import ts from "typescript";

import { ExpressionFactory } from "../../factories/ExpressionFactory";
import { IdentifierFactory } from "../../factories/IdentifierFactory";
import { StatementFactory } from "../../factories/StatementFactory";
import { TypeFactory } from "../../factories/TypeFactory";

import { MetadataArray } from "../../schemas/metadata/MetadataArray";
import { MetadataArrayType } from "../../schemas/metadata/MetadataArrayType";
import { MetadataTuple } from "../../schemas/metadata/MetadataTuple";

import { CheckerProgrammer } from "../CheckerProgrammer";
import { FeatureProgrammer } from "../FeatureProgrammer";
import { UnionExplorer } from "../helpers/UnionExplorer";

/**
 * @internal
 */
export const check_union_array_like =
  <Origin, Category extends MetadataArray | MetadataTuple, Element>(
    accessor: check_union_array_like.IAccessor<Origin, Category, Element>,
  ) =>
  (props: check_union_array_like.IProps<Category, Element>) =>
  (parameters: ts.ParameterDeclaration[]) =>
  (
    input: ts.Expression,
    origins: Origin[],
    explore: FeatureProgrammer.IExplore,
  ): ts.ArrowFunction => {
    // ONLY ONE TYPE
    const targets: Array<Category> = origins.map(accessor.transform);
    if (targets.length === 1)
      return ts.factory.createArrowFunction(
        undefined,
        undefined,
        parameters,
        undefined,
        undefined,
        props.decoder(accessor.array(input), targets[0]!, explore),
      );

    const array = ts.factory.createIdentifier("array");
    const top = ts.factory.createIdentifier("top");

    const statements: ts.Statement[] = [];
    const tupleList: MetadataTuple[] = targets.filter(
      (t) => t instanceof MetadataTuple,
    ) as MetadataTuple[];
    const arrayList: MetadataArray[] = targets.filter(
      (t) => t instanceof MetadataArray,
    ) as MetadataArray[];

    const predicate = (meta: Category): ts.Expression =>
      ts.factory.createAsExpression(
        ts.factory.createArrayLiteralExpression(
          [
            ts.factory.createArrowFunction(
              undefined,
              undefined,
              [
                IdentifierFactory.parameter(
                  "top",
                  meta instanceof MetadataArrayType
                    ? TypeFactory.keyword("any")
                    : ts.factory.createTypeReferenceNode("any[]"),
                ),
              ],
              TypeFactory.keyword("any"),
              undefined,
              props.checker(
                ts.factory.createIdentifier("top"),
                accessor.element(meta),
                {
                  ...explore,
                  tracable: false,
                  postfix: meta instanceof MetadataArrayType ? `"[0]"` : "",
                },
                array,
              ),
            ),
            ts.factory.createArrowFunction(
              undefined,
              undefined,
              [
                IdentifierFactory.parameter(
                  "entire",
                  ts.factory.createTypeReferenceNode("any[]"),
                ),
              ],
              TypeFactory.keyword("any"),
              undefined,
              props.decoder(ts.factory.createIdentifier("entire"), meta, {
                ...explore,
                tracable: true,
              }),
            ),
          ],
          true,
        ),
        ts.factory.createTypeReferenceNode("const"),
      );
    const iterate =
      (init: string) =>
      (from: ts.Expression) =>
      (stmt: ts.Statement): ts.ForOfStatement =>
        ts.factory.createForOfStatement(
          undefined,
          ts.factory.createVariableDeclarationList(
            [ts.factory.createVariableDeclaration(init)],
            ts.NodeFlags.Const,
          ),
          from,
          stmt,
        );

