import {isPresent, isBlank} from 'angular2/src/facade/lang';
import {BaseException} from 'angular2/src/facade/exceptions';

import * as o from '../output/output_ast';
import {
  CompileTokenMetadata,
  CompileDirectiveMetadata,
  CompileIdentifierMetadata
} from '../compile_metadata';
import {CompileView} from './compile_view';
import {Identifiers} from '../identifiers';

export function getPropertyInView(property: o.Expression, callingView: CompileView,
                                  definedView: CompileView): o.Expression {
  if (callingView === definedView) {
    return property;
  } else {
    var viewProp: o.Expression = o.THIS_EXPR;
    var currView: CompileView = callingView;
    while (currView !== definedView && isPresent(currView.declarationElement.view)) {
      currView = currView.declarationElement.view;
      viewProp = viewProp.prop('parent');
    }
    if (currView !== definedView) {
      throw new BaseException(
          `Internal error: Could not calculate a property in a parent view: ${property}`);
    }
    if (property instanceof o.ReadPropExpr) {
      let readPropExpr: o.ReadPropExpr = property;
      // Note: Don't cast for members of the AppView base class...
      if (definedView.fields.some((field) => field.name == readPropExpr.name) ||
          definedView.getters.some((field) => field.name == readPropExpr.name)) {
        viewProp = viewProp.cast(definedView.classType);
      }
    }
    return o.replaceVarInExpression(o.THIS_EXPR.name, viewProp, property);
  }
}

export function injectFromViewParentInjector(token: CompileTokenMetadata,
                                             optional: boolean): o.Expression {
  var args = [createDiTokenExpression(token)];
  if (optional) {
    args.push(o.NULL_EXPR);
  }
  return o.THIS_EXPR.prop('parentInjector').callMethod('get', args);
}

export function getViewFactoryName(component: CompileDirectiveMetadata,
                                   embeddedTemplateIndex: number): string {
  return `viewFactory_${component.type.name}${embeddedTemplateIndex}`;
}


export function createDiTokenExpression(token: CompileTokenMetadata): o.Expression {
  if (isPresent(token.value)) {
    return o.literal(token.value);
  } else if (token.identifierIsInstance) {
    return o.importExpr(token.identifier)
        .instantiate([], o.importType(token.identifier, [], [o.TypeModifier.Const]));
  } else {
    return o.importExpr(token.identifier);
  }
}

export function createFlatArray(expressions: o.Expression[]): o.Expression {
  var lastNonArrayExpressions = [];
  var result: o.Expression = o.literalArr([]);
  for (var i = 0; i < expressions.length; i++) {
    var expr = expressions[i];
    if (expr.type instanceof o.ArrayType) {
      if (lastNonArrayExpressions.length > 0) {
        result =
            result.callMethod(o.BuiltinMethod.ConcatArray, [o.literalArr(lastNonArrayExpressions)]);
        lastNonArrayExpressions = [];
      }
      result = result.callMethod(o.BuiltinMethod.ConcatArray, [expr]);
    } else {
      lastNonArrayExpressions.push(expr);
    }
  }
  if (lastNonArrayExpressions.length > 0) {
    result =
        result.callMethod(o.BuiltinMethod.ConcatArray, [o.literalArr(lastNonArrayExpressions)]);
  }
  return result;
}

export function createPureProxy(fn: o.Expression, argCount: number, pureProxyProp: o.ReadPropExpr,
                                view: CompileView) {
  view.fields.push(new o.ClassField(pureProxyProp.name, null));
  var pureProxyId =
      argCount < Identifiers.pureProxies.length ? Identifiers.pureProxies[argCount] : null;
  if (isBlank(pureProxyId)) {
    throw new BaseException(`Unsupported number of argument for pure functions: ${argCount}`);
  }
  view.createMethod.addStmt(
      o.THIS_EXPR.prop(pureProxyProp.name).set(o.importExpr(pureProxyId).callFn([fn])).toStmt());
}