import chalk from "chalk";
import axios from "axios";
import equal from "deep-equal";
import path from "path";
import {
  Bundle,
  bundle,
  databaseEntryPoints,
  actionsEntryPoints,
  actionsDir,
} from "../../bundler/index.js";
import { version } from "../../index.js";
import axiosRetry from "axios-retry";
import {
  deprecationCheckWarning,
  formatSize,
  functionsDir,
  fatalServerErr,
} from "./utils.js";
export { provisionHost, productionProvisionHost } from "./utils.js";
import { Context } from "./context.js";

/** Type representing auth configuration. */
export interface AuthInfo {
  // Provider-specific application identifier. Corresponds to the `aud` field in an OIDC token.
  applicationID: string;
  // Domain used for authentication. Corresponds to the `iss` field in an OIDC token.
  domain: string;
}

/** Type representing Convex project configuration. */
export interface ProjectConfig {
  project: string;
  team: string;
  prodUrl: string;
  functions: string;
  authInfo: AuthInfo[];
}

export interface Config {
  projectConfig: ProjectConfig;
  modules: Bundle[];
  udfServerVersion?: string;
}

/** Check if object is of AuthInfo type. */
function isAuthInfo(object: any): object is AuthInfo {
  return (
    "applicationID" in object &&
    typeof object.applicationID === "string" &&
    "domain" in object &&
    typeof object.domain === "string"
  );
}

function isAuthInfos(object: any): object is AuthInfo[] {
  return Array.isArray(object) && object.every((item: any) => isAuthInfo(item));
}

/** Error parsing ProjectConfig representation. */
class ParseError extends Error {}

/** Parse object to ProjectConfig. */
export function parseProjectConfig(obj: any): ProjectConfig {
  if (typeof obj !== "object") {
    throw new ParseError("Expected an object");
  }
  if (typeof obj.team !== "string") {
    if (obj.instanceName && obj.origin) {
      // This is likely a convex.json generated 0.1.8 or older.
      throw new ParseError(
        'If upgrading from convex 0.1.8 or below, please delete "convex.json" and reinitialize using `npx convex reinit`'
      );
    }
    throw new ParseError("Expected team to be a string");
  }
  if (typeof obj.project !== "string") {
    throw new ParseError("Expected project to be a string");
  }
  if (typeof obj.prodUrl !== "string") {
    throw new ParseError("Expected prodUrl to be a string");
  }
  if (typeof obj.functions !== "string") {
    throw new ParseError("Expected functions to be a string");
  }

  // Allow the `authInfo` key to be omitted, treating it as an empty list of providers.
  obj.authInfo = obj.authInfo ?? [];
  if (!isAuthInfos(obj.authInfo)) {
    throw new ParseError("Expected authInfo to be type AuthInfo[]");
  }

  // Important! We return the object itself (not a new object) because
  // we want to ensure that fields we're unaware of are "passed through".
  // It's possible that this is an old client and the server knows about new
  // fields that we don't.
  return obj;
}

/** Parse a deployment config returned by the backend. */
function parseBackendConfig(obj: any): {
  functions: string;
  authInfo: AuthInfo[];
} {
  if (typeof obj !== "object") {
    throw new ParseError("Expected an object");
  }
  if (typeof obj.functions !== "string") {
    throw new ParseError("Expected functions to be a string");
  }

  // Allow the `authInfo` key to be omitted, treating it as an empty list of providers.
  obj.authInfo = obj.authInfo ?? [];
  if (!isAuthInfos(obj.authInfo)) {
    throw new ParseError("Expected authInfo to be type AuthInfo[]");
  }

  // Important! We return the object itself (not a new object) because
  // we want to ensure that fields we're unaware of are "passed through".
  // It's possible that this is an old client and the server knows about new
  // fields that we don't.
  return obj;
}

export function configName(): string {
  return "convex.json";
}

export async function configFilepath(ctx: Context): Promise<string> {
  const configFn = configName();
  // We used to allow src/convex.json, but no longer (as of 10/7/2022).
  // Leave an error message around to help people out. We can remove this
  // error message after a couple months.
  const preferredLocation = configFn;
  const wrongLocation = path.join("src", configFn);

