/*-
 * ~~~~~~licensing~~~~~~
 * atlasmap-entaxy-services
 * ==========
 * Copyright (C) 2020 - 2025 EmDev LLC
 * ==========
 * You may not use this file except in accordance with the License Terms of the Copyright
 * Holder located at: https://entaxy.ru/eula . All copyrights, all intellectual property
 * rights to the Software and any copies are the property of the Copyright Holder. Unless
 * it is explicitly allowed the Copyright Holder, the User is prohibited from using the
 * Software for commercial purposes to provide services to third parties.
 * 
 * The Copyright Holder hereby declares that the Software is provided on an "AS IS".
 * Under no circumstances does the Copyright Holder guarantee or promise that the
 * Software provided by him will be suitable or not suitable for the specific purposes
 * of the User, that the Software will meet all commercial and personal subjective
 * expectations of the User, that the Software will work properly, without technical
 * errors, quickly and uninterruptedly.
 * 
 * Under no circumstances shall the Copyright Holder or its Affiliates is not liable
 * to the User for any direct or indirect losses of the User, his expenses or actual
 * damage, including, downtime; loss of bussines; lost profit; lost earnings; loss
 * or damage to data, property, etc.
 * ~~~~~~/licensing~~~~~~
 */
/*
 * Copyright (C) 2017 Red Hat, 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.
 */
package io.atlasmap.core;

import java.util.Collections;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Optional;
import java.util.concurrent.ConcurrentHashMap;

import io.atlasmap.api.AtlasConstants;
import io.atlasmap.api.AtlasContext;
import io.atlasmap.api.AtlasException;
import io.atlasmap.spi.AtlasFieldReader;
import io.atlasmap.spi.AtlasFieldWriter;
import io.atlasmap.spi.AtlasInternalSession;
import io.atlasmap.spi.AtlasModule;
import io.atlasmap.spi.AtlasPropertyStrategy;
import io.atlasmap.v2.AtlasMapping;
import io.atlasmap.v2.Audit;
import io.atlasmap.v2.AuditStatus;
import io.atlasmap.v2.Audits;
import io.atlasmap.v2.Field;
import io.atlasmap.v2.LookupTable;
import io.atlasmap.v2.Mapping;
import io.atlasmap.v2.Validations;

public class DefaultAtlasSession implements AtlasInternalSession {

    private DefaultAtlasContext atlasContext;
    private final AtlasMapping mapping;
    private Audits audits;
    private Validations validations;
    private Map<String, Object> sourceProperties;
    private Map<String, Object> targetProperties;
    private AtlasPropertyStrategy propertyStrategy;
    private Map<String, Object> sourceMap;
    private Map<String, Object> targetMap;
    private Map<String, AtlasFieldReader> fieldReaderMap;
    private Map<String, AtlasFieldWriter> fieldWriterMap;
    private Head head = new HeadImpl(this);
    private String defaultSourceDocumentId;
    private String defaultTargetDocumentId;

    public DefaultAtlasSession(DefaultAtlasContext context) throws AtlasException {
        this.atlasContext = context;
        initialize();
        if (context.getMapping() == null) {
            this.mapping = null;
            return;
        }
        this.mapping = context.getADMArchiveHandler().cloneMappingDefinition();
    }

    protected void initialize() {
        sourceProperties = new ConcurrentHashMap<String, Object>();
        targetProperties = new ConcurrentHashMap<String, Object>();
        validations = new Validations();
        audits = new Audits();
        sourceMap = new HashMap<>();
        targetMap = new HashMap<>();
        fieldReaderMap = new HashMap<>();
        fieldWriterMap = new HashMap<>();
        head.unset();
    }

    @Override
    public DefaultAtlasContext getAtlasContext() {
        return atlasContext;
    }

    @Override
    public void setAtlasContext(AtlasContext atlasContext) {
        this.atlasContext = (DefaultAtlasContext) atlasContext;
        head.unset();
    }

