<?php
$db = new SQLite3(DB_LOCATION, SQLITE3_OPEN_READWRITE);
$db->exec("pragma journal_mode=wal2;");
$db->exec("pragma synchronous=normal;");

/* TABLE OF CONTENTS ==========
I. Cleanup
II. Cache Requests
III. Cache Updates
IV. User Ban/Suspension Lookup
V. User Ban/Susppension Management
VI. Create Tables If Needed
*/

/* I. CLEANUP */

function deleteExpired(string $table): void {
  global $db;
  $db->exec('delete from '.$table.' where expires <= '.strtotime('now').';');
}

/* II. CACHE REQUESTS */

function requestUserCache(string $value, string $field = "handle"): object|bool {
  global $db;
  findOrCreateUserTable();
  deleteExpired('user_cache');
  $result = $db->query("select * from user_cache where ".$field."='".$value."' limit 1;");
  $arr = $result->fetchArray(SQLITE3_ASSOC);
  if (!is_array($arr) || count($arr) === 0) return false;
  $arr['displayName'] = $arr['display_name'];
  $arr['pinnedPost'] = $arr['pinned_post'];
  unset($arr['display_name']);
  unset($arr['pinned_post']);
  return (object) $arr;
}

function requestMinidocCache(string $value): object|bool {
  global $db;
  findOrCreateMinidocTable();
  deleteExpired('minidoc_cache');
  $result = $db->query("select * from minidoc_cache where did='".$value."' limit 1;");
  $arr = $result->fetchArray(SQLITE3_ASSOC);
  if (!is_array($arr) || count($arr) === 0) return false;
  return (object) $arr;
}

function requestPlcCache(string $did): object|bool {
  global $db;
  findOrCreatePlcTable();
  deleteExpired('plc_cache');
  $result = $db->query("select * from plc_cache where did='".$did."' limit 1;");
  $arr = $result->fetchArray(SQLITE3_ASSOC);
  if (is_array($arr) && count($arr) > 0) return (object) $arr;
  return false;
}

function requestFeedCache(string $atUri): object|bool {
  global $db;
  findOrCreateFeedsTable();
  deleteExpired('feed_cache');
  $result = $db->query("select * from feed_cache where at_uri='".$atUri."' limit 1;");
  $arr = $result->fetchArray(SQLITE3_ASSOC);
  if (is_array($arr) && count($arr) > 0) return (object) $arr;
  return false;
}

function requestPostCache(string $rkey): object|bool {
  global $db;
  findOrCreatePostTable();
  deleteExpired('post_cache');
  $result = $db->query("select * from post_cache where rkey='".$rkey."' limit 1;");
  $arr = $result->fetchArray(SQLITE3_ASSOC);
  if (is_array($arr) && count($arr) > 0) {
    $arr['embedType'] = $arr['embed_type'];
    $arr['embeds'] = $arr['embed_data'];
    $arr['createdAt'] = $arr['created_at'];
    unset($arr['embed_type']);
    unset($arr['embed_data']);
    unset($arr['created_at']);
    return (object) $arr;
  }
  return false;
}

/* III. CACHE UPDATES */

function updateUserCache(string $handle, string $did, ?string $displayName, string $pds, ?string $avatar, ?string $banner, ?string $description, ?string $pinned): void {
  global $db;
  findOrCreateUserTable();
  $newExpiration = strtotime('now') + 60*60;
  if (requestUserCache($did, 'did')) {
    $db->exec("update user_cache set handle='".$handle."', display_name='".SQLite3::escapeString($displayName)."', pds='".$pds."', avatar='".$avatar."', banner='".$banner."', description='".SQLite3::escapeString($description)."', pinned_post='".$pinned."', expires='".$newExpiration."' where did='".$did."';");
  } else {
    $db->exec("insert into user_cache (handle, did, display_name, pds, avatar, banner, description, pinned_post, expires) values ('".$handle."', '".$did."', '".SQLite3::escapeString($displayName)."', '".$pds."', '".$avatar."', '".$banner."', '".SQLite3::escapeString($description)."', '".$pinned."', '".$newExpiration."');");
  }
}

function updateMinidocCache(string $handle, string $did, string $pds, string $signingKey): void {
  global $db;
  findOrCreateMinidocTable();
  $newExpiration = strtotime('now') + 60*60*48;
  if (requestMinidocCache($handle)) {
    $db->exec("update minidoc_cache set handle='".$handle."', did='".$did."', pds='".$pds."', signing_key='".$signingKey."', expires=".$newExpiration.";");
  } else {
    $db->exec("insert into minidoc_cache (handle, did, pds, signing_key, expires) values ('".$handle."', '".$did."', '".$pds."', '".$signingKey."', ".$newExpiration.");");
  }
}

function updatePlcCache(string $did, string $plcdoc): void {
  global $db;
  findOrcreatePlcTable();
  $newExpiration = strtotime('now') + 60*60*48;
  if (requestPlcCache($did)) {
    $db->exec("update plc_cache set plcdoc='".$plcdoc."', expires='".$newExpiration."' where did='".$did."';");
  } else {
    $db->exec("insert into plc_cache (did, plcdoc, expires) values ('".$did."', '".$plcdoc."', '".$newExpiration."');");
  }
}

function updateFeedCache(string $atUri, string $title, ?string $description, ?string $avatar, string $creator_did) {
  global $db;
  findOrCreateFeedsTable();
  $newExpiration = strtotime('now') + 60*60*4;
  if (requestFeedCache($atUri)) {
    $db->exec("update feed_cache set title='".SQLite3::escapeString($title)."', description='".SQLite3::escapeString($description)."', avatar='".$avatar."', creator_did='".$creator_did."', expires='".$newExpiration."' where at_uri='".$atUri."';");
  } else {
    $db->exec("insert into feed_cache (at_uri, title, description, avatar, creator_did, expires) values ('".$atUri."', '".SQLite3::escapeString($title)."', '".SQLite3::escapeString($description)."', '".$avatar."', '".$creator_did."', '".$newExpiration."');");
  }
}

