// Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.

#pragma once

#include <vespa/vsm/common/docsum.h>
#include <vespa/vsm/common/fieldmodifier.h>
#include <vespa/vsm/vsm/docsumfieldspec.h>
#include <vespa/vsm/vsm/fieldsearchspec.h>
#include <vespa/vsm/vsm/flattendocsumwriter.h>
#include <vespa/vsm/vsm/vsm-adapter.h>
#include <vespa/searchsummary/docsummary/docsumstore.h>
#include <vespa/searchsummary/docsummary/docsum_store_field_value.h>

using search::docsummary::IDocsumStore;

namespace search::docsummary { class IStringFieldConverter; }

namespace vsm {

/**
 * This class implements the IDocsumStore interface such that docsum blobs
 * can be fetched based on local document id. The docsum blobs are generated
 * on the fly when requested.
 **/
class DocsumFilter : public IDocsumStore
{
private:
    using FieldSpecList = std::vector<DocsumFieldSpec>; // list of summary field specs
    using FieldMap = StringFieldIdTMap;

    const IDocSumCache  * _docsumCache;
    DocsumToolsPtr        _tools;
    FieldSpecList         _fields;        // list of summary fields to generate
    FlattenDocsumWriter   _flattenWriter;
    const FieldModifierMap * _snippetModifiers;
    document::FieldValue::UP _cachedValue;
    document::FieldPath _emptyFieldPath;

    const document::FieldValue * getFieldValue(const DocsumFieldSpec::FieldIdentifier & fieldId,
                                               VsmsummaryConfig::Fieldmap::Command command,
                                               const Document & docsum, bool & modified);
    bool write_flatten_field(const DocsumFieldSpec& field_spec, const Document & docsum);
public:
    DocsumFilter(DocsumToolsPtr tools, const IDocSumCache & docsumCache);
    DocsumFilter(const DocsumFilter &) = delete;
    DocsumFilter &operator=(const DocsumFilter &) = delete;
    ~DocsumFilter() override;
    const DocsumTools & getTools() const { return *_tools; }

    /**
     * Initializes this docsum filter using the given field map and field path map.
     * The field map is used to map from field name to field id.
     * The field path map is used to retrieve the field path for each input field.
     *
     * @param fieldMap maps from field name -> field id
     * @param fieldPathMap maps from field id -> field path
     **/
    void init(const FieldMap & fieldMap, const FieldPathMapT & fieldPathMap);

    /**
     * Sets the snippet modifiers to use when writing string fields used as input to snippet generation.
     **/
    void setSnippetModifiers(const FieldModifierMap & modifiers) { _snippetModifiers = &modifiers; }

    void setDocSumStore(const IDocSumCache & docsumCache) { _docsumCache = &docsumCache; }

    // Inherit doc from IDocsumStore
    std::unique_ptr<const search::docsummary::IDocsumStoreDocument> get_document(uint32_t id) override;

    search::docsummary::DocsumStoreFieldValue get_summary_field(uint32_t entry_idx, const Document& doc);
    void insert_summary_field(uint32_t entry_idx, const Document& doc, vespalib::slime::Inserter& inserter, search::docsummary::IStringFieldConverter* converter);
    bool has_flatten_juniper_command(uint32_t entry_idx) const;
    FieldModifier* get_field_modifier(uint32_t entry_idx);
};

}