  // Allow either location, but not both.
  const preferredLocationExists = ctx.fs.exists(preferredLocation);
  const wrongLocationExists = ctx.fs.exists(wrongLocation);
  if (preferredLocationExists && wrongLocationExists) {
    console.error(
      chalk.red(
        `Error: both ${preferredLocation} and ${wrongLocation} files exist!`
      )
    );
    console.error(`Consolidate these and remove ${wrongLocation}.`);
    return await ctx.fatalError(1, "fs");
  }
  if (!preferredLocationExists && wrongLocationExists) {
    console.error(
      chalk.red(
        `Error: Please move ${wrongLocation} to the root of your project`
      )
    );
    return await ctx.fatalError(1, "fs");
  }

  return preferredLocation;
}

/** Read configuration from a local `convex.json` file. */
export async function readProjectConfig(ctx: Context): Promise<{
  projectConfig: ProjectConfig;
  configPath: string;
}> {
  let projectConfig;
  const configPath = await configFilepath(ctx);
  try {
    projectConfig = parseProjectConfig(
      JSON.parse(ctx.fs.readUtf8File(configPath))
    );
  } catch (err) {
    if (err instanceof ParseError || err instanceof SyntaxError) {
      console.error(chalk.red(`Error: Parsing "${configPath}" failed`));
      console.error(chalk.gray(err.toString()));
    } else {
      console.error(
        chalk.red(`Error: Unable to read project config file "${configPath}"`)
      );
      console.error(
        "Are you running this command from the root directory of a Convex project?"
      );
      if (err instanceof Error) {
        console.error(chalk.gray(err.message));
      }
    }
    return await ctx.fatalError(1, "fs", err);
  }
  return {
    projectConfig,
    configPath,
  };
}

/**
 * Given an {@link ProjectConfig}, add in the bundled modules to produce the
 * complete config.
 */
export async function configFromProjectConfig(
  ctx: Context,
  projectConfig: ProjectConfig,
  configPath: string,
  verbose: boolean
): Promise<Config> {
  let modules;
  try {
    const baseDir = functionsDir(configPath, projectConfig);
    // We bundle functions entry points separately since they execute on different
    // platforms.
    const entryPoints = await databaseEntryPoints(ctx.fs, baseDir, verbose);
    modules = await bundle(ctx.fs, baseDir, entryPoints, true, "browser");
    if (verbose) {
      console.log(
        "Queries and mutations modules: ",
        modules.map(m => m.path)
      );
    }

    // Bundle actions.
    const nodeEntryPoints = await actionsEntryPoints(ctx.fs, baseDir, verbose);
    const nodeModules = await bundle(
      ctx.fs,
      baseDir,
      nodeEntryPoints,
      true,
      "node",
      path.join(actionsDir, "_deps")
    );
    if (verbose) {
      console.log(
        "Actions modules: ",
        nodeModules.map(m => m.path)
      );
    }
    modules.push(...nodeModules);
  } catch (err) {
    console.error(chalk.red("Error: Unable to bundle Convex modules"));
    if (err instanceof Error) {
      console.error(chalk.gray(err.message));
    }
    return await ctx.fatalError(1, "fs", err);
  }

  return {
    projectConfig: projectConfig,
    modules: modules,
    // We're just using the version this CLI is running with for now.
    // This could be different than the version of `convex` the app runs with
    // if the CLI is installed globally.
    udfServerVersion: version,
  };
}

/**
 * Read the config from `convex.json` and bundle all the modules.
 */
export async function readConfig(
  ctx: Context,
  verbose: boolean
): Promise<{ config: Config; configPath: string }> {
  const { projectConfig, configPath } = await readProjectConfig(ctx);
  const config = await configFromProjectConfig(
    ctx,
    projectConfig,
    configPath,
    verbose
  );
  return { config, configPath };
}

/** Write the config to `convex.json` in the current working directory. */
export async function writeProjectConfig(
  ctx: Context,
  projectConfig: ProjectConfig
) {
  const configPath = await configFilepath(ctx);
  try {
    const contents = JSON.stringify(projectConfig, undefined, 2) + "\n";
    ctx.fs.writeUtf8File(configPath, contents, 0o644);
  } catch (err) {
    console.error(
      chalk.red(
        `Error: Unable to write project config file "${configPath}" in current directory`
      )
    );
    console.error(
      "Are you running this command from the root directory of a Convex project?"
    );
    return await ctx.fatalError(1, "fs", err);
  }
  ctx.fs.mkdir(functionsDir(configPath, projectConfig), {
    allowExisting: true,
  });
}

/** Pull configuration from the given remote origin. */
export async function pullConfig(
  ctx: Context,
  project: string,
  team: string,
  origin: string,
  adminKey: string
): Promise<Config> {
  const client = axios.create();
  axiosRetry(client, {
    retries: 4,
    retryDelay: axiosRetry.exponentialDelay,
    retryCondition: error => {
      return error.response?.status == 404 || false;
    },
  });
  try {
    const res = await client.post(
      `${origin}/api/${version}/get_config`,
      { version, adminKey },
      {
        maxContentLength: Infinity,
      }
    );
    deprecationCheckWarning(ctx, res);
    const { functions, authInfo } = parseBackendConfig(res.data.config);
    const projectConfig = {
      project,
      team,
      prodUrl: origin,
      functions,
      authInfo,
    };
    return {
      projectConfig,
      modules: res.data.modules,
      udfServerVersion: res.data.udfServerVersion,
    };
  } catch (err) {
    console.error(
      chalk.red("Error: Unable to pull deployment config from", origin)
    );
    return await fatalServerErr(ctx, err);
  }
}

export function configJSON(config: Config, adminKey: string) {
  // Override origin with the url
  const projectConfig = {
    projectSlug: config.projectConfig.project,
    teamSlug: config.projectConfig.team,
    functions: config.projectConfig.functions,
    authInfo: config.projectConfig.authInfo,
  };
  return {
    config: projectConfig,
    modules: config.modules,
    udfServerVersion: config.udfServerVersion,
    adminKey,
  };
}