function updatePostCache(string $rkey, string $did, string $text, ?string $embedType, ?string $embedData, string $createdAt): void {
  global $db;
  findOrCreatePostTable();
  $newExpiration = strtotime('now') + 60*60*48;
  if (requestPostCache($rkey)) {
    $db->exec("update post_cache set text='".SQLite3::escapeString($text)."', embed_type='".$embedType."', embed_data='".SQLite3::escapeString($embedData)."', expires='".$newExpiration."', created_at='".$createdAt."' where rkey='".$rkey."';");
  } else {
    $db->exec("insert into post_cache (rkey, did, text, embed_type, embed_data, created_at, expires) values ('".$rkey."', '".$did."', '".SQLite3::escapeString($text)."', '".$embedType."', '".SQLite3::escapeString($embedData)."', '".$createdAt."', '".$newExpiration."');");
  }
}

/* IV. USER BAN/SUSPENSION LOOKUP */

function isUserCensured($did, $pds) {
  global $db;
  deleteExpired("client_suspensions");
  $ban = $db->query("select count(*) from bans where did='".$did."';");
  $pdsban = $db->query("select count(*) from pds_bans where domain='".$domain."';");
  $suspension = $db->query("select count(*) from client_suspensions where did='".$did."' and expires > ".strtotime('now').";");
  if ($ban > 0 || $pdsban > 0 || $suspension > 0) {
    return true;
  }
  return false;
}

function getUserCensureInfo($did, $pds) {
  
}

/* V. USER BAN/SUSPENSION MANAGEMENT */

/* VI. CREATE TABLES IF NEEDED */
function checkTableExists(string $name):bool {
  global $db;
  $check = $db->query("select name from sqlite_master where type='table' and name='".$name."'");
  return $check ? true : false;
}

function findOrCreateBansTable(): void {
  global $db;
  $check = checkTableExists('bans');
  if (!$check) {
    $db->exec('CREATE TABLE "bans" (
	"did"	TEXT NOT NULL UNIQUE,
	"reason"	TEXT,
	PRIMARY KEY("did")
);');
  }
  return;
}

function findOrCreateSuspensionsTable(): void {
  global $db;
  $check = checkTableExists('client_suspensions');
  if (!$check) {
    $db->exec('CREATE TABLE "client_suspensions" (
	"id"	INTEGER NOT NULL UNIQUE,
	"did"	TEXT NOT NULL,
	"reason"	TEXT,
	"expires"	INTEGER NOT NULL,
	PRIMARY KEY("id")
);');
  }
  return;
}

function findOrCreateFeedsTable(): void {
  global $db;
  $check = checkTableExists('feed_cache');
  if (!$check) {
    $db->exec('CREATE TABLE "feed_cache" (
    	"at_uri"	TEXT NOT NULL UNIQUE,
    	"title"	TEXT NOT NULL,
    	"description"	TEXT NOT NULL,
    	"avatar"	TEXT NOT NULL,
    	"creator_did"	TEXT NOT NULL,
    	"expires"	INTEGER NOT NULL,
    	PRIMARY KEY("at_uri")
    );');
  }
  return;
}

function findOrCreatePdsBans(): void {
  global $db;
  $check = checkTableExists('pds_bans');
  if (!$check) {
    $db->exec('CREATE TABLE "pds_bans" (
    	"domain"	TEXT NOT NULL UNIQUE,
    	"reason"	TEXT
    );');
  }
  return;
}

function findOrCreatePlcTable(): void {
  global $db;
  $check = checkTableExists('user_cache');
  if (!$check) {
    $db->exec('CREATE TABLE "plc_cache" (
    	"did"	TEXT NOT NULL UNIQUE,
    	"plcdoc"	TEXT NOT NULL,
    	"expires"	INTEGER NOT NULL,
    	PRIMARY KEY("did")
    );');
  }
  return;
}

function findOrCreatePostTable(): void {
  global $db;
  $check = checkTableExists('user_cache');
  if (!$check) {
    $db->exec('CREATE TABLE "post_cache" (
    	"rkey"	TEXT NOT NULL UNIQUE,
    	"did"	TEXT NOT NULL,
    	"text"	TEXT,
    	"embed_type"	TEXT,
    	"embed_data"	TEXT,
      "created_at" TEXT,
    	"expires"	INTEGER,
    	PRIMARY KEY("rkey")
    );');
  }
}

function findOrCreateMinidocTable(): void {
  global $db;
  $check = checkTableExists('minidoc_cache');
  if (!$check) {
    $db->exec('CREATE TABLE "minidoc_cache" (
    	"handle"	TEXT NOT NULL UNIQUE,
    	"did"	TEXT NOT NULL UNIQUE,
    	"pds"	TEXT NOT NULL,
    	"signing_key"	NOT NULL,
    	"expires"	INTEGER,
    	PRIMARY KEY("handle")
    );');
  }
  return;
}

function findOrCreateUserTable(): void {
  global $db;
  $check = checkTableExists('post_cache');
  if (!$check) {
    $db->exec('CREATE TABLE "post_cache" (
    	"rkey"	TEXT NOT NULL UNIQUE,
    	"did"	TEXT NOT NULL,
    	"text"	TEXT,
    	"embed_type"	TEXT,
    	"embed_data"	TEXT,
    	"expires"	INTEGER,
    	PRIMARY KEY("rkey")
    );');
  }
  return;
}

?>