import * as _ from 'lodash';
import { DocsInfo } from 'ts/pages/documentation/docs_info';
import {
    CustomType,
    CustomTypeChild,
    DocAgnosticFormat,
    DocSection,
    IndexSignature,
    KindString,
    Parameter,
    Property,
    SectionsMap,
    Type,
    TypeDocNode,
    TypeDocType,
    TypeParameter,
    TypescriptMethod,
} from 'ts/types';
import { utils } from 'ts/utils/utils';

export const typeDocUtils = {
    isType(entity: TypeDocNode): boolean {
        return (
            entity.kindString === KindString.Interface ||
            entity.kindString === KindString.Function ||
            entity.kindString === KindString.TypeAlias ||
            entity.kindString === KindString.Variable ||
            entity.kindString === KindString.Enumeration
        );
    },
    isMethod(entity: TypeDocNode): boolean {
        return entity.kindString === KindString.Method;
    },
    isConstructor(entity: TypeDocNode): boolean {
        return entity.kindString === KindString.Constructor;
    },
    isProperty(entity: TypeDocNode): boolean {
        return entity.kindString === KindString.Property;
    },
    isPrivateOrProtectedProperty(propertyName: string): boolean {
        return _.startsWith(propertyName, '_');
    },
    getModuleDefinitionBySectionNameIfExists(
        versionDocObj: TypeDocNode,
        modulePaths: string[],
    ): TypeDocNode | undefined {
        const modules = versionDocObj.children;
        for (const mod of modules) {
            if (_.includes(modulePaths, mod.name)) {
                const moduleWithName = mod;
                return moduleWithName;
            }
        }
        return undefined;
    },
    convertToDocAgnosticFormat(typeDocJson: TypeDocNode, docsInfo: DocsInfo): DocAgnosticFormat {
        const subMenus = _.values(docsInfo.getMenu());
        const orderedSectionNames = _.flatten(subMenus);
        const docAgnosticFormat: DocAgnosticFormat = {};
        _.each(orderedSectionNames, sectionName => {
            const modulePathsIfExists = docsInfo.getModulePathsIfExists(sectionName);
            if (_.isUndefined(modulePathsIfExists)) {
                return; // no-op
            }
            const packageDefinitionIfExists = typeDocUtils.getModuleDefinitionBySectionNameIfExists(
                typeDocJson,
                modulePathsIfExists,
            );
            if (_.isUndefined(packageDefinitionIfExists)) {
                return; // no-op
            }

            // Since the `types.ts` file is the only file that does not export a module/class but
            // instead has each type export itself, we do not need to go down two levels of nesting
            // for it.
            let entities;
            let packageComment = '';
            if (sectionName === docsInfo.sections.types) {
                entities = packageDefinitionIfExists.children;
            } else {
                entities = packageDefinitionIfExists.children[0].children;
                const commentObj = packageDefinitionIfExists.children[0].comment;
                packageComment = !_.isUndefined(commentObj) ? commentObj.shortText : packageComment;
            }

            const docSection = typeDocUtils._convertEntitiesToDocSection(entities, docsInfo, sectionName);
            docSection.comment = packageComment;
            docAgnosticFormat[sectionName] = docSection;
        });
        return docAgnosticFormat;
    },
    _convertEntitiesToDocSection(entities: TypeDocNode[], docsInfo: DocsInfo, sectionName: string) {
        const docSection: DocSection = {
            comment: '',
            constructors: [],
            methods: [],
            properties: [],
            types: [],
        };

        let isConstructor;
        _.each(entities, entity => {
            switch (entity.kindString) {
                case KindString.Constructor:
                    isConstructor = true;
                    const constructor = typeDocUtils._convertMethod(
                        entity,
                        isConstructor,
                        docsInfo.sections,
                        sectionName,
                        docsInfo.subPackageName,
                    );
                    docSection.constructors.push(constructor);
                    break;

