<?php

declare(strict_types=1);

namespace App\Support\Baselines;

use App\Models\BaselineProfile;
use App\Models\BaselineTenantAssignment;
use App\Models\Finding;
use App\Models\OperationRun;
use App\Models\Tenant;

final class BaselineCompareStats
{
    /**
     * @param  array<string, int>  $severityCounts
     */
    private function __construct(
        public readonly string $state,
        public readonly ?string $message,
        public readonly ?string $profileName,
        public readonly ?int $profileId,
        public readonly ?int $snapshotId,
        public readonly ?int $operationRunId,
        public readonly ?int $findingsCount,
        public readonly array $severityCounts,
        public readonly ?string $lastComparedHuman,
        public readonly ?string $lastComparedIso,
        public readonly ?string $failureReason,
    ) {}

    public static function forTenant(?Tenant $tenant): self
    {
        if (! $tenant instanceof Tenant) {
            return self::empty('no_tenant', 'No tenant selected.');
        }

        $assignment = BaselineTenantAssignment::query()
            ->where('tenant_id', $tenant->getKey())
            ->first();

        if (! $assignment instanceof BaselineTenantAssignment) {
            return self::empty(
                'no_assignment',
                'This tenant has no baseline assignment. A workspace manager can assign a baseline profile to this tenant.',
            );
        }

        $profile = $assignment->baselineProfile;

        if (! $profile instanceof BaselineProfile) {
            return self::empty(
                'no_assignment',
                'The assigned baseline profile no longer exists.',
            );
        }

        $profileName = (string) $profile->name;
        $profileId = (int) $profile->getKey();
        $snapshotId = $profile->active_snapshot_id !== null ? (int) $profile->active_snapshot_id : null;

        if ($snapshotId === null) {
            return self::empty(
                'no_snapshot',
                'The baseline profile has no active snapshot yet. A workspace manager needs to capture a snapshot first.',
                profileName: $profileName,
                profileId: $profileId,
            );
        }

        $latestRun = OperationRun::query()
            ->where('tenant_id', $tenant->getKey())
            ->where('type', 'baseline_compare')
            ->latest('id')
            ->first();

        // Active run (queued/running)
        if ($latestRun instanceof OperationRun && in_array($latestRun->status, ['queued', 'running'], true)) {
            return new self(
                state: 'comparing',
                message: 'A baseline comparison is currently in progress.',
                profileName: $profileName,
                profileId: $profileId,
                snapshotId: $snapshotId,
                operationRunId: (int) $latestRun->getKey(),
                findingsCount: null,
                severityCounts: [],
                lastComparedHuman: null,
                lastComparedIso: null,
                failureReason: null,
            );
        }

        // Failed run — explicit error state
        if ($latestRun instanceof OperationRun && $latestRun->outcome === 'failed') {
            $failureSummary = is_array($latestRun->failure_summary) ? $latestRun->failure_summary : [];
            $failureReason = $failureSummary['message']
                ?? $failureSummary['reason']
                ?? 'The comparison job failed. Check the run details for more information.';

            return new self(
                state: 'failed',
                message: (string) $failureReason,
                profileName: $profileName,
                profileId: $profileId,
                snapshotId: $snapshotId,
                operationRunId: (int) $latestRun->getKey(),
                findingsCount: null,
                severityCounts: [],
                lastComparedHuman: $latestRun->finished_at?->diffForHumans(),
                lastComparedIso: $latestRun->finished_at?->toIso8601String(),
                failureReason: (string) $failureReason,
            );
        }

        $lastComparedHuman = null;
        $lastComparedIso = null;

        if ($latestRun instanceof OperationRun && $latestRun->finished_at !== null) {
            $lastComparedHuman = $latestRun->finished_at->diffForHumans();
            $lastComparedIso = $latestRun->finished_at->toIso8601String();
        }

        $scopeKey = 'baseline_profile:'.$profile->getKey();

        // Single grouped query instead of 4 separate COUNT queries
        $severityRows = Finding::query()
            ->where('tenant_id', $tenant->getKey())
            ->where('finding_type', Finding::FINDING_TYPE_DRIFT)
            ->where('source', 'baseline.compare')
            ->where('scope_key', $scopeKey)
            ->whereIn('status', Finding::openStatusesForQuery())
            ->selectRaw('severity, count(*) as cnt')
            ->groupBy('severity')
            ->pluck('cnt', 'severity');

