<?php
require_once __DIR__.'/inc/helpers.php';
header('Content-Type: application/json; charset=utf-8');
function out($ok,$data,$mode='n/a'){
  echo json_encode(['ok'=>$ok,'data_mode'=>$mode,
   'licence'=>'Open data licence, attribution required',
   'citation'=>'Districthive Research Labs · The Skerðingsstaðir Experiment',
   'data'=>$data]); exit;
}
$key=$_GET['key']??'';
$kh=hash('sha256',$key);
$row=$key?db()->prepare('SELECT id FROM api_keys WHERE key_hash=? AND active=1'):null;
if($row){$row->execute([$kh]);$row=$row->fetch();}
if(!$row){ http_response_code(401); out(false,['error'=>'valid key required; request one via the About page']); }
db()->prepare('UPDATE api_keys SET last_used_at=NOW() WHERE key_hash=?')->execute([$kh]);
log_activity('api',$_GET['action']??'?', substr(($_GET['stream']??''),0,40));

$action=$_GET['action']??'streams';
if($action==='streams'){
  $q=db()->query("SELECT s.code,s.label,s.unit,s.mode,s.visibility,i.product,i.cadence_min FROM streams s JOIN instruments i ON i.id=s.instrument_id WHERE s.visibility IN ('public','keyed')");
  out(true,$q->fetchAll());
}
if($action==='readings'){
  $s=stream_by_code(preg_replace('/[^a-z0-9_]/','',$_GET['stream']??''));
  if(!$s||$s['visibility']==='hidden') out(false,['error'=>'unknown or restricted stream']);
  $from=($_GET['from']??date('Y-m-d',strtotime('-7 days'))).' 00:00:00';
  $to=($_GET['to']??date('Y-m-d')).' 23:59:59';
  out(true,array_map(fn($r)=>[$r['ts'],(float)$r['value']],series($s,$from,$to,2000)),$s['mode']);
}
if($action==='events'){
  $cls=preg_replace('/[^a-z]/','',$_GET['class']??'');
  $sql="SELECT ts,class,detail FROM events WHERE is_public=1".($cls?" AND class=".db()->quote($cls):"")." ORDER BY ts DESC LIMIT 500";
  out(true,db()->query($sql)->fetchAll());
}
if($action==='checksums'){
  $p=$_GET['path']??''; $q=db()->prepare('SELECT path,sha256,bytes,pulled_at FROM files_raw WHERE path=?');
  $q->execute([$p]); out(true,$q->fetch()?:['error'=>'not found']);
}
out(false,['error'=>'unknown action']);