                case KindString.Method:
                    if (entity.flags.isPublic) {
                        isConstructor = false;
                        const method = typeDocUtils._convertMethod(
                            entity,
                            isConstructor,
                            docsInfo.sections,
                            sectionName,
                            docsInfo.subPackageName,
                        );
                        docSection.methods.push(method);
                    }
                    break;

                case KindString.Property:
                    if (!typeDocUtils.isPrivateOrProtectedProperty(entity.name)) {
                        const property = typeDocUtils._convertProperty(
                            entity,
                            docsInfo.sections,
                            sectionName,
                            docsInfo.subPackageName,
                        );
                        docSection.properties.push(property);
                    }
                    break;

                case KindString.Interface:
                case KindString.Function:
                case KindString.Variable:
                case KindString.Enumeration:
                case KindString.TypeAlias:
                    if (docsInfo.isPublicType(entity.name)) {
                        const customType = typeDocUtils._convertCustomType(
                            entity,
                            docsInfo.sections,
                            sectionName,
                            docsInfo.subPackageName,
                        );
                        docSection.types.push(customType);
                    }
                    break;

                default:
                    throw utils.spawnSwitchErr('kindString', entity.kindString);
            }
        });
        return docSection;
    },
    _convertCustomType(
        entity: TypeDocNode,
        sections: SectionsMap,
        sectionName: string,
        subPackageName: string,
    ): CustomType {
        const typeIfExists = !_.isUndefined(entity.type)
            ? typeDocUtils._convertType(entity.type, sections, sectionName, subPackageName)
            : undefined;
        const isConstructor = false;
        const methodIfExists = !_.isUndefined(entity.declaration)
            ? typeDocUtils._convertMethod(entity.declaration, isConstructor, sections, sectionName, subPackageName)
            : undefined;
        const indexSignatureIfExists = !_.isUndefined(entity.indexSignature)
            ? typeDocUtils._convertIndexSignature(entity.indexSignature[0], sections, sectionName, subPackageName)
            : undefined;
        const commentIfExists =
            !_.isUndefined(entity.comment) && !_.isUndefined(entity.comment.shortText)
                ? entity.comment.shortText
                : undefined;

        const childrenIfExist = !_.isUndefined(entity.children)
            ? _.map(entity.children, (child: TypeDocNode) => {
                  const childTypeIfExists = !_.isUndefined(child.type)
                      ? typeDocUtils._convertType(child.type, sections, sectionName, subPackageName)
                      : undefined;
                  const c: CustomTypeChild = {
                      name: child.name,
                      type: childTypeIfExists,
                      defaultValue: child.defaultValue,
                  };
                  return c;
              })
            : undefined;

        const customType = {
            name: entity.name,
            kindString: entity.kindString,
            type: typeIfExists,
            method: methodIfExists,
            indexSignature: indexSignatureIfExists,
            defaultValue: entity.defaultValue,
            comment: commentIfExists,
            children: childrenIfExist,
        };
        return customType;
    },
    _convertIndexSignature(
        entity: TypeDocNode,
        sections: SectionsMap,
        sectionName: string,
        subPackageName: string,
    ): IndexSignature {
        const key = entity.parameters[0];
        const indexSignature = {
            keyName: key.name,
            keyType: typeDocUtils._convertType(key.type, sections, sectionName, subPackageName),
            valueName: entity.type.name,
        };
        return indexSignature;
    },
    _convertProperty(
        entity: TypeDocNode,
        sections: SectionsMap,
        sectionName: string,
        subPackageName: string,
    ): Property {
        const source = entity.sources[0];
        const commentIfExists = !_.isUndefined(entity.comment) ? entity.comment.shortText : undefined;
        const property = {
            name: entity.name,
            type: typeDocUtils._convertType(entity.type, sections, sectionName, subPackageName),
            source: {
                fileName: source.fileName,
                line: source.line,
            },
            comment: commentIfExists,
        };
        return property;
    },
    _convertMethod(
        entity: TypeDocNode,
        isConstructor: boolean,
        sections: SectionsMap,
        sectionName: string,
        subPackageName: string,
    ): TypescriptMethod {
        const signature = entity.signatures[0];
        const source = entity.sources[0];
        const hasComment = !_.isUndefined(signature.comment);
        const isStatic = _.isUndefined(entity.flags.isStatic) ? false : entity.flags.isStatic;

