<?php

declare(strict_types=1);

namespace App\Support\ReviewPublicationResolution;

use App\Models\EnvironmentReview;
use App\Models\ReviewPublicationResolutionCase;
use App\Models\ReviewPublicationResolutionStep;
use App\Support\OperationRunOutcome;
use App\Support\OperationRunStatus;
use Illuminate\Support\Collection;

final class ReviewPublicationStepPlanner
{
    public function __construct(
        private readonly ReviewPublicationProofResolver $proofResolver,
    ) {}

    /**
     * @param  array<string, mixed>  $readiness
     * @return array{
     *   steps:list<array<string, mixed>>,
     *   case_status:ReviewPublicationResolutionCaseStatus,
     *   current_step_key:?string
     * }
     */
    public function plan(EnvironmentReview $review, array $readiness, ?ReviewPublicationResolutionCase $case = null): array
    {
        $existing = $case instanceof ReviewPublicationResolutionCase
            ? $case->loadMissing(['steps.operationRun'])->steps->keyBy('step_key')
            : new Collection;

        $steps = [];

        foreach ($this->relevantStepKeys($readiness, $existing) as $index => $stepKey) {
            $steps[] = $this->stepPlan(
                review: $review,
                readiness: $readiness,
                stepKey: $stepKey,
                position: $index + 1,
                existingStep: $existing->get($stepKey->value),
            );
        }

        $steps = $this->activateFirstIncompleteStep($steps);
        $currentStep = collect($steps)->first(
            static fn (array $step): bool => in_array($step['status'], [
                ReviewPublicationResolutionStepStatus::Actionable->value,
                ReviewPublicationResolutionStepStatus::Running->value,
                ReviewPublicationResolutionStepStatus::Failed->value,
            ], true),
        );

        $caseStatus = $this->caseStatus($steps, is_array($currentStep) ? (string) $currentStep['step_key'] : null);

        return [
            'steps' => $steps,
            'case_status' => $caseStatus,
            'current_step_key' => is_array($currentStep) ? (string) $currentStep['step_key'] : null,
        ];
    }

    /**
     * @param  array<string, mixed>  $readiness
     * @return array<string, mixed>
     */
    private function stepPlan(
        EnvironmentReview $review,
        array $readiness,
        ReviewPublicationResolutionStepKey $stepKey,
        int $position,
        ?ReviewPublicationResolutionStep $existingStep,
    ): array {
        $status = $this->baseStatus($stepKey, $readiness, $existingStep);
        $proof = $this->proofResolver->proofFor($stepKey, $review);

        if ($existingStep instanceof ReviewPublicationResolutionStep
            && in_array($status, [
                ReviewPublicationResolutionStepStatus::Running,
                ReviewPublicationResolutionStepStatus::Failed,
            ], true)) {
            $proof = [
                'proof_type' => is_string($existingStep->proof_type) ? $existingStep->proof_type : $proof['proof_type'],
                'proof_id' => is_numeric($existingStep->proof_id) ? (int) $existingStep->proof_id : $proof['proof_id'],
                'proof_status' => is_string($existingStep->proof_status) ? $existingStep->proof_status : $proof['proof_status'],
                'operation_run_id' => is_numeric($existingStep->operation_run_id) ? (int) $existingStep->operation_run_id : $proof['operation_run_id'],
            ];
        }

        return [
            'position' => $position,
            'step_key' => $stepKey->value,
            'status' => $status->value,
            'primary_action_key' => $stepKey->primaryActionKey(),
            'operation_run_id' => $proof['operation_run_id'],
            'proof_type' => $proof['proof_type'],
            'proof_id' => $proof['proof_id'],
            'proof_status' => $proof['proof_status'],
            'summary' => $this->summary($stepKey, $readiness, $status),
            'metadata' => [
                'readiness_fingerprint' => (string) $readiness['fingerprint'],
                'planned_at' => now()->toIso8601String(),
            ],
        ];
    }

