<?php

require_once 'Logger.php';
require_once 'Models.php';
require_once 'Utils.php';

class EGGDatabase
{
	const DB_NAME = "";

	/** @var string */
	private $path;

	/* @var PDO */
	private $pdo = null;

	/* @var ILogger */
	private $logger = null;

	/**
	 * @param $path string
	 * @param $log ILogger
	 */
	public function __construct(string $path, ILogger $log)
	{
		$this->path   = $path;
		$this->logger = $log;
	}

	public function open()
	{
		$exists = file_exists($this->path);

		if (!$exists) $this->logger->proclog("No database file found. Creating new at '" . $this->path . "'");

		$dsn = "sqlite:" . $this->path;
		$opt =
		[
			PDO::ATTR_ERRMODE            => PDO::ERRMODE_EXCEPTION,
			PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
		];

		$this->pdo = new PDO($dsn, null, null, $opt);

		if(!$exists) $this->init();
	}

	public function openReadOnly()
	{
		$this->open();
	}

	public function beginTransaction()
	{
		$this->pdo->beginTransaction();
	}

	public function commitTransaction()
	{
		$this->pdo->commit();
	}

	public function abortTransactionIfExists()
	{
		if ($this->pdo !== null && $this->pdo->inTransaction()) $this->pdo->rollBack();
	}

	private function init()
	{
		$this->logger->proclog("Initialize new database '" . $this->path . "'");

		$this->query_from_file(__DIR__."/db_init.sql");
	}

	public function close()
	{
		$this->pdo = null; // https://stackoverflow.com/questions/18277233
	}

	/** @param $path string */
	public function query_from_file(string $path)
	{
		$sql = file_get_contents($path);

		$cmds = explode("/*----SPLIT----*/", $sql);

		foreach ($cmds as $cmd) $this->pdo->exec($cmd);
	}

	public function sql_query_assoc(string $query)
	{
		$r = $this->pdo->query($query)->fetchAll(PDO::FETCH_ASSOC);

		return $r;
	}

	public function sql_query_assoc_prep(string $query, array $params)
	{
		$stmt = $this->pdo->prepare($query);

		foreach ($params as $p)
		{
			if (strpos($query, $p[0]) !== FALSE) $stmt->bindValue($p[0], $p[1], $p[2]);
		}

		$stmt->execute();

		return $stmt->fetchAll(PDO::FETCH_ASSOC);
	}

	public function sql_query_assoc_pre_prep(PDOStatement $stmt, array $params)
	{
		$stmt->closeCursor();

		foreach ($params as $p)
		{
			if (strpos($stmt->queryString, $p[0]) !== FALSE) $stmt->bindValue($p[0], $p[1], $p[2]);
		}

		$stmt->execute();

		return $stmt->fetchAll(PDO::FETCH_ASSOC);
	}

	public function sql_exec_prep(string $query, array $params)
	{
		$stmt = $this->pdo->prepare($query);

		foreach ($params as $p)
		{
			if (strpos($query, $p[0]) !== FALSE) $stmt->bindValue($p[0], $p[1], $p[2]);
		}

		$stmt->execute();

		return $stmt->rowCount();
	}

	public function sql_exec_pre_prep(PDOStatement $stmt, array $params)
	{
		$stmt->closeCursor();

		foreach ($params as $p)
		{
			if (str_contains($stmt->queryString, $p[0])) $stmt->bindValue($p[0], $p[1], $p[2]);
		}

		$stmt->execute();

		return $stmt->rowCount();
	}

	/**
	 * @param string $url
	 * @param string $name
	 * @param string $source
	 * @return Repository
	 * @throws Exception
	 */
	public function getOrCreateRepository(string $url, string $name, string $source)
	{
		$repo = $this->sql_query_assoc_prep("SELECT * FROM repositories WHERE url = :url",
			[
				[":url", $url, PDO::PARAM_STR],
			]);

		if (count($repo) === 0)
		{
			$this->sql_exec_prep("INSERT INTO repositories (url, name, source, last_update, last_change) VALUES (:url, :nam, :src, :lu, :lc)",
				[
					[":url", $url,            PDO::PARAM_STR],
					[":nam", $name,           PDO::PARAM_STR],
					[":src", $source,         PDO::PARAM_STR],
					[":lu",  Utils::sqlnow(), PDO::PARAM_STR],
					[":lc",  Utils::sqlnow(), PDO::PARAM_STR],
				]);

			$repo = $this->sql_query_assoc_prep("SELECT * FROM repositories WHERE url = :url",
				[
					[":url", $url, PDO::PARAM_STR],
				]);

			if (count($repo) === 0) throw new EGGException("No repo after insert [" . $source . "|" . $name . "]");