        $totalFindings = (int) $severityRows->sum();
        $severityCounts = [
            'high' => (int) ($severityRows[Finding::SEVERITY_HIGH] ?? 0),
            'medium' => (int) ($severityRows[Finding::SEVERITY_MEDIUM] ?? 0),
            'low' => (int) ($severityRows[Finding::SEVERITY_LOW] ?? 0),
        ];

        if ($totalFindings > 0) {
            return new self(
                state: 'ready',
                message: null,
                profileName: $profileName,
                profileId: $profileId,
                snapshotId: $snapshotId,
                operationRunId: $latestRun instanceof OperationRun ? (int) $latestRun->getKey() : null,
                findingsCount: $totalFindings,
                severityCounts: $severityCounts,
                lastComparedHuman: $lastComparedHuman,
                lastComparedIso: $lastComparedIso,
                failureReason: null,
            );
        }

        if ($latestRun instanceof OperationRun && $latestRun->status === 'completed' && $latestRun->outcome === 'succeeded') {
            return new self(
                state: 'ready',
                message: 'No open drift findings for this baseline comparison. The tenant matches the baseline.',
                profileName: $profileName,
                profileId: $profileId,
                snapshotId: $snapshotId,
                operationRunId: (int) $latestRun->getKey(),
                findingsCount: 0,
                severityCounts: $severityCounts,
                lastComparedHuman: $lastComparedHuman,
                lastComparedIso: $lastComparedIso,
                failureReason: null,
            );
        }

        return new self(
            state: 'idle',
            message: 'Baseline profile is assigned and has a snapshot. Run "Compare Now" to check for drift.',
            profileName: $profileName,
            profileId: $profileId,
            snapshotId: $snapshotId,
            operationRunId: null,
            findingsCount: null,
            severityCounts: $severityCounts,
            lastComparedHuman: $lastComparedHuman,
            lastComparedIso: $lastComparedIso,
            failureReason: null,
        );
    }

    /**
     * Create a DTO for widget consumption (only open/new findings).
     */
    public static function forWidget(?Tenant $tenant): self
    {
        if (! $tenant instanceof Tenant) {
            return self::empty('no_tenant', null);
        }

        $assignment = BaselineTenantAssignment::query()
            ->where('tenant_id', $tenant->getKey())
            ->with('baselineProfile')
            ->first();

        if (! $assignment instanceof BaselineTenantAssignment || $assignment->baselineProfile === null) {
            return self::empty('no_assignment', null);
        }

        $profile = $assignment->baselineProfile;
        $scopeKey = 'baseline_profile:'.$profile->getKey();

        $severityRows = Finding::query()
            ->where('tenant_id', $tenant->getKey())
            ->where('finding_type', Finding::FINDING_TYPE_DRIFT)
            ->where('source', 'baseline.compare')
            ->where('scope_key', $scopeKey)
            ->where('status', Finding::STATUS_NEW)
            ->selectRaw('severity, count(*) as cnt')
            ->groupBy('severity')
            ->pluck('cnt', 'severity');

        $totalFindings = (int) $severityRows->sum();

        $latestRun = OperationRun::query()
            ->where('tenant_id', $tenant->getKey())
            ->where('type', 'baseline_compare')
            ->where('context->baseline_profile_id', (string) $profile->getKey())
            ->whereNotNull('completed_at')
            ->latest('completed_at')
            ->first();

        return new self(
            state: $totalFindings > 0 ? 'ready' : 'idle',
            message: null,
            profileName: (string) $profile->name,
            profileId: (int) $profile->getKey(),
            snapshotId: $profile->active_snapshot_id !== null ? (int) $profile->active_snapshot_id : null,
            operationRunId: $latestRun instanceof OperationRun ? (int) $latestRun->getKey() : null,
            findingsCount: $totalFindings,
            severityCounts: [
                'high' => (int) ($severityRows[Finding::SEVERITY_HIGH] ?? 0),
                'medium' => (int) ($severityRows[Finding::SEVERITY_MEDIUM] ?? 0),
                'low' => (int) ($severityRows[Finding::SEVERITY_LOW] ?? 0),
            ],
            lastComparedHuman: $latestRun?->finished_at?->diffForHumans(),
            lastComparedIso: $latestRun?->finished_at?->toIso8601String(),
            failureReason: null,
        );
    }

    private static function empty(
        string $state,
        ?string $message,
        ?string $profileName = null,
        ?int $profileId = null,
    ): self {
        return new self(
            state: $state,
            message: $message,
            profileName: $profileName,
            profileId: $profileId,
            snapshotId: null,
            operationRunId: null,
            findingsCount: null,
            severityCounts: [],
            lastComparedHuman: null,
            lastComparedIso: null,
            failureReason: null,
        );
    }
}