    /**
     * @param  array<string, mixed>  $readiness
     */
    private function baseStatus(
        ReviewPublicationResolutionStepKey $stepKey,
        array $readiness,
        ?ReviewPublicationResolutionStep $existingStep,
    ): ReviewPublicationResolutionStepStatus {
        $readinessStatus = $this->readinessStatus($stepKey, $readiness);

        if ($readinessStatus === ReviewPublicationResolutionStepStatus::Completed) {
            return ReviewPublicationResolutionStepStatus::Completed;
        }

        if ($existingStep instanceof ReviewPublicationResolutionStep) {
            if ($stepKey === ReviewPublicationResolutionStepKey::ReturnToPublication
                && $existingStep->statusEnum() === ReviewPublicationResolutionStepStatus::Completed) {
                return ReviewPublicationResolutionStepStatus::Completed;
            }

            if ($existingStep->statusEnum() === ReviewPublicationResolutionStepStatus::Running && $existingStep->operationRun?->status !== OperationRunStatus::Completed->value) {
                return ReviewPublicationResolutionStepStatus::Running;
            }

            if ($existingStep->operationRun?->status === OperationRunStatus::Completed->value
                && in_array((string) $existingStep->operationRun->outcome, [OperationRunOutcome::Failed->value, OperationRunOutcome::Blocked->value], true)) {
                return ReviewPublicationResolutionStepStatus::Failed;
            }

        }

        return $readinessStatus;
    }

    /**
     * @param  Collection<string, ReviewPublicationResolutionStep>  $existing
     * @return list<ReviewPublicationResolutionStepKey>
     */
    private function relevantStepKeys(array $readiness, Collection $existing): array
    {
        $keys = [
            ReviewPublicationResolutionStepKey::ValidateReviewReadiness,
        ];

        if (((array) ($readiness['missing_report_dimensions'] ?? [])) !== []
            || $this->hasExistingStep($existing, ReviewPublicationResolutionStepKey::CompleteRequiredReports)) {
            $keys[] = ReviewPublicationResolutionStepKey::CompleteRequiredReports;
        }

        if ((bool) ($readiness['evidence_incomplete'] ?? true)
            || $this->hasExistingStep($existing, ReviewPublicationResolutionStepKey::CollectEvidenceSnapshot)) {
            $keys[] = ReviewPublicationResolutionStepKey::CollectEvidenceSnapshot;
        }

        if ((bool) ($readiness['review_requires_refresh'] ?? true)
            || $this->hasExistingStep($existing, ReviewPublicationResolutionStepKey::RefreshReviewComposition)) {
            $keys[] = ReviewPublicationResolutionStepKey::RefreshReviewComposition;
        }

        if (! (bool) ($readiness['has_ready_export'] ?? false)
            || $this->hasExistingStep($existing, ReviewPublicationResolutionStepKey::GenerateReviewPack)) {
            $keys[] = ReviewPublicationResolutionStepKey::GenerateReviewPack;
        }

        $keys[] = ReviewPublicationResolutionStepKey::ReturnToPublication;

        return $keys;
    }

    /**
     * @param  Collection<string, ReviewPublicationResolutionStep>  $existing
     */
    private function hasExistingStep(Collection $existing, ReviewPublicationResolutionStepKey $stepKey): bool
    {
        $step = $existing->get($stepKey->value);

        return $step instanceof ReviewPublicationResolutionStep
            && $step->statusEnum() !== ReviewPublicationResolutionStepStatus::Superseded;
    }

    /**
     * @param  array<string, mixed>  $readiness
     */
    private function readinessStatus(
        ReviewPublicationResolutionStepKey $stepKey,
        array $readiness,
    ): ReviewPublicationResolutionStepStatus {
        return match ($stepKey) {
            ReviewPublicationResolutionStepKey::ValidateReviewReadiness => ReviewPublicationResolutionStepStatus::Completed,
            ReviewPublicationResolutionStepKey::CompleteRequiredReports => ((array) ($readiness['missing_report_dimensions'] ?? [])) === []
                ? ReviewPublicationResolutionStepStatus::Completed
                : ReviewPublicationResolutionStepStatus::Pending,
            ReviewPublicationResolutionStepKey::CollectEvidenceSnapshot => (bool) ($readiness['evidence_incomplete'] ?? true)
                ? ReviewPublicationResolutionStepStatus::Pending
                : ReviewPublicationResolutionStepStatus::Completed,
            ReviewPublicationResolutionStepKey::RefreshReviewComposition => (bool) ($readiness['review_requires_refresh'] ?? true)
                ? ReviewPublicationResolutionStepStatus::Pending
                : ReviewPublicationResolutionStepStatus::Completed,
            ReviewPublicationResolutionStepKey::GenerateReviewPack => (bool) ($readiness['has_ready_export'] ?? false)
                ? ReviewPublicationResolutionStepStatus::Completed
                : ReviewPublicationResolutionStepStatus::Pending,
            ReviewPublicationResolutionStepKey::ReturnToPublication => ReviewPublicationResolutionStepStatus::Pending,
        };
    }

