/*
 * Copyright (c) 2017 Cisco and/or its affiliates.
 *
 * 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.
 */

package io.fd.hc2vpp.docs.scripts

import groovy.text.SimpleTemplateEngine
import io.fd.hc2vpp.docs.api.*
import io.fd.hc2vpp.docs.core.ClassPathTypeIndex
import io.fd.hc2vpp.docs.core.CoverageGenerator
import io.fd.hc2vpp.docs.core.YangTypeLinkIndex
import io.fd.jvpp.acl.future.FutureJVppAcl
import io.fd.jvpp.core.future.FutureJVppCore
import io.fd.jvpp.ioamexport.future.FutureJVppIoamexport
import io.fd.jvpp.ioampot.future.FutureJVppIoampot
import io.fd.jvpp.ioamtrace.future.FutureJVppIoamtrace
import io.fd.jvpp.nat.future.FutureJVppNat
import io.fd.jvpp.nsh.future.FutureJVppNsh

import java.nio.charset.StandardCharsets
import java.nio.file.Files
import java.nio.file.Paths
import java.nio.file.StandardOpenOption
import java.util.stream.Collectors

import static java.util.stream.Collectors.toList

/**
 * Generates VPP api to Yang node index for hc2vpp guice modules listed in api.docs.modules maven property.
 */
class ApiDocsIndexGenerator {

    private static def NL = System.lineSeparator()
    // TODO - check if list of plugin classes can be generated based on list of modules enabled for doc generation
    private static
    def PLUGIN_CLASSES = [FutureJVppCore.class, FutureJVppAcl.class, FutureJVppNat.class, FutureJVppNsh.class,
                          FutureJVppIoamexport.class, FutureJVppIoampot.class, FutureJVppIoamtrace.class]
    private static def TABLE_PART_MARK = "|"

    /**
     * Generate coverage data for all configured coverage.modules and JVpp plugins
     * */
    public static void generate(final project, final log) {
        def loader = this.getClassLoader()

        String moduleNames = project.properties.get("api.docs.modules")
        String projectRoot = project.properties.get("project.root.folder")

        if (moduleNames.trim().isEmpty()) {
            log.info "No modules defined for ${project.name}. Skipping api-docs generation."
            return
        }

        final List<String> moduleNamesList = moduleNames.split(",")

        log.info "Reading module list for ${project.name}"
        def modules = moduleNamesList.stream()
                .map { moduleName -> moduleName.trim() }
                .map { moduleName ->
            log.info "Loading class $moduleName"
            loader.loadClass(moduleName).newInstance()
        }
        .collect(toList())

        String outPath = project.build.outputDirectory

        log.info "Generating yang type generateLink index"
        YangTypeLinkIndex yangTypeIndex = new YangTypeLinkIndex(projectRoot)
        log.info "Classpath type generateLink index"
        ClassPathTypeIndex classPathIndex = new ClassPathTypeIndex(projectRoot)

        log.info "Generating VPP API to YANG mapping"
        PLUGIN_CLASSES.stream()
                .forEach { pluginClass ->
            log.info "Generating mapping for ${pluginClass}"
            final PluginCoverage configCoverage = new CoverageGenerator()
                    .generateConfigCoverage(pluginClass, modules, yangTypeIndex, classPathIndex)
            generateJvppCoverageDoc(configCoverage, outPath, log)

            //TODO operational coverage
        }
    }

    static void generateJvppCoverageDoc(
            final PluginCoverage pluginCoverage, final String outPath, final log) {
        if (!pluginCoverage.hasCoverage()) {
            log.info "Plugin ${pluginCoverage.getPluginName()} does not have coverage data, skipping config docs generation"
            return
        }
        log.info "Generating config api docs for plugin ${pluginCoverage.getPluginName()}"
        def template = this.getClassLoader().getResource("yang_to_jvpp_template")
        def result = new SimpleTemplateEngine()
                .createTemplate(template)
                .make(["pluginName": pluginCoverage.getPluginName(), "tableContent": generateConfigTableContent(pluginCoverage.getCoverage())]).toString()

        log.debug "Docs result for ${pluginCoverage.getPluginName()}$NL$result"

        Paths.get(outPath).toFile().mkdirs()

        def outFileName
        if (pluginCoverage.isConfig()) {
            outFileName = "${normalizePluginName(pluginCoverage.getPluginName())}-yang-config-index.adoc"
        } else {
            outFileName = "${normalizePluginName(pluginCoverage.getPluginName())}-yang-operational-index.adoc"
        }

        def outFilePath = Paths.get(outPath, outFileName)

        Files.write(outFilePath, result.getBytes(StandardCharsets.UTF_8), StandardOpenOption.CREATE)
        log.info "Plugin ${pluginCoverage.getPluginName()} config api docs sucessfully writen to ${outFilePath.toString()}"
    }

    private static String generateConfigTableContent(final Set<CoverageUnit> coverage) {
        coverage.stream().sorted()
                .map { unit ->
            "$NL" +
                    "${vppApiWithLink(unit.vppApi)}" +
                    "${javaApi(unit.javaApi)}" +
                    "${yangTypes(unit.yangTypes)}" +
                    "${supportedOperations(unit.supportedOperations)}"
        }
        .collect(Collectors.joining(NL))
    }

    private static String vppApiWithLink(final VppApiMessage vppApi) {
        "$TABLE_PART_MARK${vppApi.link}[${vppApi.name}]$NL"
    }

    private static String javaApi(final JavaApiMessage javaApi) {
        "$TABLE_PART_MARK${javaApi.name}$NL"
    }

    private static String yangTypes(final List<YangType> yangTypes) {
        "$NL$TABLE_PART_MARK$NL ${yangTypes.stream().map { yangType -> " ${yangType.link}[${yangType.type}]" }.collect(Collectors.joining(NL))}"
    }

    private static String supportedOperations(final Collection<Operation> operations) {
        "$NL$TABLE_PART_MARK${operations.stream().map { reference -> " ${reference.link}[${reference.operation}]" }.collect(Collectors.joining(NL))}"
    }

    private static String normalizePluginName(final String name) {
        name.toLowerCase().replace(" ", "-")
    }
}