    if (tupleList.length)
      statements.push(
        StatementFactory.constant("array", accessor.array(input)),
        StatementFactory.constant(
          "tuplePredicators",
          ts.factory.createArrayLiteralExpression(
            tupleList.map((x) => predicate(x as Category)),
            true,
          ),
        ),
        iterate("pred")(ts.factory.createIdentifier("tuplePredicators"))(
          ts.factory.createIfStatement(
            ts.factory.createCallExpression(
              ts.factory.createIdentifier("pred[0]"),
              undefined,
              [array],
            ),
            ts.factory.createReturnStatement(
              ts.factory.createCallExpression(
                ts.factory.createIdentifier(`pred[1]`),
                undefined,
                [array],
              ),
            ),
          ),
        ),
      );
    if (arrayList.length) {
      if (tupleList.length === 0)
        statements.push(
          StatementFactory.constant("array", accessor.array(input)),
        );
      statements.push(
        StatementFactory.constant("top", accessor.front(input)),
        ts.factory.createIfStatement(
          ts.factory.createStrictEquality(
            ExpressionFactory.number(0),
            accessor.size(input),
          ),
          ts.isReturnStatement(props.empty)
            ? props.empty
            : ts.factory.createReturnStatement(props.empty),
        ),
        StatementFactory.constant(
          "arrayPredicators",
          ts.factory.createArrayLiteralExpression(
            arrayList.map((x) => predicate(x as Category)),
            true,
          ),
        ),
        StatementFactory.constant(
          "passed",
          ts.factory.createCallExpression(
            IdentifierFactory.access(
              ts.factory.createIdentifier("arrayPredicators"),
            )("filter"),
            undefined,
            [
              ts.factory.createArrowFunction(
                undefined,
                undefined,
                [IdentifierFactory.parameter("pred")],
                undefined,
                undefined,
                ts.factory.createCallExpression(
                  ts.factory.createIdentifier("pred[0]"),
                  undefined,
                  [top],
                ),
              ),
            ],
          ),
        ),
        ts.factory.createIfStatement(
          ts.factory.createStrictEquality(
            ExpressionFactory.number(1),
            ts.factory.createIdentifier("passed.length"),
          ),
          ts.factory.createReturnStatement(
            ts.factory.createCallExpression(
              ts.factory.createElementAccessExpression(
                ts.factory.createNonNullExpression(
                  ts.factory.createIdentifier("passed[0]"),
                ),
                1,
              ),
              undefined,
              [array],
            ),
          ),
          ts.factory.createIfStatement(
            ts.factory.createLessThan(
              ExpressionFactory.number(1),
              ts.factory.createIdentifier("passed.length"),
            ),
            iterate("pred")(ts.factory.createIdentifier("passed"))(
              ts.factory.createIfStatement(
                ts.factory.createCallExpression(
                  IdentifierFactory.access(array)("every"),
                  undefined,
                  [
                    ts.factory.createArrowFunction(
                      undefined,
                      undefined,
                      [
                        IdentifierFactory.parameter(
                          "value",
                          TypeFactory.keyword("any"),
                        ),
                      ],
                      undefined,
                      undefined,
                      ts.factory.createStrictEquality(
                        props.success,
                        ts.factory.createCallExpression(
                          ts.factory.createIdentifier("pred[0]"),
                          undefined,
                          [ts.factory.createIdentifier("value")],
                        ),
                      ),
                    ),
                  ],
                ),
                ts.factory.createReturnStatement(
                  ts.factory.createCallExpression(
                    ts.factory.createIdentifier(`pred[1]`),
                    undefined,
                    [ts.factory.createIdentifier("array")],
                  ),
                ),
              ),
            ),
          ),
        ),
      );
    }
    statements.push(
      props.failure(
        input,
        `(${targets
          .map((t) => accessor.name(t, accessor.element(t)))
          .join(" | ")})`,
        explore,
      ),
    );
    return ts.factory.createArrowFunction(
      undefined,
      undefined,
      parameters,
      undefined,
      undefined,
      ts.factory.createBlock(statements, true),
    );
  };

/**
 * @internal
 */
export namespace check_union_array_like {
  export interface IProps<
    Category extends MetadataArray | MetadataTuple,
    Element,
  > {
    checker(
      front: ts.Expression,
      target: Element,
      explore: FeatureProgrammer.IExplore,
      container: ts.Expression,
    ): ts.Expression;
    decoder: UnionExplorer.Decoder<Category>;
    empty: ts.ReturnStatement | ts.Expression;
    success: ts.Expression;
    failure(
      input: ts.Expression,
      expected: string,
      explore: CheckerProgrammer.IExplore,
    ): ts.Statement;
  }

  export interface IAccessor<
    Origin,
    Category extends MetadataArray | MetadataTuple,
    Element,
  > {
    transform(origin: Origin): Category;
    element(meta: Category): Element;
    name(meta: Category, elem: Element): string;
    front(input: ts.Expression): ts.Expression;
    array(input: ts.Expression): ts.Expression;
    size(input: ts.Expression): ts.Expression;
  }
}