/** Push configuration to the given remote origin. */
export async function pushConfig(
  ctx: Context,
  config: Config,
  adminKey: string,
  url: string
): Promise<void> {
  const serializedConfig = configJSON(config, adminKey);
  try {
    await axios.post(`${url}/api/${version}/push_config`, serializedConfig, {
      maxContentLength: Infinity,
      maxBodyLength: Infinity,
    });
  } catch (err) {
    console.error(chalk.red("Error: Unable to push deployment config to", url));
    return await fatalServerErr(ctx, err);
  }
}

type Files = { source: string; filename: string }[];

export type CodegenResponse =
  | {
      success: true;
      files: Files;
    }
  | {
      success: false;
      error: string;
    };

function renderModule(module: Bundle): string {
  const sourceMapSize = formatSize(module.sourceMap?.length ?? 0);
  return (
    module.path +
    ` (${formatSize(module.source.length)}, source map ${sourceMapSize})`
  );
}

function compareModules(oldModules: Bundle[], newModules: Bundle[]): string {
  let diff = "";

  const droppedModules = [];
  for (const oldModule of oldModules) {
    let matches = false;
    for (const newModule of newModules) {
      if (
        oldModule.path === newModule.path &&
        oldModule.source === newModule.source &&
        oldModule.sourceMap === newModule.sourceMap
      ) {
        matches = true;
        break;
      }
    }
    if (!matches) {
      droppedModules.push(oldModule);
    }
  }
  if (droppedModules.length > 0) {
    diff += "Delete the following modules:\n";
    for (const module of droppedModules) {
      diff += "[-] " + renderModule(module) + "\n";
    }
  }

  const addedModules = [];
  for (const newModule of newModules) {
    let matches = false;
    for (const oldModule of oldModules) {
      if (
        oldModule.path === newModule.path &&
        oldModule.source === newModule.source &&
        oldModule.sourceMap === newModule.sourceMap
      ) {
        matches = true;
        break;
      }
    }
    if (!matches) {
      addedModules.push(newModule);
    }
  }
  if (addedModules.length > 0) {
    diff += "Add the following modules:\n";
    for (const module of addedModules) {
      diff += "[+] " + renderModule(module) + "\n";
    }
  }

  return diff;
}

/** Generate a human-readable diff between the two configs. */
export function diffConfig(oldConfig: Config, newConfig: Config): string {
  let diff = compareModules(oldConfig.modules, newConfig.modules);

  const droppedAuth = [];
  for (const oldAuth of oldConfig.projectConfig.authInfo) {
    let matches = false;
    for (const newAuth of newConfig.projectConfig.authInfo) {
      if (equal(oldAuth, newAuth)) {
        matches = true;
        break;
      }
    }
    if (!matches) {
      droppedAuth.push(oldAuth);
    }
  }
  if (droppedAuth.length > 0) {
    diff += "Remove the following auth providers:\n";
    for (const authInfo of droppedAuth) {
      diff += "[-] " + JSON.stringify(authInfo) + "\n";
    }
  }

  const addedAuth = [];
  for (const newAuth of newConfig.projectConfig.authInfo) {
    let matches = false;
    for (const oldAuth of oldConfig.projectConfig.authInfo) {
      if (equal(newAuth, oldAuth)) {
        matches = true;
        break;
      }
    }
    if (!matches) {
      addedAuth.push(newAuth);
    }
  }
  if (addedAuth.length > 0) {
    diff += "Add the following auth providers:\n";
    for (const auth of addedAuth) {
      diff += "[+] " + JSON.stringify(auth) + "\n";
    }
  }

  let versionMessage = "";
  const matches = oldConfig.udfServerVersion === newConfig.udfServerVersion;
  if (oldConfig.udfServerVersion && (!newConfig.udfServerVersion || !matches)) {
    versionMessage += `[-] ${oldConfig.udfServerVersion}\n`;
  }
  if (newConfig.udfServerVersion && (!oldConfig.udfServerVersion || !matches)) {
    versionMessage += `[+] ${newConfig.udfServerVersion}\n`;
  }
  if (versionMessage) {
    diff += "Change the server's function version:\n";
    diff += versionMessage;
  }

  return diff;
}