<?php

declare(strict_types=1);

/** Separate read-only observations. Only newly owned objects/files may be changed. */
function v4viewsConfig(string $stage): array
{
    if (!is_dir($stage) || is_link($stage) || realpath($stage)!==$stage || (fileperms($stage)&0077)!==0) throw new RuntimeException('Private observer stage required');
    $m=json_decode((string)file_get_contents($stage.'/MANIFEST.json'),true,64,JSON_THROW_ON_ERROR);
    $files=['source/libs/NetzfahrplanV4Bilanzierung.php','source/libs/NetzfahrplanV4Messaufnahme.php','source/libs/NetzfahrplanV4Messsicht.php',
        'source/examples/V4SeparatedObservation/runtime.php','source/examples/V4SeparatedObservation/install.php','config.json','policy.json','INVENTORY.json'];
    if (($m['scope']??null)!=='passive_separated_observation' || array_keys($m['hashes']??[])!==$files) throw new RuntimeException('Unexpected observer manifest');
    foreach($files as $name){$p=$stage.'/'.$name;if(is_link($p)||!is_file($p)||realpath($p)!==$p||hash_file('sha256',$p)!==$m['hashes'][$name])throw new RuntimeException('Observer source drift: '.$name);}
    require_once $stage.'/source/libs/NetzfahrplanV4Messsicht.php';
    $c=\Belevo\EnelixEMS\NetzfahrplanV4Messaufnahme::configuration(json_decode((string)file_get_contents($stage.'/config.json'),true,64,JSON_THROW_ON_ERROR));
    $p=\Belevo\EnelixEMS\NetzfahrplanV4Messsicht::policy(json_decode((string)file_get_contents($stage.'/policy.json'),true,64,JSON_THROW_ON_ERROR),$c);
    if($c['reportedInventorySha256']!==$m['hashes']['INVENTORY.json'])throw new RuntimeException('Inventory identity differs');
    return [$c,$p];
}