			$this->logger->proclog("Inserted (new) repository [" . $source . "|" . $name . "] into database");
		}

		$r = new Repository();
		$r->ID         = $repo[0]['id'];
		$r->URL        = $repo[0]['url'];
		$r->Name       = $repo[0]['name'];
		$r->Source     = $repo[0]['source'];
		$r->LastUpdate = $repo[0]['last_update'];
		$r->LastChange = $repo[0]['last_change'];
		return $r;
	}

	/**
	 * @param string $source
	 * @param Repository $repo
	 * @param string $name
	 * @return Branch
	 * @throws Exception
	 */
	public function getOrCreateBranch(string $source, Repository $repo, string $name)
	{
		$branch = $this->sql_query_assoc_prep("SELECT * FROM branches WHERE repo_id = :rid AND name = :nam",
			[
				[":rid", $repo->ID, PDO::PARAM_INT],
				[":nam", $name,     PDO::PARAM_STR],
			]);

		if (count($branch) === 0)
		{
			$this->sql_exec_prep("INSERT INTO branches (repo_id, name, head, last_update, last_change) VALUES (:rid, :nam, :sha, :lu, :lc)",
				[
					[":rid", $repo->ID,       PDO::PARAM_INT],
					[":nam", $name,           PDO::PARAM_STR],
					[":sha", null,            PDO::PARAM_STR],
					[":lu",  Utils::sqlnow(), PDO::PARAM_STR],
					[":lc",  Utils::sqlnow(), PDO::PARAM_STR],
				]);

			$branch = $this->sql_query_assoc_prep("SELECT * FROM branches WHERE repo_id = :rid AND name = :nam",
				[
					[":rid", $repo->ID, PDO::PARAM_INT],
					[":nam", $name,     PDO::PARAM_STR],
				]);

			if (count($branch) === 0) throw new EGGException("No branch after insert [" . $source . "|" . $repo->Name  . "|" . $name . "]");

			$this->logger->proclog("Inserted (new) branch [" . $source . "|" . $repo->Name  . "|" . $name . "] into database");
		}

		$r = new Branch();
		$r->ID         = $branch[0]['id'];
		$r->Name       = $branch[0]['name'];
		$r->Repo       = $repo;
		$r->Head       = $branch[0]['head'];
		$r->LastUpdate = $branch[0]['last_update'];
		$r->LastChange = $branch[0]['last_change'];
		return $r;
	}

	/**
	 * @param string $source
	 * @param Repository $repo
	 * @param Branch $branch
	 * @param Commit[] $commits
	 */
	public function insertNewCommits(string $source, Repository $repo, Branch $branch, array $commits) {
		$this->logger->proclog("Inserting " . count($commits) . " (new) commits into [" . $source . "|" . $repo->Name  . "|" . $branch->Name . "]");


		$stmtAddCommit = $this->pdo->prepare("INSERT INTO commits ([branch_id], [hash]) VALUES (:brid, :sha)");
		$stmtAddMD = $this->pdo->prepare("INSERT OR IGNORE INTO metadata ([hash], [author_name], [author_email], [committer_name], [committer_email], [message], [date], [parent_commits]) VALUES (:sha, :an, :am, :cn, :cm, :msg, :dat, :prt)");
		$stmtGetID = $this->pdo->prepare("SELECT id FROM commits WHERE [branch_id] = :brid AND [Hash] = :sha");

		foreach ($commits as $commit)
		{
			$jparents = "[]";
			if (count($commit->Parents) > 0) $jparents = '["'.implode('","', $commit->Parents).'"]';

			$this->sql_exec_pre_prep($stmtAddCommit,
				[
					[":brid", $branch->ID,             PDO::PARAM_INT],
					[":sha",  $commit->Hash,           PDO::PARAM_STR],
				]);

			$this->sql_exec_pre_prep($stmtAddMD,
				[
					[":sha",  $commit->Hash,           PDO::PARAM_STR],
					[":an",   $commit->AuthorName,     PDO::PARAM_STR],
					[":am",   $commit->AuthorEmail,    PDO::PARAM_STR],
					[":cn",   $commit->CommitterName,  PDO::PARAM_STR],
					[":cm",   $commit->CommitterEmail, PDO::PARAM_STR],
					[":msg",  $commit->Message,        PDO::PARAM_STR],
					[":dat",  $commit->Date,           PDO::PARAM_STR],
					[":prt",  $jparents,               PDO::PARAM_STR],
				]);