    /**
     * @param  list<array<string, mixed>>  $steps
     * @return list<array<string, mixed>>
     */
    private function activateFirstIncompleteStep(array $steps): array
    {
        foreach ($steps as $index => $step) {
            if ($step['status'] !== ReviewPublicationResolutionStepStatus::Pending->value) {
                continue;
            }

            $steps[$index]['status'] = ReviewPublicationResolutionStepStatus::Actionable->value;
            $steps[$index]['summary']['state_description'] = 'Ready for operator action.';

            break;
        }

        return $steps;
    }

    /**
     * @param  list<array<string, mixed>>  $steps
     */
    private function caseStatus(array $steps, ?string $currentStepKey): ReviewPublicationResolutionCaseStatus
    {
        if ($currentStepKey === null) {
            return ReviewPublicationResolutionCaseStatus::Completed;
        }

        $currentStep = collect($steps)->firstWhere('step_key', $currentStepKey);

        if (is_array($currentStep) && $currentStep['status'] === ReviewPublicationResolutionStepStatus::Running->value) {
            return ReviewPublicationResolutionCaseStatus::WaitingForRun;
        }

        if (is_array($currentStep) && $currentStep['status'] === ReviewPublicationResolutionStepStatus::Failed->value) {
            return ReviewPublicationResolutionCaseStatus::Blocked;
        }

        if ($currentStepKey === ReviewPublicationResolutionStepKey::ReturnToPublication->value) {
            return ReviewPublicationResolutionCaseStatus::ReadyToContinue;
        }

        return ReviewPublicationResolutionCaseStatus::InProgress;
    }

    /**
     * @param  array<string, mixed>  $readiness
     * @return array<string, mixed>
     */
    private function summary(
        ReviewPublicationResolutionStepKey $stepKey,
        array $readiness,
        ReviewPublicationResolutionStepStatus $status,
    ): array {
        return [
            'label' => $stepKey->label(),
            'description' => match ($stepKey) {
                ReviewPublicationResolutionStepKey::ValidateReviewReadiness => 'Review readiness has been evaluated from current evidence and section state.',
                ReviewPublicationResolutionStepKey::CompleteRequiredReports => 'Required report-backed evidence dimensions must be current before publication can continue.',
                ReviewPublicationResolutionStepKey::CollectEvidenceSnapshot => 'The evidence snapshot must be complete and current for the review output.',
                ReviewPublicationResolutionStepKey::RefreshReviewComposition => 'Review sections must be recomposed from current evidence before publication.',
                ReviewPublicationResolutionStepKey::GenerateReviewPack => 'A current review pack is required before returning to publication.',
                ReviewPublicationResolutionStepKey::ReturnToPublication => 'Return to the review publication action after blockers are resolved.',
            },
            'state_description' => $status === ReviewPublicationResolutionStepStatus::Completed
                ? 'Requirement is satisfied.'
                : 'Waiting for prerequisite steps.',
            'publication_blocker_count' => count((array) ($readiness['publication_blockers'] ?? [])),
            'missing_report_dimensions' => array_values((array) ($readiness['missing_report_dimensions'] ?? [])),
            'evidence_state' => (string) ($readiness['evidence_state'] ?? ''),
            'review_status' => (string) ($readiness['review_status'] ?? ''),
            'has_ready_export' => (bool) ($readiness['has_ready_export'] ?? false),
        ];
    }
}