<?php

namespace Lucent\Query;

use Illuminate\Database\Query\Builder;
use Illuminate\Support\Facades\DB;
use Lucent\Channel\ChannelService;
use Lucent\Edge\Edge;
use Lucent\Primitive\Collection;
use Lucent\Record\InputFormatter;
use Lucent\Record\QueryRecord;
use Lucent\Record\Record;

final  class Query
{

    public Filter $filter;
    public QueryOptions $options;

    public function __construct(
        public readonly ChannelService $channelService,
        public readonly InputFormatter $inputFormatter,
    )
    {
        $this->options = new QueryOptions();
    }

    public function filter(array $filterArguments): Query
    {
        $this->filter = new Filter($filterArguments);
        return $this;
    }


    public function run(): Graph
    {
        $resultsRecords = $this->mainQuery();

        $ids = array_map(function ($rec) {
            return $rec->id;
        }, $resultsRecords);

        $resultChildrenEdgesTargetIds = [];
        $resultChildrenEdges = [];
        if ($this->options->childrenDepth > 0 && !empty($ids)) {
            $resultChildrenEdges = $this->getChildren($ids);
            $resultChildrenEdgesTargetIds = array_map(fn($e) => $e->target, $resultChildrenEdges);
        }
        $resultParentSourceTargetIds = [];
        $resultParentEdges = [];
        if ($this->options->parentsDepth > 0 && !empty($ids)) {
            $resultParentEdges = $this->getParents($ids);
            $resultParentSourceTargetIds = array_map(fn($e) => $e->source, $resultParentEdges);
        }

        $edgesIds = collect($resultParentSourceTargetIds)->merge($resultChildrenEdgesTargetIds)->unique()->values()->toArray();
        $edgeRecords = [];
        if (!empty($edgesIds)) {
            $edgeRecords = DB::table('records')
                ->whereIn("id", $edgesIds)
                ->whereIn("_sys->status", $this->options->status)
                ->get()->toArray();
        }
        $resultsRecordsUnique = collect(array_merge($resultsRecords, $edgeRecords))->unique("id")->values()->toArray();
        $resultEdges = collect(array_merge($resultChildrenEdges, $resultParentEdges))
            ->unique(fn($edge) => $edge->source . $edge->target . $edge->field)
            ->toArray();


        return $this->formatRecords($resultsRecordsUnique, $resultEdges);

    }

    private function formatRecords(array $records, array $edges): Graph
    {
        $queryRecords = collect($records)->map(function ($recordData) {

            $record = Record::fromDB($recordData);
            $record->data = $this->inputFormatter->fill($record->_sys->schema, $record->data);
            $queryRecord = QueryRecord::fromRecord($record);
            $queryRecord->isRoot = data_get($recordData, "isRoot") === true;
            return $queryRecord;
        })->toArray();


        $queryEdges = collect($edges)->map(function ($edgeData) {

            return Edge::fromArray((array)$edgeData);

        })->sortBy("rank")->values()->toArray();


        return new Graph(
            new Collection($queryRecords),
            new Collection($queryEdges),
        );
    }


    public function tree(): Collection
    {
        return $this->run()->tree();
    }


    /**
     * @throws SubqueryNoResultException
     */
    private function parseFilters(Builder $query): Builder
    {
        $filters = $this->filter->run(new Query($this->channelService, $this->inputFormatter));
        $ignoredFilters = [];
        foreach ($filters as $filter) {
            if (in_array($filter["field"], $ignoredFilters)) {
                continue;
            } else if ($filter["operator"] == "in") {
                $query->whereIn($filter["field"], $filter["value"]);
            } else if ($filter["operator"] == "nin") {
                $query->whereNotIn($filter["field"], $filter["value"]);
            } elseif ($filter["operator"] == "eqobject") {

                $object = $filter["value"];
                // unset related filters used here
                $addToIgnored = collect($filters)
                    ->filter(fn($f) => str_starts_with($f["field"], $object))
                    ->values()
                    ->map(fn($f) => $f["field"])
                    ->toArray();

                $ignoredFilters = array_merge($ignoredFilters, $addToIgnored);

                $objectFilters = collect($filters)
                    ->filter(fn($f) => str_starts_with($f["field"], $object))
                    ->values()
                    ->reduce(function ($c, $f) use ($object) {
                        $field = str_replace($object . "->", "", $f["field"]);
                        $c[$field] = $f["value"];
                        return $c;
                    });

