/*---------------------------------------------------------------------------------------------
 *  Copyright (c) Microsoft Corporation. All rights reserved.
 *  Licensed under the MIT License. See License.txt in the project root for license information.
 *--------------------------------------------------------------------------------------------*/

import { CommaChar, docComment, EOL, indent } from '@azure-tools/codegen';
import { Abstract, Access, Async, Extern, Modifier, New, Override, Sealed, Static, Virtual } from './access-modifier';
import { Class } from './class';
import { summary, xmlize } from './doc-comments';

import { Expression, toExpression, valueOf, isAnExpression, ExpressionOrLiteral } from './expression';
import { Parameter } from './parameter';
import { StatementPossibilities, Statements } from './statements/statement';
import { TypeDeclaration } from './type-declaration';

const Void = {
  declaration: 'void'
};

export class Method extends Statements {
  public parameters = new Array<Parameter>();
  public 'new': New = Modifier.None;
  public access = Access.Public;
  public 'static': Static = Modifier.None;
  public virtual: Virtual = Modifier.None;
  public sealed: Sealed = Modifier.None;
  public override: Override = Modifier.None;
  public abstract: Abstract = Modifier.None;
  public extern: Extern = Modifier.None;
  public async: Async = Modifier.None;
  public isPartial = false;
  public description = '';
  public returnsDescription = '';
  public body?: StatementPossibilities | Expression;

  constructor(public name: string, protected returnType: TypeDeclaration = Void, objectIntializer?: Partial<Method>) {
    super();
    this.apply(objectIntializer);
    // easy access to allow statements in the initalizer.

    if (this.body && !isAnExpression(this.body)) {
      this.add(this.body);
    }

    if (!this.description.trim()) {
      this.description = '';
    }
    if (!this.returnsDescription.trim()) {
      this.returnsDescription = '';
    }
  }

  public addParameter(parameter: Parameter): Parameter {
    this.parameters.push(parameter);
    return parameter;
  }

  protected get summaryDocumentation(): string {
    return docComment(summary(this.description));
  }

  protected get parameterDocumentation(): string {
    return docComment(this.parameters.joinWith(p => p.comment, EOL));
  }

  protected get returnsDocumentation(): string {
    if (this.returnType.declaration !== 'void') {
      return docComment(xmlize('returns', this.returnsDescription));
    }
    return '';
  }

  public get declaration(): string {
    const parameterDeclaration = this.parameters.joinWith(p => p.declaration, CommaChar);
    const doccomment = `${this.summaryDocumentation}
${this.parameterDocumentation}
${this.returnsDocumentation}`.replace(/\s*\n/g, '\n').replace(/\n+/g, '\n').trim();
    return `${doccomment}
${this.new}${this.access} ${this.static} ${this.virtual} ${this.sealed} ${this.override} ${this.abstract} ${this.extern} ${this.async} ${this.returnType.declaration} ${this.name}(${parameterDeclaration})
`.slim();
  }

  public get interfaceDeclaration(): string {
    const parameterDeclaration = this.parameters.joinWith(p => p.declaration, CommaChar);
    const doccomment = `${this.summaryDocumentation}
${this.parameterDocumentation}
${this.returnsDocumentation}`.replace(/\s*\n/g, '\n').replace(/\n+/g, '\n').trim();
    return `${doccomment}
${this.returnType.declaration} ${this.name}(${parameterDeclaration});
`.slim();
  }

  public get implementation(): string {
    if (isAnExpression(this.body)) {
      return `
${this.declaration} => ${this.body.value};
`.trim();
    }
    return `
${this.declaration}
{
${indent(super.implementation)}
}`.trim();
  }

  public invoke(...parameters: Array<ExpressionOrLiteral>): Expression {
    return toExpression(`${this.name}(${parameters.joinWith(valueOf)})`);
  }
  public addTo(parent: Class): Method {
    parent.addMethod(this);
    return this;
  }
}

export class PartialMethod extends Method {
  public isPartial = true;
  constructor(name: string, returnType: TypeDeclaration = Void, objectIntializer?: Partial<PartialMethod>) {
    super(name, returnType);
    this.access = Access.Default;
    this.apply(objectIntializer);
  }

  public get declaration(): string {
    const parameterDeclaration = this.parameters.joinWith(p => p.declaration, CommaChar);
    return `
${this.summaryDocumentation}
${this.parameterDocumentation}
${this.returnsDocumentation}
partial ${this.new}${this.access} ${this.static} ${this.virtual} ${this.sealed} ${this.override} ${this.abstract} ${this.extern} ${this.async} ${this.returnType.declaration} ${this.name}(${parameterDeclaration})
`.slim();
  }

  public get implementation(): string {
    return `${this.declaration};`.slim();
  }
}

export class LambdaMethod extends Method {
  constructor(name: string, returnType: TypeDeclaration = Void, protected expression: Expression, objectIntializer?: Partial<PartialMethod>) {
    super(name, returnType);
    this.apply(objectIntializer);
  }

  public get declaration(): string {
    const parameterDeclaration = this.parameters.joinWith(p => p.declaration, CommaChar);
    return `
${this.summaryDocumentation}
${this.parameterDocumentation}
${this.returnsDocumentation}
${this.new}${this.access} ${this.static} ${this.virtual} ${this.sealed} ${this.override} ${this.abstract} ${this.extern} ${this.async} ${this.returnType.declaration} ${this.name}(${parameterDeclaration}) => ${valueOf(this.expression)}
`.slim();
  }

  public get implementation(): string {
    return `${this.declaration};`.slim();
  }
}

export class ImplicitCastOperator extends Method {
  constructor(targetType: TypeDeclaration, sourceType: TypeDeclaration, protected expression: ExpressionOrLiteral, objectIntializer?: Partial<ImplicitCastOperator>) {
    super(`implicit operator ${targetType.declaration}`, targetType, { parameters: [new Parameter('source', sourceType)], static: Modifier.Static, });
  }

  public get declaration(): string {
    const parameterDeclaration = this.parameters.joinWith(p => p.declaration, CommaChar);
    return `
${this.summaryDocumentation}
${this.parameterDocumentation}
${this.returnsDocumentation}
${this.new}${this.access} static ${this.override} ${this.abstract} implicit operator ${this.returnType.declaration}(${parameterDeclaration}) => ${valueOf(this.expression)}
`.slim();
  }

  public get implementation(): string {
    return `${this.declaration};`.slim();
  }
}