<?php

declare(strict_types=1);

namespace LIT\MCP\Tests\Unit\Integrations\Divi\Design;

use LIT\MCP\Integrations\Divi\Design\DesignArea;
use LIT\MCP\Integrations\Divi\Design\DesignChange;
use LIT\MCP\Integrations\Divi\Design\DesignLock;
use LIT\MCP\Integrations\Divi\Design\DesignPlan;
use LIT\MCP\Integrations\Divi\Design\SnapshotStore;
use LIT\MCP\Integrations\Divi\Design\SnapshotTooLarge;
use LIT\MCP\Integrations\Divi\Library\UsageReport;
use LIT\MCP\Integrations\Divi\Release\DiviFeature;
use LIT\MCP\Integrations\Divi\Release\DiviLocked;
use LIT\MCP\Integrations\Divi\Release\ReleaseGate;
use LIT\MCP\Integrations\Divi\Release\ReleaseState;
use LIT\MCP\Integrations\Divi\Release\ReleaseStatus;
use LIT\MCP\Abilities\WriteFailed;
use LIT\MCP\Tests\Support\FakeChangeLog;
use LIT\MCP\Tests\Support\ReleaseMatrices;
use LIT\MCP\Tests\Unit\TestCase;
use Brain\Monkey\Functions;
use Mockery;
use RuntimeException;

final class DesignChangeTest extends TestCase
{
    /** @var array<string, mixed> Options as add_option()/delete_option() see them (DesignLock). */
    private array $options = [];

    protected function setUp(): void
    {
        parent::setUp();
        $this->options = [];
        Functions\when('add_option')->alias(function (string $name, mixed $value = ''): bool {
            if (array_key_exists($name, $this->options)) {
                return false;
            }
            $this->options[$name] = $value;

            return true;
        });
        Functions\when('get_option')->alias(fn (string $name, mixed $default = false): mixed => $this->options[$name] ?? $default);
        Functions\when('delete_option')->alias(function (string $name): bool {
            unset($this->options[$name]);

            return true;
        });
    }

    /**
     * A DesignArea over an array; the first $failWrites calls of write()/restore() throw, $differences are the
     * value warnings of differences().
     */
    private static function area(
        array &$stored,
        int $failWrites = 0,
        bool $verify = true,
        array $differences = []
    ): DesignArea {
        return new class ($stored, $failWrites, $verify, $differences) implements DesignArea {
            public array $writes = [];

            public array $restores = [];

            public function __construct(
                private array &$stored,
                private int $failWrites,
                private bool $verify,
                private array $differences
            ) {
            }

            public function name(): string
            {
                return 'presets';
            }

            public function label(): string
            {
                return 'Presets';
            }

            public function feature(): DiviFeature
            {
                return DiviFeature::PresetWrite;
            }

            public function raw(): array
            {
                return $this->stored;
            }

            public function rev(array $raw): string
            {
                return substr(md5((string) json_encode($raw)), 0, 12);
            }

            public function write(array $raw, bool $mayRemove): array
            {
                $this->writes[] = [$raw, $mayRemove];
                if ($this->failWrites > 0) {
                    --$this->failWrites;
                    throw new RuntimeException('divi refused');
                }
                $this->stored = $raw;

                return $raw;
            }

            public function restore(array $raw): array
            {
                $this->restores[] = $raw;
                if ($this->failWrites > 0) {
                    --$this->failWrites;
                    throw new RuntimeException('divi refused the restore');
                }
                $this->stored = $raw;

                return $raw;
            }

            public function verify(array $expected, array $actual): bool
            {
                return $this->verify;
            }

            public function differences(array $expected, array $actual): array
            {
                return $this->differences;
            }
        };
    }

    private static function plan(array $raw, ?UsageReport $usages = null): callable
    {
        return static fn (array $current): DesignPlan => new DesignPlan(
            $raw,
            [['kind' => 'module', 'scope' => 'divi/button', 'id' => 'a', 'name' => 'CTA', 'action' => 'added']],
            'Preset „CTA“ wird angelegt.',
            $usages
        );
    }

    private static function usages(array $blocked = []): UsageReport
    {
        return new UsageReport(1, [['post_id' => 3, 'title' => 'Start', 'status' => 'publish', 'type' => 'page']],
            0, 1, $blocked, 0, false);
    }

    public function testDryRunListsDiffAffectedAndRevAndSavesNothing(): void
    {
        $stored = ['v' => 1];
        $area = self::area($stored);
        $snapshots = Mockery::mock(SnapshotStore::class);
        $snapshots->shouldNotReceive('save');

        $result = (new DesignChange($snapshots, FakeChangeLog::forbidden()))
            ->run('lit/divi-presets-set', $area, [], self::plan(['v' => 2], self::usages()));

