import CodeGenerator from "apollo-codegen-core/lib/utilities/CodeGenerator";

import { join, wrap } from "apollo-codegen-core/lib/utilities/printing";

export interface Class {
  className: string;
  modifiers: string[];
  superClass?: string;
  adoptedProtocols?: string[];
}

export interface Struct {
  structName: string;
  adoptedProtocols?: string[];
  description?: string;
}

export interface Protocol {
  protocolName: string;
  adoptedProtocols?: string[];
}

export interface Property {
  propertyName: string;
  typeName: string;
  isOptional?: boolean;
  description?: string;
}

export function escapedString(string: string) {
  return string.replace(/"/g, '\\"').replace(/\n/g, "\\n");
}

// prettier-ignore
const reservedKeywords = new Set(['associatedtype', 'class', 'deinit', 'enum', 'extension',
  'fileprivate', 'func', 'import', 'init', 'inout', 'internal', 'let', 'open',
  'operator', 'private', 'protocol', 'public', 'static', 'struct', 'subscript',
  'typealias', 'var', 'break', 'case', 'continue', 'default', 'defer', 'do',
  'else', 'fallthrough', 'for', 'guard', 'if', 'in', 'repeat', 'return',
  'switch', 'where', 'while', 'as', 'Any', 'catch', 'false', 'is', 'nil',
  'rethrows', 'super', 'self', 'Self', 'throw', 'throws', 'true', 'try',
  'associativity', 'convenience', 'dynamic', 'didSet', 'final', 'get', 'infix',
  'indirect', 'lazy', 'left', 'mutating', 'none', 'nonmutating', 'optional',
  'override', 'postfix', 'precedence', 'prefix', 'Protocol', 'required', 'right',
  'set', 'Type', 'unowned', 'weak', 'willSet']);

export function escapeIdentifierIfNeeded(identifier: string) {
  if (reservedKeywords.has(identifier)) {
    return "`" + identifier + "`";
  } else {
    return identifier;
  }
}

export class SwiftGenerator<Context> extends CodeGenerator<
  Context,
  { typeName: string }
> {
  constructor(context: Context) {
    super(context);
  }

  multilineString(string: string) {
    this.printOnNewline(`"${escapedString(string)}"`);
  }

  comment(comment?: string) {
    comment &&
      comment.split("\n").forEach(line => {
        this.printOnNewline(`/// ${line.trim()}`);
      });
  }

  deprecationAttributes(
    isDeprecated: boolean | undefined,
    deprecationReason: string | undefined
  ) {
    if (isDeprecated !== undefined && isDeprecated) {
      deprecationReason =
        deprecationReason !== undefined && deprecationReason.length > 0
          ? deprecationReason
          : "";
      this.printOnNewline(
        `@available(*, deprecated, message: "${escapedString(
          deprecationReason
        )}")`
      );
    }
  }

  namespaceDeclaration(namespace: string | undefined, closure: Function) {
    if (namespace) {
      this.printNewlineIfNeeded();
      this.printOnNewline(`/// ${namespace} namespace`);
      this.printOnNewline(`public enum ${namespace}`);
      this.pushScope({ typeName: namespace });
      this.withinBlock(closure);
      this.popScope();
    } else {
      if (closure) {
        closure();
      }
    }
  }

  namespaceExtensionDeclaration(
    namespace: string | undefined,
    closure: Function
  ) {
    if (namespace) {
      this.printNewlineIfNeeded();
      this.printOnNewline(`/// ${namespace} namespace`);
      this.printOnNewline(`public extension ${namespace}`);
      this.pushScope({ typeName: namespace });
      this.withinBlock(closure);
      this.popScope();
    } else {
      if (closure) {
        closure();
      }
    }
  }

  classDeclaration(
    { className, modifiers, superClass, adoptedProtocols = [] }: Class,
    closure: Function
  ) {
    this.printNewlineIfNeeded();
    this.printOnNewline(
      wrap("", join(modifiers, " "), " ") + `class ${className}`
    );
    this.print(wrap(": ", join([superClass, ...adoptedProtocols], ", ")));
    this.pushScope({ typeName: className });
    this.withinBlock(closure);
    this.popScope();
  }

  structDeclaration(
    { structName, description, adoptedProtocols = [] }: Struct,
    closure: Function
  ) {
    this.printNewlineIfNeeded();
    this.comment(description);
    this.printOnNewline(
      `public struct ${escapeIdentifierIfNeeded(structName)}`
    );
    this.print(wrap(": ", join(adoptedProtocols, ", ")));
    this.pushScope({ typeName: structName });
    this.withinBlock(closure);
    this.popScope();
  }

  propertyDeclaration({ propertyName, typeName, description }: Property) {
    this.comment(description);
    this.printOnNewline(
      `public var ${escapeIdentifierIfNeeded(propertyName)}: ${typeName}`
    );
  }

  propertyDeclarations(properties: Property[]) {
    if (!properties) return;
    properties.forEach(property => this.propertyDeclaration(property));
  }

  protocolDeclaration(
    { protocolName, adoptedProtocols }: Protocol,
    closure: Function
  ) {
    this.printNewlineIfNeeded();
    this.printOnNewline(`public protocol ${protocolName}`);
    this.print(wrap(": ", join(adoptedProtocols, ", ")));
    this.pushScope({ typeName: protocolName });
    this.withinBlock(closure);
    this.popScope();
  }

  protocolPropertyDeclaration({ propertyName, typeName }: Property) {
    this.printOnNewline(`var ${propertyName}: ${typeName} { get }`);
  }

  protocolPropertyDeclarations(properties: Property[]) {
    if (!properties) return;
    properties.forEach(property => this.protocolPropertyDeclaration(property));
  }
}