                // target result
                // filter[data.previousNames_object]=previousNames&filter[previousNames.name_eq]=alpha&filter[previousNames.id_eqnum]=24
                // $query->whereJsonContains("data->previousNames", [["name" => "alpha", "id" => 24]]);
                // $query->whereJsonContains($filter["field"], [$objectFilters]);
            } else {

                $query->where($filter["field"], $filter["operator"], $filter["value"]);
            }
        }

        $query->whereIn("_sys->status", $this->options->status);
        return $query;
    }

    /**
     * @throws SubqueryNoResultException
     */
    private function mainQuery(): array
    {
        $query = DB::table("records");
        $query = $this->parseFilters($query);
        $query->limit($this->options->limit);
        $query->offset($this->options->skip);
        $query = $this->orderByQuery($query);

        return $query->get()->map(function ($r) {
            $r->isRoot = true;
            return $r;
        })->toArray();
    }

    private
    function getChildren(array $ids): array
    {
        $subquery = DB::table('edges AS g')
            ->select(DB::raw('g.source,g.target,g.rank,"g"."sourceSchema","g"."targetSchema",g.field, 0 as depth '))
            ->whereIn('source', $ids)
            ->limit($this->options->childrenLimit)
            ->unionAll(
                DB::table(DB::raw("edges AS g, search_graph AS sg "))
                    ->selectRaw('g.source,g.target,g.rank,"g"."sourceSchema","g"."targetSchema",g.field,sg.depth + 1 as depth')
                    ->whereRaw("g.source = sg.target")
                    ->where("sg.depth", "<=", $this->options->childrenDepth)
                    ->orderBy("rank")
            );

        return DB::table('search_graph')
            //            ->select(DB::raw("*, 1 as depth "))
            ->withRecursiveExpression('search_graph', $subquery)
            ->get()->toArray();
    }

    private
    function getParents(array $ids): array
    {
        $subquery = DB::table('edges AS g')
            ->select(DB::raw('g.source,g.target,g.rank,"g"."sourceSchema","g"."targetSchema",g.field, 0 as depth '))
            ->limit($this->options->parentsLimit)
            ->whereIn('g.target', $ids)
            ->unionAll(
                DB::table(DB::raw("edges AS g, search_graph AS sg "))
                    ->selectRaw('g.source,g.target,g.rank,"g"."sourceSchema","g"."targetSchema",g.field,sg.depth + 1 as depth')
                    ->whereRaw("g.target = sg.source")
                    ->where("sg.depth", "<=", $this->options->parentsDepth)
                    ->orderBy("rank")
            );

        return DB::table('search_graph')
            //            ->select(DB::raw('sg.source,sg.target,sg.rank,sg."sourceSchema",sg."targetSchema",sg.field,sg.depth'))
            ->withRecursiveExpression('search_graph', $subquery)
            ->get()->toArray();
    }

    /**
     * @throws SubqueryNoResultException
     */
    public
    function runWithCount(): Graph
    {

        $query = DB::table("records");
        $query = $this->parseFilters($query);
        $graph = $this->run();
        $graph->total = $query->count();
        return $graph;
    }


    public
    function limit(int $limit): Query
    {
        $this->options->limit = $limit;
        return $this;
    }

    public
    function skip(int $skip): Query
    {
        $this->options->skip = $skip;
        return $this;
    }

    public function childrenDepth(int $depth): Query
    {
        $this->options->childrenDepth = $depth;
        return $this;
    }

    public function childrenLimit(int $limit): Query
    {
        $this->options->childrenLimit = $limit;
        return $this;
    }

    public function parentsDepth(int $depth): Query
    {
        $this->options->parentsDepth = $depth;
        return $this;
    }

    public function parentsLimit(int $limit): Query
    {
        $this->options->parentsLimit = $limit;
        return $this;
    }


    public function sort(string $sort): Query
    {
        $this->options->sort[] = $sort;
        return $this;
    }

    public function status(array $status): Query
    {
        $this->options->status = $status;
        return $this;
    }

    public
    function orderByQuery(Builder $query): Builder
    {
        foreach ($this->options->sort as $item) {
            $field = str_replace(".", "->", ltrim($item, '-'));
            $dir = str_starts_with($item, '-') ? "desc" : "asc";
            if ($field) {
                $query->orderBy($field, $dir);
            }
        }
        return $query;
    }
}