function v4viewsMarker(array $c): string { return 'ENELIX separated physical observer v1|'.$c['installationId']; }
function v4viewsChild(int $parent,string $ident): ?int
{
    $result=null;foreach(IPS_GetChildrenIDs($parent) as $id)if(IPS_GetObject($id)['ObjectIdent']===$ident){if($result!==null)throw new RuntimeException('Duplicate observer object');$result=$id;}
    return $result;
}
function v4viewsAssert(int $id,int $parent,string $ident,int $type,string $marker): void
{
    $o=IPS_GetObject($id);if($o['ParentID']!==$parent||$o['ObjectIdent']!==$ident||$o['ObjectType']!==$type||$o['ObjectInfo']!==$marker)throw new RuntimeException('Observer object ownership mismatch');
    if($type===2 && IPS_GetVariable($id)['VariableType']!==3)throw new RuntimeException('Observer diagnosis must be string');
}
function v4viewsRead(int $id): array
{
    if(!IPS_VariableExists($id))throw new RuntimeException('Missing numeric source');
    $a=IPS_GetVariable($id);$o=IPS_GetObject($id);
    if(!in_array($a['VariableType'],[1,2],true))throw new RuntimeException('Non-numeric source');
    return ['value'=>GetValue($id),'updated'=>(int)$a['VariableUpdated'],'changed'=>(int)$a['VariableChanged'],'parentID'=>$o['ParentID'],'ident'=>$o['ObjectIdent']];
}
function v4viewsJson(string $path,array $data): void
{
    if(is_link($path)||realpath(dirname($path))!==dirname($path)||(fileperms(dirname($path))&0077)!==0)throw new RuntimeException('Private observer output required');
    $tmp=tempnam(dirname($path),'.views-');if($tmp===false)throw new RuntimeException('Cannot create observer report');
    try{$json=json_encode($data,JSON_THROW_ON_ERROR|JSON_PRETTY_PRINT|JSON_PRESERVE_ZERO_FRACTION)."\n";
        if(file_put_contents($tmp,$json,LOCK_EX)!==strlen($json)||!chmod($tmp,0644)||!rename($tmp,$path))throw new RuntimeException('Cannot store observer report');
    }finally{if(is_file($tmp))unlink($tmp);}
}
function v4viewsRun(string $stage,int $category): array
{
    if(!function_exists('IPS_GetKernelVersion'))throw new RuntimeException('Run inside Symcon');
    [$c,$policy]=v4viewsConfig($stage);$marker=v4viewsMarker($c);
    v4viewsAssert($category,0,'ENELIX_V4_SEPARATED_OBSERVATION',0,$marker);
    $ids=[];foreach(['PhysicalLoad','AllocationModel','ObservationStatus'] as $key){
        $id=v4viewsChild($category,$key);if($id===null)throw new RuntimeException('Observer object missing');v4viewsAssert($id,$category,$key,2,$marker);$ids[$key]=$id;}
    $lock='ENELIX.V4.SeparatedView.'.$c['installationId'];if(!IPS_SemaphoreEnter($lock,0))return ['status'=>'busy','controlEnabled'=>false];
    try{
        try{
            $raw=\Belevo\EnelixEMS\NetzfahrplanV4Messaufnahme::capture($c,'v4viewsRead',static fn():int=>time());
            $view=\Belevo\EnelixEMS\NetzfahrplanV4Messsicht::calculate($raw,$c,$policy);
            $record=['schemaVersion'=>1,'kind'=>'physical_and_allocation_observation','installationId'=>$c['installationId'],'capturedAt'=>$raw['capturedAt'],
                'capture'=>$raw,'views'=>$view,'trainingEligible'=>false,'controlEnabled'=>false];
            $dir=$stage.'/data';if(is_link($dir)||realpath($dir)!==$dir||(fileperms($dir)&0077)!==0)throw new RuntimeException('Private data directory required');
            $path=\Belevo\EnelixEMS\NetzfahrplanV4Messaufnahme::append($dir,$record);
            // Derived-only files readable to authorized agent through a mode-0700 stage/data directory.
            // Original collector files and permissions are never touched.
            if(!chmod($path,0644))throw new RuntimeException('Cannot expose selected derived observation');
            $status=['status'=>'recorded','capturedAt'=>$raw['capturedAt'],'sourceCount'=>count($raw['raw']),'journal'=>$path,
                'physicalLoadStatus'=>$view['physicalLoad']['status'],'allocationModelStatus'=>$view['allocationModel']['status'],
                'solarOriginStatus'=>$view['solarOrigin']['status'],'trainingEligible'=>false,'controlEnabled'=>false];
            v4viewsJson($dir.'/LATEST.json',$record);
            SetValue($ids['PhysicalLoad'],json_encode(['captureAt'=>$raw['capturedAt'],'physical'=>$view['physicalLoad'],'solarAcAlternative'=>$view['solarAcAlternative'],'trainingEligible'=>false],JSON_THROW_ON_ERROR));
            SetValue($ids['AllocationModel'],json_encode(['captureAt'=>$raw['capturedAt'],'model'=>$view['allocationModel'],'storage'=>$view['storageFeedback'],'canDispatch'=>false],JSON_THROW_ON_ERROR));
        }catch(Throwable $e){
            $status=['status'=>'observation_error','at'=>gmdate('c'),'errorType'=>get_class($e),'sourceLine'=>$e->getLine(),'trainingEligible'=>false,'controlEnabled'=>false];
            // Never leave a stale numeric proposal in the new diagnosis variables.
            SetValue($ids['PhysicalLoad'],json_encode($status,JSON_THROW_ON_ERROR));SetValue($ids['AllocationModel'],json_encode($status,JSON_THROW_ON_ERROR));
            try{v4viewsJson($stage.'/data/LATEST.json',$status);}catch(Throwable $ignored){}
        }
        SetValue($ids['ObservationStatus'],json_encode($status,JSON_THROW_ON_ERROR));v4viewsJson($stage.'/data/STATUS.json',$status);return $status;
    }finally{IPS_SemaphoreLeave($lock);}
}
function v4viewsStop(string $stage,int $category): void
{
    [$c,$p]=v4viewsConfig($stage);$marker=v4viewsMarker($c);v4viewsAssert($category,0,'ENELIX_V4_SEPARATED_OBSERVATION',0,$marker);
    $id=v4viewsChild($category,'Observe');if($id===null)throw new RuntimeException('Observer script missing');v4viewsAssert($id,$category,'Observe',3,$marker);
    if(!IPS_SetScriptTimer($id,0))throw new RuntimeException('Cannot stop observer');
    $s=['status'=>'stopped','at'=>gmdate('c'),'controlEnabled'=>false,'existingCollectorChanged'=>false];
    foreach(['PhysicalLoad','AllocationModel','ObservationStatus'] as $key){$var=v4viewsChild($category,$key);if($var===null)throw new RuntimeException('Observer status missing');v4viewsAssert($var,$category,$key,2,$marker);SetValue($var,json_encode($s,JSON_THROW_ON_ERROR));}
    v4viewsJson($stage.'/data/STATUS.json',$s);v4viewsJson($stage.'/data/LATEST.json',$s);
}