        $details = self::assertToolError($result, 'confirm_required');
        self::assertStringContainsString('Preset „CTA“ wird angelegt. Nichts wurde gespeichert (Probelauf).', $result->get_error_message());
        self::assertSame('added', $details['diff'][0]['action']);
        self::assertSame($area->rev(['v' => 1]), $details['design_rev']);
        self::assertSame(3, $details['affected'][0]['post_id']);
        self::assertSame(1, $details['affected_count']);
        self::assertSame([], $area->writes);
    }

    public function testNothingToDoIsNoDryRun(): void
    {
        $stored = ['v' => 1];
        $empty = static fn (array $current): DesignPlan => new DesignPlan($current, [], 'Nichts.');

        $result = (new DesignChange(Mockery::mock(SnapshotStore::class), FakeChangeLog::forbidden()))
            ->run('lit/divi-presets-set', self::area($stored), [], $empty);

        self::assertTrue($result['ok']);
        self::assertSame([], $result['diff']);
        self::assertStringStartsWith('Keine Änderung', $result['summary']);
    }

    public function testStaleDesignRevWritesNothing(): void
    {
        $stored = ['v' => 1];
        $area = self::area($stored);
        $snapshots = Mockery::mock(SnapshotStore::class);
        $snapshots->shouldNotReceive('save');

        $result = (new DesignChange($snapshots, FakeChangeLog::forbidden()))
            ->run('lit/divi-presets-set', $area, ['confirm' => true, 'design_rev' => 'veraltet'], self::plan(['v' => 2]));

        self::assertToolError($result, 'rev_mismatch');
        self::assertStringContainsString('Presets wurden seit dem Probelauf geändert', $result->get_error_message());
        self::assertSame([], $area->writes);
    }

    /** Final review M-9: confirm without design_rev is a missing input, not a stale one. */
    public function testConfirmWithoutDesignRevIsInvalidInput(): void
    {
        $stored = ['v' => 1];
        $area = self::area($stored);
        $snapshots = Mockery::mock(SnapshotStore::class);
        $snapshots->shouldNotReceive('save');

        $result = (new DesignChange($snapshots, FakeChangeLog::forbidden()))
            ->run('lit/divi-presets-set', $area, ['confirm' => true], self::plan(['v' => 2]));

        $details = self::assertToolError($result, 'validation_failed');
        self::assertSame('design_rev fehlt; nichts wurde gespeichert.', $details['message']);
        self::assertSame('aus dem Probelauf übernehmen', $details['fields']['design_rev']);
        self::assertSame([], $area->writes);
    }

    /** Final review I-5: a confirm while another change of the area runs writes nothing. */
    public function testAHeldLockRefusesTheConfirm(): void
    {
        $this->options['lit_mcp_lock_presets'] = time();
        $stored = ['v' => 1];
        $area = self::area($stored);
        $snapshots = Mockery::mock(SnapshotStore::class);
        $snapshots->shouldNotReceive('save');

        $result = (new DesignChange($snapshots, FakeChangeLog::forbidden(), new DesignLock()))->run(
            'lit/divi-presets-set',
            $area,
            ['confirm' => true, 'design_rev' => $area->rev($stored)],
            self::plan(['v' => 2])
        );

        self::assertToolError($result, 'conflict');
        self::assertSame(409, $result->get_error_data()['status']);
        self::assertStringContainsString('andere Änderung an den Presets', $result->get_error_message());
        self::assertSame([], $area->writes);
        self::assertArrayHasKey('lit_mcp_lock_presets', $this->options, 'a foreign lock is not released');
    }

    public function testTheLockIsHeldWhileWritingAndReleasedAfterSuccess(): void
    {
        $stored = ['v' => 1];
        $area = self::area($stored);
        $snapshots = Mockery::mock(SnapshotStore::class);
        $snapshots->expects('save')->andReturnUsing(function (): string {
            self::assertArrayHasKey('lit_mcp_lock_presets', $this->options, 'snapshot under the lock');

            return 'presets-1';
        });
        $snapshots->expects('attachLog')->andReturnUsing(function (): void {
            self::assertArrayHasKey('lit_mcp_lock_presets', $this->options, 'log under the lock');
        });

        $result = (new DesignChange($snapshots, new FakeChangeLog(9)))->run(
            'lit/divi-presets-set',
            $area,
            ['confirm' => true, 'design_rev' => $area->rev($stored)],
            self::plan(['v' => 2])
        );

        self::assertTrue($result['ok']);
        self::assertArrayNotHasKey('lit_mcp_lock_presets', $this->options);
    }

    public function testTheLockIsReleasedAfterAFailedWrite(): void
    {
        $stored = ['v' => 1];
        $area = self::area($stored, 1);
        $snapshots = Mockery::mock(SnapshotStore::class);
        $snapshots->expects('save')->andReturn('presets-1');

        try {
            (new DesignChange($snapshots, FakeChangeLog::forbidden()))->run(
                'lit/divi-presets-set',
                $area,
                ['confirm' => true, 'design_rev' => $area->rev($stored)],
                self::plan(['v' => 2])
            );
            self::fail('expected WriteFailed');
        } catch (WriteFailed) {
            self::assertArrayNotHasKey('lit_mcp_lock_presets', $this->options);
        }
    }

