/*
 * Copyright © 2020 Atomist, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import { Java9FileParser, KotlinFileParser } from "@atomist/antlr";
import { File as ProjectFile } from "@atomist/automation-client/lib/project/File";
import { Project } from "@atomist/automation-client/lib/project/Project";
import { fileMatches } from "@atomist/automation-client/lib/tree/ast/astUtils";
import { FileParser } from "@atomist/automation-client/lib/tree/ast/FileParser";
import { FileParserRegistry } from "@atomist/automation-client/lib/tree/ast/FileParserRegistry";
import { logger } from "@atomist/automation-client/lib/util/logger";
import { evaluateScalarValue, PathExpression } from "@atomist/tree-path";
import { KotlinPackage } from "../../java/JavaProjectStructure";
import { JavaSourceFiles, KotlinSourceFiles } from "../../java/javaProjectUtils";
import { packageInfo } from "../../java/query/packageInfo";

/**
 * Path expression for a class name annotated with Spring Boot.
 * Uses Java formal grammar.
 * @type {string}
 */
export const SpringBootAppClassInJava = `//normalClassDeclaration
                                [//annotation[@value='@SpringBootApplication']]
                                /identifier`;

/**
 * Path expression for a class name annotated with Spring Boot.
 * Uses Kotlin formal grammar.
 * @type {string}
 */
export const SpringBootAppClassInKotlin = `//classDeclaration
                                [//annotation[@value='@SpringBootApplication']]
                                //Identifier`;

/**
 * Represents the structure of a Spring Boot project,
 * which can be inferred from its contents. Covers application class
 * and starters.
 */
export class SpringBootProjectStructure {
    /**
     * Infer any number of structures, looking at both Java and Kotlin
     */
    public static async inferFromJavaOrKotlin(p: Project): Promise<SpringBootProjectStructure[]> {
        return (
            await this.inferFromSourceWithJavaLikeImports(p, Java9FileParser, JavaSourceFiles, SpringBootAppClassInJava)
        ).concat(
            await this.inferFromSourceWithJavaLikeImports(
                p,
                KotlinFileParser,
                KotlinSourceFiles,
                SpringBootAppClassInKotlin,
            ),
        );
    }

    private static async inferFromSourceWithJavaLikeImports(
        p: Project,
        parserOrRegistry: FileParser | FileParserRegistry,
        globOptions: string | string[],
        pathExpression: string | PathExpression,
    ): Promise<SpringBootProjectStructure[]> {
        const fileHits = await fileMatches(p, {
            parseWith: parserOrRegistry,
            globPatterns: globOptions,
            pathExpression,
        });
        const matches: SpringBootProjectStructure[] = [];

        for (const fh of fileHits) {
            // It's in the default package if no match found
            const packageName: { name: string } = {
                name:
                    fh.file.extension === "java"
                        ? // TODO using package workaround for Antlr bug
                          ((await packageInfo(p, fh.file.path)) || { fqn: "" }).fqn
                        : evaluateScalarValue(fh.fileNode, KotlinPackage) || "",
            };
            const appClass = fh.matches[0].$value;
            if (packageName && appClass) {
                logger.debug(
                    "Successful Spring Boot inference on %j: packageName '%s', '%s'",
                    p.id,
                    packageName.name,
                    appClass,
                );
                matches.push(new SpringBootProjectStructure(packageName.name, appClass, fh.file));
            } else {
                logger.debug(
                    "Unsuccessful Spring Boot inference on %j: packageName '%j', '%s'",
                    p.id,
                    packageName,
                    appClass,
                );
            }
        }
        return matches;
    }

    /**
     * The stem of the application class. Strip "Application" if present.
     */
    public readonly applicationClassStem: string = this.applicationClass.replace(/Application$/, "");

    /**
     * @param applicationPackage The package with the Spring Boot application class in it.
     * @param applicationClass Name of the application class within the given package
     * @param appClassFile path to the file containing the @SpringBootApplication annotation
     */
    private constructor(
        public readonly applicationPackage: string,
        public readonly applicationClass: string,
        public readonly appClassFile: ProjectFile,
    ) {}
}