<?php
namespace thebigsmileXD\SkyBlock\provider;

use thebigsmileXD\SkyBlock\Plot;
use SQLite3;
use SQLite3Stmt;
use thebigsmileXD\SkyBlock\SkyBlock;

class SQLiteDataProvider extends DataProvider
{
    /** @var SQLite3 */
    private $db;

    /** @var SQLite3Stmt */
    private $sqlGetPlot, $sqlSavePlot, $sqlSavePlotById, $sqlRemovePlot,
            $sqlRemovePlotById, $sqlGetPlotsByOwner, $sqlGetPlotsByOwnerAndLevel,
            $sqlGetExistingXZ;

    public function __construct(SkyBlock $plugin, $cacheSize = 0) {
        parent::__construct($plugin, $cacheSize);

        $this->db = new SQLite3($this->plugin->getDataFolder() . "plots.db");
        $this->db->exec(
            "CREATE TABLE IF NOT EXISTS plots
            (id INTEGER PRIMARY KEY AUTOINCREMENT, level TEXT, X INTEGER, Z INTEGER, name TEXT,
             owner TEXT, helpers TEXT, biome TEXT)"
        );

        $this->sqlGetPlot = $this->db->prepare(
            "SELECT id, name, owner, helpers, biome FROM plots WHERE level = :level AND X = :X AND Z = :Z"
        );
        $this->sqlSavePlot = $this->db->prepare(
            "INSERT OR REPLACE INTO plots (id, level, X, Z, name, owner, helpers, biome) VALUES
            ((select id from plots where level = :level AND X = :X AND Z = :Z),
             :level, :X, :Z, :name, :owner, :helpers, :biome);"
        );
        $this->sqlSavePlotById = $this->db->prepare(
            "UPDATE plots SET name = :name, owner = :owner, helpers = :helpers, biome = :biome WHERE id = :id"
        );
        $this->sqlRemovePlot = $this->db->prepare(
            "DELETE FROM plots WHERE level = :level AND X = :X AND Z = :Z"
        );
        $this->sqlRemovePlotById = $this->db->prepare("DELETE FROM plots WHERE id = :id");
        $this->sqlGetPlotsByOwner = $this->db->prepare("SELECT * FROM plots WHERE owner = :owner");
        $this->sqlGetPlotsByOwnerAndLevel = $this->db->prepare(
            "SELECT * FROM plots WHERE owner = :owner AND level = :level"
        );
        $this->sqlGetExistingXZ = $this->db->prepare(
            "SELECT X, Z FROM plots WHERE (
                level = :level
                AND (
                    (abs(X) == :number AND abs(Z) <= :number) OR
                    (abs(Z) == :number AND abs(X) <= :number)
                )
            )"
        );
    }

    public function close() {
        $this->db->close();
    }

    public function savePlot(Plot $plot) {
        $helpers = implode(",", $plot->helpers);
        if ($plot->id >= 0) {
            $stmt = $this->sqlSavePlotById;
            $stmt->bindValue(":id", $plot->id, SQLITE3_INTEGER);
        } else {
            $stmt = $this->sqlSavePlot;
            $stmt->bindValue(":level", $plot->levelName, SQLITE3_TEXT);
            $stmt->bindValue(":X", $plot->X, SQLITE3_INTEGER);
            $stmt->bindValue(":Z", $plot->Z, SQLITE3_INTEGER);
        }
        $stmt->bindValue(":name", $plot->name, SQLITE3_TEXT);
        $stmt->bindValue(":owner", $plot->owner, SQLITE3_TEXT);
        $stmt->bindValue(":helpers", $helpers, SQLITE3_TEXT);
        $stmt->bindValue(":biome", $plot->biome, SQLITE3_TEXT);
        $stmt->reset();
        $result = $stmt->execute();
        if ($result === false) {
            return false;
        }
        $this->cachePlot($plot);
        return true;
    }

    public function deletePlot(Plot $plot) {
        if ($plot->id >= 0) {
            $stmt = $this->sqlRemovePlotById;
            $stmt->bindValue(":id", $plot->id, SQLITE3_INTEGER);
        } else {
            $stmt = $this->sqlRemovePlot;
            $stmt->bindValue(":level", $plot->levelName, SQLITE3_TEXT);
            $stmt->bindValue(":X", $plot->X, SQLITE3_INTEGER);
            $stmt->bindValue(":Z", $plot->Z, SQLITE3_INTEGER);
        }
        $stmt->reset();
        $result = $stmt->execute();
        if ($result === false) {
            return false;
        }
        $plot = new Plot($plot->levelName, $plot->X, $plot->Z);
        $this->cachePlot($plot);
        return true;
    }

