const users = newUsers(rawUsers);
  const contexts = newContexts(rawContexts);

  return {
    options: { clusters, users, contexts, currentContext },
    error,
  };
}

export function loadFromOptions(options: KubeConfigOptions): KubeConfig {
  const kc = new KubeConfig();

  // need to load using the kubernetes client to generate a kubeconfig object
  kc.loadFromOptions(options);

  return kc;
}

export interface ConfigResult {
  config: KubeConfig;
  error: Joi.ValidationError;
}

export function loadConfigFromString(content: string): ConfigResult {
  const { options, error } = loadToOptions(content);

  return {
    config: loadFromOptions(options),
    error,
  };
}

export interface SplitConfigEntry {
  config: KubeConfig,
  error?: string;
}

/**
 * Breaks kube config into several configs. Each context as it own KubeConfig object
 */
export function splitConfig(kubeConfig: KubeConfig): SplitConfigEntry[] {
  const { contexts = [] } = kubeConfig;

  return contexts.map(context => {
    const config = new KubeConfig();

    config.clusters = [kubeConfig.getCluster(context.cluster)].filter(Boolean);
    config.users = [kubeConfig.getUser(context.user)].filter(Boolean);
    config.contexts = [kubeConfig.getContextObject(context.name)].filter(Boolean);
    config.setCurrentContext(context.name);

    return {
      config,
      error: validateKubeConfig(config, context.name)?.toString(),
    };
  });
}

export function dumpConfigYaml(kubeConfig: Partial<KubeConfig>): string {
  const config = {
    apiVersion: "v1",
    kind: "Config",
    preferences: {},
    "current-context": kubeConfig.currentContext,
    clusters: kubeConfig.clusters.map(cluster => {
      return {
        name: cluster.name,
        cluster: {
          "certificate-authority-data": cluster.caData,
          "certificate-authority": cluster.caFile,
          server: cluster.server,
          "insecure-skip-tls-verify": cluster.skipTLSVerify
        }
      };
    }),
    contexts: kubeConfig.contexts.map(context => {
      return {
        name: context.name,
        context: {
          cluster: context.cluster,
          user: context.user,
          namespace: context.namespace
        }
      };
    }),
    users: kubeConfig.users.map(user => {
      return {
        name: user.name,
        user: {
          "client-certificate-data": user.certData,
          "client-certificate": user.certFile,
          "client-key-data": user.keyData,
          "client-key": user.keyFile,
          "auth-provider": user.authProvider,
          exec: user.exec,
          token: user.token,
          username: user.username,
          password: user.password
        }
      };
    })
  };

  logger.debug("Dumping KubeConfig:", config);

  // skipInvalid: true makes dump ignore undefined values
  return yaml.safeDump(config, { skipInvalid: true });
}

export function podHasIssues(pod: V1Pod) {
  // Logic adapted from dashboard
  const notReady = !!pod.status.conditions.find(condition => {
    return condition.type == "Ready" && condition.status !== "True";
  });

  return (
    notReady ||
    pod.status.phase !== "Running" ||
    pod.spec.priority > 500000 // We're interested in high priority pods events regardless of their running status
  );
}

export function getNodeWarningConditions(node: V1Node) {
  return node.status?.conditions?.filter(c =>
    c.status.toLowerCase() === "true" && c.type !== "Ready" && c.type !== "HostUpgrades"
  ) ?? [];
}

/**
 * Checks if `config` has valid `Context`, `User`, `Cluster`, and `exec` fields (if present when required)
 *
 * Note: This function returns an error instead of throwing it, returning `undefined` if the validation passes
 */
export function validateKubeConfig(config: KubeConfig, contextName: string, validationOpts: KubeConfigValidationOpts = {}): Error | undefined {
  try {
    // we only receive a single context, cluster & user object here so lets validate them as this
    // will be called when we add a new cluster to Lens

    const { validateUser = true, validateCluster = true, validateExec = true } = validationOpts;

    const contextObject = config.getContextObject(contextName);

    // Validate the Context Object
    if (!contextObject) {
      return new Error(`No valid context object provided in kubeconfig for context '${contextName}'`);
    }

    // Validate the Cluster Object
    if (validateCluster && !config.getCluster(contextObject.cluster)) {
      return new Error(`No valid cluster object provided in kubeconfig for context '${contextName}'`);
    }

    const user = config.getUser(contextObject.user);

    // Validate the User Object
    if (validateUser && !user) {
      return new Error(`No valid user object provided in kubeconfig for context '${contextName}'`);
    }

    // Validate exec command if present
    if (validateExec && user?.exec) {
      try {
        which.sync(user.exec.command);

        // If this doesn't throw an error it also means that it has found the executable.
      } catch (error) {
        switch (error?.code) {
          case "ENOENT":
            return new ExecValidationNotFoundError(user.exec.command);
          default:
            return error;
        }
      }
    }

    return undefined;
  } catch (error) {
    return error;
  }
}