			$dbid = $this->sql_query_assoc_pre_prep($stmtGetID,
				[
					[":brid", $branch->ID,             PDO::PARAM_INT],
					[":sha",  $commit->Hash,           PDO::PARAM_STR],
				]);

			$commit->ID = $dbid[0]['id'];
		}
	}

	/**
	 * @param Branch $branch
	 * @param string $head
	 */
	public function setBranchHead(Branch $branch, string $head) {
		$this->logger->proclog("Set HEAD of branch [" . $branch->Repo->Source . "|" . $branch->Repo->Name  . "|" . $branch->Name . "] to {".substr($head, 0, 8)."}");

		$this->sql_exec_prep("UPDATE branches SET head = :head WHERE id = :id",
			[
				[":id",   $branch->ID, PDO::PARAM_INT],
				[":head", $head,       PDO::PARAM_STR],
			]);

		$branch->Head = $head;
	}

	public function setUpdateDateOnRepository(Repository $repo) {
		$now = Utils::sqlnow();
		$this->sql_exec_prep("UPDATE repositories SET last_update = :now WHERE id = :id",
			[
				[":id",  $repo->ID, PDO::PARAM_INT],
				[":now", $now,      PDO::PARAM_STR],
			]);
		$repo->LastUpdate = $now;
	}

	public function setChangeDateOnRepository(Repository $repo) {
		$now = Utils::sqlnow();
		$this->sql_exec_prep("UPDATE repositories SET last_change = :now WHERE id = :id",
			[
				[":id",  $repo->ID, PDO::PARAM_INT],
				[":now", $now,      PDO::PARAM_STR],
			]);
		$repo->LastChange = $now;
	}

	public function setUpdateDateOnBranch(Branch $branch) {
		$now = Utils::sqlnow();
		$this->sql_exec_prep("UPDATE branches SET last_update = :now WHERE id = :id",
			[
				[":id",  $branch->ID, PDO::PARAM_INT],
				[":now", $now,        PDO::PARAM_STR],
			]);
		$branch->LastUpdate = $now;
	}

	public function setChangeDateOnBranch(Branch $branch) {
		$now = Utils::sqlnow();
		$this->sql_exec_prep("UPDATE branches SET last_change = :now WHERE id = :id",
			[
				[":id",  $branch->ID, PDO::PARAM_INT],
				[":now", $now,        PDO::PARAM_STR],
			]);
		$branch->LastChange = $now;
	}

	/**
	 * @param string $source
	 * @param Repository $repo
	 * @param Branch[] $branches
	 */
	public function deleteOtherBranches(string $source, Repository $repo, array $branches)
	{
		$db = $this->sql_query_assoc_prep("SELECT id, repo_id, name FROM branches WHERE repo_id = :rid",
			[
				[":rid", $repo->ID, PDO::PARAM_STR]
			]);

		foreach ($db as $dbname)
		{
			$exist = false;
			foreach ($branches as $brnch) if ($brnch->ID === $dbname['id']) $exist = true;

			if (!$exist) $this->deleteBranchRecursive($source, $repo->Name, $dbname['name'], $dbname['id']);
		}
	}

	/**
	 * @param string $source
	 * @param Repository[] $repos
	 */
	public function deleteOtherRepositories(string $source, array $repos)
	{
		$db = $this->sql_query_assoc_prep("SELECT id, url, name FROM repositories WHERE source = :src",
			[
				[":src", $source, PDO::PARAM_STR]
			]);

		foreach ($db as $dbname)
		{
			$exist = false;
			foreach ($repos as $rep) if ($rep->ID === $dbname['id']) $exist = true;

			if (!$exist) $this->deleteRepositoryRecursive($source, $dbname['name'], $dbname['id']);
		}
	}

	public function deleteDanglingCommitdata(string $name)
	{
		$hashes = $this->sql_query_assoc_prep("SELECT metadata.hash AS mdh FROM metadata LEFT JOIN commits ON metadata.hash = commits.hash WHERE commits.hash IS NULL", []);

		if (count($hashes) === 0) return;

		$this->logger->proclog("Deleting ".count($hashes)." dangling commits [" . $name . "] from database (no longer linked)");

		$this->beginTransaction();
		foreach ($hashes as $hash) {
			$this->sql_query_assoc_prep("DELETE FROM metadata WHERE hash = :hash", [ [":hash", $hash['mdh'], PDO::PARAM_STR] ]);
		}
		$this->commitTransaction();

		$this->logger->proclog("Succesfully deleted ".count($hashes)." dangling commits");
	}