    @Override
    public AtlasMapping getMapping() {
        return mapping;
    }

    @Override
    public Validations getValidations() {
        return this.validations;
    }

    @Override
    public void setValidations(Validations validations) {
        this.validations = validations;
    }

    @Override
    public Audits getAudits() {
        return this.audits;
    }

    @Override
    public void setAudits(Audits audits) {
        this.audits = audits;
    }

    @Override
    public Object getDefaultSourceDocument() {
        return sourceMap.get(getDefaultSourceDocumentId());
    }

    private String getDefaultSourceDocumentId() {
        if (this.defaultSourceDocumentId == null) {
            Optional<String> found = this.atlasContext.getSourceModules().keySet().stream().filter((key) ->
                !AtlasConstants.CONSTANTS_DOCUMENT_ID.equals(key)
                && !AtlasConstants.PROPERTIES_SOURCE_DOCUMENT_ID.equals(key))
                .findFirst();
            this.defaultSourceDocumentId = found.isPresent() ? found.get() : AtlasConstants.DEFAULT_SOURCE_DOCUMENT_ID;
        }
        return this.defaultSourceDocumentId;
    }

    @Override
    public Object getSourceDocument(String docId) {
        if (docId == null || docId.isEmpty()) {
            return getDefaultSourceDocument();
        }
        if (sourceMap.containsKey(docId)) {
            return sourceMap.get(docId);
        } else if (sourceMap.size() == 1 && sourceMap.containsKey(AtlasConstants.DEFAULT_SOURCE_DOCUMENT_ID)) {
            AtlasUtil.addAudit(this, docId, String.format(
                    "There's no source document with docId='%s', returning default", docId),
                    AuditStatus.WARN, null);
            return getDefaultSourceDocument();
        }
        AtlasUtil.addAudit(this, docId, String.format(
                "There's no source document with docId='%s'", docId), AuditStatus.WARN, null);
        return null;
    }

    @Override
    public boolean hasSourceDocument(String docId) {
        if (docId == null || docId.isEmpty()) {
            return sourceMap.containsKey(AtlasConstants.DEFAULT_SOURCE_DOCUMENT_ID);
        }
        return sourceMap.containsKey(docId);
    }

    @Override
    public Map<String, Object> getSourceDocumentMap() {
        return Collections.unmodifiableMap(sourceMap);
    }

    @Override
    public Object getDefaultTargetDocument() {
        return targetMap.get(getDefaultTargetDocumentId());
    }

    private String getDefaultTargetDocumentId() {
        if (this.defaultTargetDocumentId == null) {
            Optional<String> found = this.atlasContext.getTargetModules().keySet().stream().filter((key) ->
                !AtlasConstants.PROPERTIES_TARGET_DOCUMENT_ID.equals(key))
                .findFirst();
            this.defaultTargetDocumentId = found.isPresent() ? found.get() : AtlasConstants.DEFAULT_TARGET_DOCUMENT_ID;
        }
        return this.defaultTargetDocumentId;
    }

    @Override
    public Object getTargetDocument(String docId) {
        if (docId == null || docId.isEmpty()) {
            return getDefaultTargetDocument();
        }
        if (targetMap.containsKey(docId)) {
            return targetMap.get(docId);
        } else if (targetMap.size() == 1 && targetMap.containsKey(AtlasConstants.DEFAULT_TARGET_DOCUMENT_ID)) {
            AtlasUtil.addAudit(this, docId, String.format(
                    "There's no target document with docId='%s', returning default", docId),
                    AuditStatus.WARN, null);
            return getDefaultTargetDocument();
        }
        AtlasUtil.addAudit(this, docId, String.format(
                "There's no target document with docId='%s'", docId), AuditStatus.WARN, null);
        return null;
    }

    @Override
    public boolean hasTargetDocument(String docId) {
        if (docId == null || docId.isEmpty()) {
            return targetMap.containsKey(AtlasConstants.DEFAULT_TARGET_DOCUMENT_ID);
        }
        return targetMap.containsKey(docId);
    }