    /** The design_rev is checked against the inventory read under the lock, not before it. */
    public function testTheRevIsCheckedOnTheInventoryReadUnderTheLock(): void
    {
        $stored = ['v' => 1];
        $area = self::area($stored);
        $rev = $area->rev($stored);
        $snapshots = Mockery::mock(SnapshotStore::class);
        $snapshots->shouldNotReceive('save');
        Functions\when('add_option')->alias(function (string $name, mixed $value = '') use (&$stored): bool {
            $stored = ['v' => 'parallel'];
            $this->options[$name] = $value;

            return true;
        });

        $result = (new DesignChange($snapshots, FakeChangeLog::forbidden()))->run(
            'lit/divi-presets-set',
            $area,
            ['confirm' => true, 'design_rev' => $rev],
            self::plan(['v' => 2])
        );

        self::assertToolError($result, 'rev_mismatch');
        self::assertSame([], $area->writes);
        self::assertArrayNotHasKey('lit_mcp_lock_presets', $this->options);
    }

    public function testBlockedUsagesRefuseTheConfirm(): void
    {
        $stored = ['v' => 1];
        $area = self::area($stored);
        $snapshots = Mockery::mock(SnapshotStore::class);
        $snapshots->shouldNotReceive('save');

        $result = (new DesignChange($snapshots, FakeChangeLog::forbidden()))->run(
            'lit/divi-presets-set',
            $area,
            ['confirm' => true, 'design_rev' => $area->rev($stored)],
            self::plan(['v' => 2], self::usages([3]))
        );

        $details = self::assertToolError($result, 'forbidden');
        self::assertSame([3], $details['blocked_ids']);
    }

    public function testConfirmTakesASnapshotWritesAndLogs(): void
    {
        $stored = ['v' => 1];
        $area = self::area($stored);
        $snapshots = Mockery::mock(SnapshotStore::class);
        $snapshots->expects('save')->with('presets', ['v' => 1], 'lit/divi-presets-set')->andReturn('presets-1');
        $snapshots->expects('attachLog')->with('presets', 'presets-1', 9);
        $log = new FakeChangeLog(9);

        $result = (new DesignChange($snapshots, $log))->run(
            'lit/divi-presets-set',
            $area,
            ['confirm' => true, 'design_rev' => $area->rev(['v' => 1])],
            self::plan(['v' => 2])
        );

        self::assertTrue($result['ok']);
        self::assertSame('presets-1', $result['snapshot_id']);
        self::assertSame(9, $result['log_id']);
        self::assertSame($area->rev(['v' => 2]), $result['design_rev']);
        self::assertSame(['v' => 2], $stored);
        self::assertSame('presets', $log->records[0]['object_id']);
        self::assertSame('divi_design', $log->records[0]['object_type']);
        self::assertSame('presets-1', $log->records[0]['snapshot_id']);
    }

    /** Final review I-3b: values Divi changed while saving are reported as warnings. */
    public function testValuesDiviChangedWhileSavingAreWarnings(): void
    {
        $stored = ['v' => 1];
        $area = self::area($stored, 0, true, ['Divi hat die Einstellungen von Preset „CTA“ beim Speichern bereinigt.']);
        $snapshots = Mockery::mock(SnapshotStore::class);
        $snapshots->expects('save')->andReturn('presets-1');
        $snapshots->expects('attachLog');

        $result = (new DesignChange($snapshots, new FakeChangeLog(9)))->run(
            'lit/divi-presets-set',
            $area,
            ['confirm' => true, 'design_rev' => $area->rev($stored)],
            self::plan(['v' => 2])
        );

        self::assertTrue($result['ok']);
        self::assertContains('Divi hat die Einstellungen von Preset „CTA“ beim Speichern bereinigt.', $result['warnings']);
    }

    public function testLockedDiviWritesNoSnapshot(): void
    {
        ReleaseGate::useResolver(static fn (): ReleaseStatus => new ReleaseStatus(ReleaseState::Untested, '5.16.0'));
        $stored = ['v' => 1];
        $area = self::area($stored);
        $snapshots = Mockery::mock(SnapshotStore::class);
        $snapshots->shouldNotReceive('save');

        $this->expectException(DiviLocked::class);