    public function getPlot($levelName, $X, $Z) {
        if ($plot = $this->getPlotFromCache($levelName, $X, $Z)) {
            return $plot;
        }
        $this->sqlGetPlot->bindValue(":level", $levelName, SQLITE3_TEXT);
        $this->sqlGetPlot->bindValue(":X", $X, SQLITE3_INTEGER);
        $this->sqlGetPlot->bindValue(":Z", $Z, SQLITE3_INTEGER);
        $this->sqlGetPlot->reset();
        $result = $this->sqlGetPlot->execute();
        if ($val = $result->fetchArray(SQLITE3_ASSOC)) {
            if ($val["helpers"] === null or $val["helpers"] === "") {
                $helpers = [];
            } else {
                $helpers = explode(",", (string)$val["helpers"]);
            }
            $plot = new Plot($levelName, $X, $Z, (string)$val["name"], (string)$val["owner"],
                $helpers, (string)$val["biome"], (int)$val["id"]);
        } else {
            $plot = new Plot($levelName, $X, $Z);
        }
        $this->cachePlot($plot);
        return $plot;
    }

    public function getPlotsByOwner($owner, $levelName = "") {
        if ($levelName === "") {
            $stmt = $this->sqlGetPlotsByOwner;
        } else {
            $stmt = $this->sqlGetPlotsByOwnerAndLevel;
            $stmt->bindValue(":level", $levelName, SQLITE3_TEXT);
        }
        $stmt->bindValue(":owner", $owner, SQLITE3_TEXT);
        $plots = [];
        $stmt->reset();
        $result = $stmt->execute();
        while ($val = $result->fetchArray(SQLITE3_ASSOC)) {
            $helpers = explode(",", (string)$val["helpers"]);
            $plots[] = new Plot((string)$val["level"], (int)$val["X"], (int)$val["Z"], (string)$val["name"],
                (string)$val["owner"], $helpers, (string)$val["biome"], (int)$val["id"]);
        }
        usort($plots, function ($plot1, $plot2) {
            /** @var Plot $plot1 */
            /** @var Plot $plot2 */
            return strcmp($plot1->levelName, $plot2->levelName);
        });
        return $plots;
    }

    public function getNextFreePlot($levelName, $limitXZ = 20) {
        $this->sqlGetExistingXZ->bindValue(":level", $levelName, SQLITE3_TEXT);
        $i = 0;
        $this->sqlGetExistingXZ->bindParam(":number", $i, SQLITE3_INTEGER);
        for (; $i < $limitXZ; $i++) {
            $this->sqlGetExistingXZ->reset();
            $result = $this->sqlGetExistingXZ->execute();
            $plots = [];
            while ($val = $result->fetchArray(SQLITE3_NUM)) {
                $plots[$val[0]][$val[1]] = true;
            }
            if (count($plots) === max(1, 8 * $i)) {
                continue;
            }

            if ($ret = self::findEmptyPlotSquared(0, $i, $plots)) {
                list($X, $Z) = $ret;
                $plot = new Plot($levelName, $X, $Z);
                $this->cachePlot($plot);
                return $plot;
            }
            for ($a = 1; $a < $i; $a++) {
                if ($ret = self::findEmptyPlotSquared($a, $i, $plots)) {
                    list($X, $Z) = $ret;
                    $plot = new Plot($levelName, $X, $Z);
                    $this->cachePlot($plot);
                    return $plot;
                }
            }
            if ($ret = self::findEmptyPlotSquared($i, $i, $plots)) {
                list($X, $Z) = $ret;
                $plot = new Plot($levelName, $X, $Z);
                $this->cachePlot($plot);
                return $plot;
            }
        }
        return null;
    }

    private static function findEmptyPlotSquared($a, $b, &$plots) {
        if (!isset($plots[$a][$b])) return array($a, $b);
        if (!isset($plots[$b][$a])) return array($b, $a);
        if ($a !== 0) {
            if (!isset($plots[-$a][$b])) return array(-$a, $b);
            if (!isset($plots[$b][-$a])) return array($b, -$a);
        }
        if ($b !== 0) {
            if (!isset($plots[-$b][$a])) return array(-$b, $a);
            if (!isset($plots[$a][-$b])) return array($a, -$b);
        }
        if ($a | $b === 0) {
            if (!isset($plots[-$a][-$b])) return array(-$a, -$b);
            if (!isset($plots[-$b][-$a])) return array(-$b, -$a);
        }
        return null;
    }
}