    @Override
    public Map<String, Object> getTargetDocumentMap() {
        return Collections.unmodifiableMap(targetMap);
    }

    @Override
    public void setDefaultSourceDocument(Object sourceDoc) {
        this.sourceMap.put(getDefaultSourceDocumentId(), sourceDoc);
    }

    @Override
    public void setSourceDocument(String docId, Object sourceDoc) {
        if (docId == null || docId.isEmpty()) {
            setDefaultSourceDocument(sourceDoc);
        } else {
            // first document is mapped to 'default' as well
            if (this.sourceMap.isEmpty()) {
                setDefaultSourceDocument(sourceDoc);
            }
            this.sourceMap.put(docId, sourceDoc);
        }
    }

    @Override
    public void setDefaultTargetDocument(Object targetDoc) {
        this.targetMap.put(getDefaultTargetDocumentId(), targetDoc);
    }

    @Override
    public void setTargetDocument(String docId, Object targetDoc) {
        if (docId == null || docId.isEmpty()) {
            setDefaultTargetDocument(targetDoc);
        } else {
            // first document is mapped to 'default' as well
            if (this.targetMap.isEmpty()) {
                setDefaultTargetDocument(targetDoc);
            }
            this.targetMap.put(docId, targetDoc);
        }
    }

    @Override
    public AtlasFieldReader getFieldReader(String docId) {
        if (docId == null || docId.isEmpty()) {
            return this.fieldReaderMap.get(AtlasConstants.DEFAULT_SOURCE_DOCUMENT_ID);
        }
        return this.fieldReaderMap.get(docId);
    }

    @Override
    public <T extends AtlasFieldReader> T getFieldReader(String docId, Class<T> clazz) {
        return clazz.cast(getFieldReader(docId));
    }

    @Override
    public void setFieldReader(String docId, AtlasFieldReader reader) {
        if (docId == null || docId.isEmpty()) {
            this.fieldReaderMap.put(AtlasConstants.DEFAULT_SOURCE_DOCUMENT_ID, reader);
        } else {
            this.fieldReaderMap.put(docId, reader);
        }
    }

    @Override
    public AtlasFieldReader removeFieldReader(String docId) {
        if (docId == null || docId.isEmpty()) {
            return this.fieldReaderMap.remove(AtlasConstants.DEFAULT_SOURCE_DOCUMENT_ID);
        }
        return fieldReaderMap.remove(docId);
    }

    @Override
    public AtlasFieldWriter getFieldWriter(String docId) {
        if (docId == null || docId.isEmpty()) {
            return this.fieldWriterMap.get(AtlasConstants.DEFAULT_TARGET_DOCUMENT_ID);
        }
        return this.fieldWriterMap.get(docId);
    }

    @Override
    public <T extends AtlasFieldWriter> T getFieldWriter(String docId, Class<T> clazz) {
        return clazz.cast(getFieldWriter(docId));
    }

    @Override
    public void setFieldWriter(String docId, AtlasFieldWriter writer) {
        if (docId == null || docId.isEmpty()) {
            this.fieldWriterMap.put(AtlasConstants.DEFAULT_TARGET_DOCUMENT_ID, writer);
        }
        this.fieldWriterMap.put(docId, writer);
    }

    @Override
    public AtlasFieldWriter removeFieldWriter(String docId) {
        if (docId == null || docId.isEmpty()) {
            return this.fieldWriterMap.remove(AtlasConstants.DEFAULT_TARGET_DOCUMENT_ID);
        }
        return this.fieldWriterMap.remove(docId);
    }

    @Override
    public Head head() {
        return this.head;
    }

    @Override
    @Deprecated
    public Map<String, Object> getProperties() {
        return getSourceProperties();
    }

    @Override
    public Map<String, Object> getSourceProperties() {
        return this.sourceProperties;
    }

    @Override
    public Map<String, Object> getTargetProperties() {
        return this.targetProperties;
    }