	/**
	 * @param string $source
	 * @param string $name
	 * @param int $id
	 */
	private function deleteRepositoryRecursive(string $source, string $name, int $id)
	{
		$this->logger->proclog("Delete repository [".$source."|" . $name . "] from database (no longer exists)");

		$branches = $this->sql_query_assoc_prep("SELECT id FROM branches WHERE repo_id = :rid", [ [":rid", $id, PDO::PARAM_INT] ]);

		$this->sql_exec_prep("DELETE FROM repositories WHERE id = :id", [[":id", $id, PDO::PARAM_INT]]);
		$this->sql_exec_prep("DELETE FROM branches WHERE repo_id = :rid", [[":rid", $id, PDO::PARAM_INT]]);
		foreach ($branches as $branch) $this->sql_exec_prep("DELETE FROM commits WHERE branch_id = :bid", [[":bid", $branch["id"], PDO::PARAM_INT]]);
	}

	/**
	 * @param string $source
	 * @param string $reponame
	 * @param string $name
	 * @param int $id
	 */
	private function deleteBranchRecursive(string $source, string $reponame, string $name, int $id)
	{
		$this->logger->proclog("Delete branch [" . $source . "|" . $reponame . "|" . $name . "] from database (no longer exists)");

		$this->sql_exec_prep("DELETE FROM branches WHERE id = :bid",       [[":bid", $id, PDO::PARAM_INT]]);
		$this->sql_exec_prep("DELETE FROM commits WHERE branch_id = :bid", [[":bid", $id, PDO::PARAM_INT]]);
	}

	/**
	 * @param Branch $branch
	 */
	public function deleteAllCommits(Branch $branch) {
		$this->sql_exec_prep("DELETE FROM commits WHERE branch_id = :bid", [[":bid", $branch->ID, PDO::PARAM_INT]]);
	}

	public function deleteOldSources(array $sources)
	{
		$dbsources = $this->sql_query_assoc_prep("SELECT source FROM repositories GROUP BY source", []);

		foreach ($dbsources as $dbsrc)
		{
			$exist = false;
			foreach ($sources as $src) if ($src === $dbsrc['source']) $exist=true;

			if (!$exist)
			{
				$this->logger->proclog("Delete source [" . $dbsrc['source'] . "] from database (no longer exists)");
				$repos = $this->sql_query_assoc_prep("SELECT source,name,id FROM repositories WHERE source = :src", [ [":src", $dbsrc['source'], PDO::PARAM_STR] ]);

				foreach ($repos as $r) $this->deleteRepositoryRecursive($r['source'], $r['name'], $r['id']);
			}
		}
	}

	/**
	 * @param int $year
	 * @param string[] $identities
	 * @return array
	 */
	public function getCommitCountOfYearByDate(int $year, array $identities): array
	{
		$sql = file_get_contents(__DIR__ . "/db_queryyear.sql");

		$cond = "(1=0)";
		$prep =
			[
				[":year", "".$year, PDO::PARAM_STR]
			];
		$i=0;
		foreach ($identities as $ident)
		{
			$cond .= " OR (mail1 = :_".$i."_)";
			$prep []= [":_".$i."_", $ident, PDO::PARAM_STR];
			$i++;
			$cond .= " OR (mail2 = :_".$i."_)";
			$prep []= [":_".$i."_", $ident, PDO::PARAM_STR];
			$i++;
		}

		$sql = str_replace("/*{INDETITY_COND}*/", $cond, $sql);

		$rows = $this->sql_query_assoc_prep($sql, $prep);

		$r = [];
		foreach ($rows as $row) $r[$row['commitdate']] = $row['count'];

		return $r;
	}

	/**
	 * @return int[]
	 */
	public function getAllYears(): array
	{
		$rows = $this->sql_query_assoc("SELECT d FROM (SELECT cast(strftime('%Y', metadata.date) as decimal) AS d FROM commits LEFT JOIN metadata ON commits.hash = metadata.hash) GROUP BY d ORDER BY d");
		$r = [];
		foreach ($rows as $row) $r []= $row['d'];
		return $r;
	}

	/**
	 * @return Commit[]
	 */
	public function getCommitsForBranch(Branch $branch): array
	{
		$rows = $this->sql_query_assoc_prep("SELECT metadata.*, commits.id AS commitid FROM commits LEFT JOIN metadata ON metadata.hash = commits.hash WHERE commits.branch_id = :bid",
			[
				[":bid", $branch->ID, PDO::PARAM_INT]
			]);