        (new DesignChange($snapshots, FakeChangeLog::forbidden()))->run(
            'lit/divi-presets-set',
            $area,
            ['confirm' => true, 'design_rev' => $area->rev($stored)],
            self::plan(['v' => 2])
        );
    }

    public function testTheLockFollowsTheFeatureOfTheArea(): void
    {
        $others = array_values(array_filter(
            DiviFeature::cases(),
            static fn (DiviFeature $feature): bool => $feature !== DiviFeature::PresetWrite
        ));
        ReleaseGate::useResolver(static fn (): ReleaseStatus => ReleaseMatrices::status($others));
        $stored = ['v' => 1];
        $area = self::area($stored);
        $snapshots = Mockery::mock(SnapshotStore::class);
        $snapshots->expects('save')->andReturn('s1');
        $snapshots->expects('attachLog');

        $written = (new DesignChange($snapshots, new FakeChangeLog(9)))->run(
            'lit/divi-presets-set',
            $area,
            ['confirm' => true, 'design_rev' => $area->rev($stored)],
            self::plan(['v' => 2])
        );
        self::assertTrue($written['ok'], 'every other feature locked: presets are still written');

        ReleaseGate::useResolver(static fn (): ReleaseStatus => ReleaseMatrices::status([DiviFeature::PresetWrite]));
        try {
            (new DesignChange(Mockery::mock(SnapshotStore::class), FakeChangeLog::forbidden()))->run(
                'lit/divi-presets-set',
                $area,
                ['confirm' => true, 'design_rev' => $area->rev($stored)],
                self::plan(['v' => 3])
            );
            self::fail('preset-write locked must refuse');
        } catch (DiviLocked $locked) {
            self::assertSame([DiviFeature::PresetWrite], $locked->features);
        }
    }

    public function testTooLargeSnapshotRefusesTheChange(): void
    {
        $stored = ['v' => 1];
        $area = self::area($stored);
        $snapshots = Mockery::mock(SnapshotStore::class);
        $snapshots->expects('save')->andThrow(new SnapshotTooLarge(3000000));

        $result = (new DesignChange($snapshots, FakeChangeLog::forbidden()))->run(
            'lit/divi-presets-set',
            $area,
            ['confirm' => true, 'design_rev' => $area->rev($stored)],
            self::plan(['v' => 2])
        );

        self::assertToolError($result, 'snapshot_too_large');
        self::assertSame([], $area->writes);
    }

    public function testFailedWriteRestoresTheSnapshot(): void
    {
        $stored = ['v' => 1];
        $area = self::area($stored, 1);
        $snapshots = Mockery::mock(SnapshotStore::class);
        $snapshots->expects('save')->andReturn('presets-1');

        try {
            (new DesignChange($snapshots, FakeChangeLog::forbidden()))->run(
                'lit/divi-presets-set',
                $area,
                ['confirm' => true, 'design_rev' => $area->rev($stored)],
                self::plan(['v' => 2])
            );
            self::fail('expected WriteFailed');
        } catch (WriteFailed $e) {
            self::assertTrue($e->rolledBack);
            self::assertSame('presets-1', $e->details['snapshot_id']);
        }

        self::assertSame([[['v' => 2], false]], $area->writes);
        self::assertSame([['v' => 1]], $area->restores, 'the rollback writes the snapshot back with restore()');
        self::assertSame(['v' => 1], $stored);
    }

    public function testReadBackMismatchRestoresTheSnapshot(): void
    {
        $stored = ['v' => 1];
        $area = self::area($stored, 0, false);
        $snapshots = Mockery::mock(SnapshotStore::class);
        $snapshots->expects('save')->andReturn('presets-1');

        $this->expectException(WriteFailed::class);

        (new DesignChange($snapshots, FakeChangeLog::forbidden()))->run(
            'lit/divi-presets-set',
            $area,
            ['confirm' => true, 'design_rev' => $area->rev($stored)],
            self::plan(['v' => 2])
        );
    }

    public function testFailedRollbackIsPartial(): void
    {
        $stored = ['v' => 1];
        $area = self::area($stored, 2);
        $snapshots = Mockery::mock(SnapshotStore::class);
        $snapshots->expects('save')->andReturn('presets-1');
        $log = FakeChangeLog::partialsOnly();

        try {
            (new DesignChange($snapshots, $log))->run(
                'lit/divi-presets-set',
                $area,
                ['confirm' => true, 'design_rev' => $area->rev($stored)],
                self::plan(['v' => 2])
            );
            self::fail('expected WriteFailed');
        } catch (WriteFailed $e) {
            self::assertFalse($e->rolledBack);
            self::assertStringContainsString('presets-1', (string) $e->hint);
        }

        self::assertCount(1, $log->partials);
    }
}