    @Override
    public AtlasPropertyStrategy getAtlasPropertyStrategy() {
        return this.propertyStrategy;
    }
    @Override
    public void setAtlasPropertyStrategy(AtlasPropertyStrategy strategy) {
        this.propertyStrategy = strategy;
    }

    @Override
    public Integer errorCount() {
        int e = 0;
        for (Audit audit : getAudits().getAudit()) {
            if (AuditStatus.ERROR.equals(audit.getStatus())) {
                e++;
            }
        }
        return e;
    }

    @Override
    public boolean hasErrors() {
        for (Audit audit : getAudits().getAudit()) {
            if (AuditStatus.ERROR.equals(audit.getStatus())) {
                return true;
            }
        }
        return false;
    }

    @Override
    public boolean hasWarns() {
        for (Audit audit : getAudits().getAudit()) {
            if (AuditStatus.WARN.equals(audit.getStatus())) {
                return true;
            }
        }
        return false;
    }

    @Override
    public Integer warnCount() {
        int w = 0;
        for (Audit audit : getAudits().getAudit()) {
            if (AuditStatus.WARN.equals(audit.getStatus())) {
                w++;
            }
        }
        return w;
    }

    @Override
    public AtlasModule resolveModule(String docId) {
        // Assuming Document ID is unique across source and target
        AtlasModule answer = this.getAtlasContext().getSourceModules().get(docId);
        if (answer == null) {
            answer = this.getAtlasContext().getTargetModules().get(docId);
        }
        return answer;
    }

    public ConstantModule getConstantModule() {
        return (ConstantModule) this.getAtlasContext().getSourceModules().get(AtlasConstants.CONSTANTS_DOCUMENT_ID);
    }

    public PropertyModule getSourcePropertyModule() {
        return (PropertyModule) this.getAtlasContext().getSourceModules().get(AtlasConstants.PROPERTIES_SOURCE_DOCUMENT_ID);
    }

    public PropertyModule getTargetPropertyModule() {
        return (PropertyModule) this.getAtlasContext().getTargetModules().get(AtlasConstants.PROPERTIES_TARGET_DOCUMENT_ID);
    }

    private class HeadImpl implements Head {
        private DefaultAtlasSession session;
        private Mapping mapping;
        private LookupTable lookupTable;
        private Field sourceField;
        private Field targetField;
        private List<Audit> audits = new LinkedList<Audit>();

        public HeadImpl(DefaultAtlasSession session) {
            this.session = session;
        }

        @Override
        public Mapping getMapping() {
            return this.mapping;
        }

        @Override
        public LookupTable getLookupTable() {
            return this.lookupTable;
        }

        @Override
        public Field getSourceField() {
            return this.sourceField;
        }

        @Override
        public Field getTargetField() {
            return this.targetField;
        }

        @Override
        public Head setMapping(Mapping mapping) {
            this.mapping = mapping;
            return this;
        }

        @Override
        public Head setLookupTable(LookupTable table) {
            this.lookupTable = table;
            return this;
        }

        @Override
        public Head setSourceField(Field sourceField) {
            this.sourceField = sourceField;
            return this;
        }

        @Override
        public Head setTargetField(Field targetField) {
            this.targetField = targetField;
            return this;
        }

        @Override
        public Head unset() {
            this.mapping = null;
            this.lookupTable = null;
            this.sourceField = null;
            this.targetField = null;
            return this;
        }

        @Override
        public boolean hasError() {
            for(Audit audit : audits) {
                if (audit.getStatus() == AuditStatus.ERROR) {
                    return true;
                }
            }
            return false;
        }

        @Override
        public Head addAudit(AuditStatus status, Field field, String message) {
            String docId = field != null ? field.getDocId() : null;
            String docName = AtlasUtil.getDocumentNameById(session, docId);
            String path = field != null ? field.getPath() : null;
            Audit audit = AtlasUtil.createAudit(status, docId, docName, path, null, message);
            this.audits.add(audit);
            return this;
        }

        @Override
        public List<Audit> getAudits() {
            return this.audits;
        }

    }

}