		$r = [];
		foreach ($rows as $row)
		{
			$c = new Commit();
			$c->ID             = $row['commitid'];
			$c->Branch         = $branch;
			$c->Hash           = $row['hash'];
			$c->AuthorName     = $row['author_name'];
			$c->AuthorEmail    = $row['author_email'];
			$c->CommitterName  = $row['committer_name'];
			$c->CommitterEmail = $row['committer_email'];
			$c->Message        = $row['message'];
			$c->Date           = $row['date'];
			$c->Parents        = json_decode($row['parent_commits']);
			$r []= $c;
		}
		return $r;
	}

	/**
	 * @return Commit[]
	 */
	public function getCommitsForRepo(Repository $repo, Branch $branchValue): array
	{
		$rows = $this->sql_query_assoc_prep("SELECT DISTINCT metadata.* FROM branches INNER JOIN commits ON branches.id = commits.branch_id LEFT JOIN metadata ON metadata.hash = commits.hash WHERE branches.repo_id = :rid",
			[
				[":rid", $repo->ID, PDO::PARAM_INT]
			]);

		$r = [];
		foreach ($rows as $row)
		{
			$c = new Commit();
			$c->Branch         = $branchValue;
			$c->Hash           = $row['hash'];
			$c->AuthorName     = $row['author_name'];
			$c->AuthorEmail    = $row['author_email'];
			$c->CommitterName  = $row['committer_name'];
			$c->CommitterEmail = $row['committer_email'];
			$c->Message        = $row['message'];
			$c->Date           = $row['date'];
			$c->Parents        = json_decode($row['parent_commits']);
			$r []= $c;
		}
		return $r;
	}

	public function checkDatabase(): array{

		$result = [];

		// ======== [1] invalid json in parent_commits ==========
		{
			$errors = $this->sql_query_assoc_prep("SELECT * FROM metadata WHERE NOT json_valid(parent_commits)", []);

			foreach ($errors as $e) {
				$result []= "Found commit-metadata entry {".$e['hash']."} with invalid json in 'parent_commits'";
			}
		}

		// ======== [2] metadata with missing parent ==========
		{
			$errors = $this->sql_query_assoc_prep("
SELECT md1.*, md2.hash as check_hash FROM (
	
	SELECT 
		md1.*, mdp.value AS parent 
	FROM 
		metadata AS md1, json_each(md1.parent_commits) AS mdp 

) AS md1
	
LEFT JOIN metadata AS md2 ON md1.parent = md2.hash

WHERE md1.parent != '' AND check_hash IS NULL", []);

			foreach ($errors as $e) {
				$result []= "Found commit-metadata entry {".$e['hash']."} with an reference to a not-existing parent '".$e['parent']."'";
			}
		}

		// ======== [3] repositories without branches ==========
		{
			$errors = $this->sql_query_assoc_prep("SELECT repositories.*, (SELECT COUNT(*) FROM branches WHERE repositories.id = branches.repo_id) AS branch_count FROM repositories WHERE branch_count = 0", []);

			foreach ($errors as $e) {
				$result []= "Found repository [".$e['id']."]'".$e['name']."' without any branches";
			}
		}


		// ======== [4] branches without commits ==========
		{
			$errors = $this->sql_query_assoc_prep("SELECT branches.*, (SELECT COUNT(*) FROM commits WHERE branches.id = commits.branch_id) AS commit_count FROM branches WHERE commit_count = 0", []);

			foreach ($errors as $e) {
				$result []= "Found branch [".$e['id']."]'".$e['name']."' without any commits";
			}
		}

		// ======== [5] commits with missing metadata ==========
		{
			$errors = $this->sql_query_assoc_prep("SELECT commits.*, metadata.hash AS mdh FROM commits LEFT JOIN metadata ON commits.hash = metadata.hash WHERE mdh IS NULL", []);

			foreach ($errors as $e) {
				$result []= "Missing metadata for commit ".$e['id']." | {".$e['hash']."}";
			}
		}

		// ======== [6] metadata with missing commits ==========
		{
			$errors = $this->sql_query_assoc_prep("SELECT metadata.*, commits.hash AS ch FROM metadata LEFT JOIN commits ON commits.hash = metadata.hash WHERE ch IS NULL", []);

			foreach ($errors as $e) {
				$result []= "Missing commit for metadata entry {".$e['hash']."}";
			}
		}

		// ======== [7] missing branch-head in commits ==========
		{
			$errors = $this->sql_query_assoc_prep("SELECT branches.*, commits.id AS cid FROM branches LEFT JOIN commits ON branches.head = commits.hash WHERE cid IS NULL", []);

			foreach ($errors as $e) {
				$result []= "Missing head-commit {".$e['head']."} for branch ".$e['id'].": '".$e['name']."'";
			}
		}

		return $result;
	}
}