import { ArgMap, CompressedField, CompressedFieldMap, CompressedTypeMap, TypeMap } from "gqlgen-runtime/dist/types";
import {
  GraphQLSchema,
  isEnumType,
  isInputObjectType,
  isInterfaceType,
  isObjectType,
  isScalarType,
  isUnionType,
} from "graphql";
import { excludedTypes } from "../common/excludedTypes";
import { RenderContext } from "../common/RenderContext";
import { objectType } from "./objectType";
import { unionType } from "./unionType";

export function renderTypeMap(schema: GraphQLSchema, ctx: RenderContext) {
  // remove fields key,
  // remove the Type.type and Type.args, replace with [type, args]
  // reverse args.{name}
  // Args type is deduced and added only when the concrete type is different from type name, remove the scalar field and replace with a top level scalars array field.
  const result: TypeMap<string> = {
    scalars: [],
    types: {},
  };

  Object.keys(schema.getTypeMap())
    .filter((t) => !excludedTypes.includes(t))
    .map((t) => schema.getTypeMap()[t])
    .map((t) => {
      if (isObjectType(t) || isInterfaceType(t) || isInputObjectType(t)) result.types[t.name] = objectType(t, ctx);
      else if (isUnionType(t)) result.types[t.name] = unionType(t, ctx);
      else if (isScalarType(t) || isEnumType(t)) {
        result.scalars.push(t.name);
        result.types[t.name] = {};
      }
    });

  // change names of query, mutation on schemas that chose different names (hasura)
  const q = schema.getQueryType();
  if (q?.name && q?.name !== "Query") {
    delete result.types[q.name];
    result.types.Query = objectType(q, ctx);
    // result.Query.name = 'Query'
  }

  const m = schema.getMutationType();
  if (m?.name && m.name !== "Mutation") {
    delete result.types[m.name];
    result.types.Mutation = objectType(m, ctx);
    // result.Mutation.name = 'Mutation'
  }

  const s = schema.getSubscriptionType();
  if (s?.name && s.name !== "Subscription") {
    delete result.types[s.name];
    result.types.Subscription = objectType(s, ctx);
    // result.Subscription.name = 'Subscription'
  }

  ctx.addCodeBlock(JSON.stringify(replaceTypeNamesWithIndexes(result), null, 4));
}

export function replaceTypeNamesWithIndexes(typeMap: TypeMap<string>): CompressedTypeMap<number> {
  const nameToIndex: Record<string, number> = Object.assign(
    {},
    ...Object.keys(typeMap.types).map((k, i) => ({ [k]: i }))
  );
  const scalars = typeMap.scalars.map((x) => nameToIndex[x]);
  const types = Object.assign(
    {},
    ...Object.keys(typeMap.types || {}).map((k) => {
      const type = typeMap.types[k];
      const fieldsMap = type || {};
      // processFields(fields, indexToName)
      const fields = Object.assign(
        {},
        ...Object.keys(fieldsMap).map((f): CompressedFieldMap<number> => {
          const content = fieldsMap[f] as any;
          if (!content) {
            throw new Error("no content in field " + f);
          }
          const [typeName, args] = [content.type, content.args];
          const res: CompressedField<number> = [typeName ? nameToIndex[typeName] : -1];
          if (args) {
            res[1] = Object.assign(
              {},
              ...Object.keys(args || {}).map((k) => {
                const arg = args?.[k];
                if (!arg) {
                  throw new Error("replaceTypeNamesWithIndexes: no arg for " + k);
                }
                return {
                  [k]: [nameToIndex[arg[0]], ...arg.slice(1)],
                } as ArgMap<number>;
              })
            );
          }

          return {
            [f]: res,
          };
        })
      );
      return {
        [k]: {
          ...fields,
        },
      };
    })
  );
  return {
    scalars,
    types,
  };
}