        // HACK: we use the fact that the sectionName is the same as the property name at the top-level
        // of the public interface. In the future, we shouldn't use this hack but rather get it from the JSON.
        let callPath;
        if (isConstructor || entity.name === '__type') {
            callPath = '';
        } else if (subPackageName === '0x.js') {
            const topLevelInterface = isStatic ? 'ZeroEx.' : 'zeroEx.';
            callPath =
                !_.isUndefined(sections.zeroEx) && sectionName !== sections.zeroEx
                    ? `${topLevelInterface}${sectionName}.`
                    : topLevelInterface;
        } else {
            callPath = `${sectionName}.`;
        }

        const parameters = _.map(signature.parameters, param => {
            return typeDocUtils._convertParameter(param, sections, sectionName, subPackageName);
        });
        const returnType = typeDocUtils._convertType(signature.type, sections, sectionName, subPackageName);
        const typeParameter = _.isUndefined(signature.typeParameter)
            ? undefined
            : typeDocUtils._convertTypeParameter(signature.typeParameter[0], sections, sectionName, subPackageName);

        const method = {
            isConstructor,
            isStatic,
            name: signature.name,
            comment: hasComment ? signature.comment.shortText : undefined,
            returnComment: hasComment && signature.comment.returns ? signature.comment.returns : undefined,
            source: {
                fileName: source.fileName,
                line: source.line,
            },
            callPath,
            parameters,
            returnType,
            typeParameter,
        };
        return method;
    },
    _convertTypeParameter(
        entity: TypeDocNode,
        sections: SectionsMap,
        sectionName: string,
        subPackageName: string,
    ): TypeParameter {
        const type = typeDocUtils._convertType(entity.type, sections, sectionName, subPackageName);
        const parameter = {
            name: entity.name,
            type,
        };
        return parameter;
    },
    _convertParameter(
        entity: TypeDocNode,
        sections: SectionsMap,
        sectionName: string,
        subPackageName: string,
    ): Parameter {
        let comment = '<No comment>';
        if (entity.comment && entity.comment.shortText) {
            comment = entity.comment.shortText;
        } else if (entity.comment && entity.comment.text) {
            comment = entity.comment.text;
        }

        const isOptional = !_.isUndefined(entity.flags.isOptional) ? entity.flags.isOptional : false;

        const type = typeDocUtils._convertType(entity.type, sections, sectionName, subPackageName);

        const parameter = {
            name: entity.name,
            comment,
            isOptional,
            type,
        };
        return parameter;
    },
    _convertType(entity: TypeDocType, sections: SectionsMap, sectionName: string, subPackageName: string): Type {
        const typeArguments = _.map(entity.typeArguments, typeArgument => {
            return typeDocUtils._convertType(typeArgument, sections, sectionName, subPackageName);
        });
        const types = _.map(entity.types, t => {
            return typeDocUtils._convertType(t, sections, sectionName, subPackageName);
        });

        const isConstructor = false;
        const methodIfExists = !_.isUndefined(entity.declaration)
            ? typeDocUtils._convertMethod(entity.declaration, isConstructor, sections, sectionName, subPackageName)
            : undefined;

        const elementTypeIfExists = !_.isUndefined(entity.elementType)
            ? {
                  name: entity.elementType.name,
                  typeDocType: entity.elementType.type,
              }
            : undefined;

        const type = {
            name: entity.name,
            value: entity.value,
            typeDocType: entity.type,
            typeArguments,
            elementType: elementTypeIfExists,
            types,
            method: methodIfExists,
        };
        return type;
    },
};