<?php

namespace App\Http\Controllers\Api\V1;

use Domains\Platform\Resources\PlatformChannelResource;
use Domains\Platform\Models\PlatformChannel;
use Domains\Platform\Models\PlatformAccount;
use Domains\Platform\Models\PlatformInstance;
use Domains\Platform\Services\ChannelLanguageDetectionService;
use Domains\Platform\Api\Lemmy\LemmyApiService;
use Domains\Platform\Exceptions\ChannelException;
use Illuminate\Http\JsonResponse;
use Illuminate\Http\Request;
use Illuminate\Validation\ValidationException;
use Illuminate\Support\Facades\Cache;

class PlatformChannelsController extends BaseController
{
    /**
     * Display a listing of platform channels
     */
    public function index(): JsonResponse
    {
        $channels = PlatformChannel::with(['platformInstance', 'platformAccounts'])
            ->orderBy('is_active', 'desc')
            ->orderBy('name')
            ->get();

        return $this->sendResponse(
            PlatformChannelResource::collection($channels),
            'Platform channels retrieved successfully.'
        );
    }

    /**
     * Store a newly created platform channel
     */
    public function store(Request $request): JsonResponse
    {
        try {
            $validated = $request->validate([
                'platform_instance_id' => 'required|exists:platform_instances,id',
                'channel_id' => 'required|string|max:255',
                'name' => 'required|string|max:255',
                'display_name' => 'nullable|string|max:255',
                'description' => 'nullable|string',
                'is_active' => 'boolean',
            ]);

            $validated['is_active'] = $validated['is_active'] ?? true;

            // Get the platform instance to check for active accounts
            $platformInstance = \Domains\Platform\Models\PlatformInstance::findOrFail($validated['platform_instance_id']);
            
            // Check if there are active platform accounts for this instance
            $activeAccounts = PlatformAccount::where('instance_url', $platformInstance->url)
                ->where('is_active', true)
                ->get();

            if ($activeAccounts->isEmpty()) {
                return $this->sendError(
                    'Cannot create channel: No active platform accounts found for this instance. Please create a platform account first.',
                    [],
                    422
                );
            }

            // Detect and validate channel languages
            $languageDetectionService = app(ChannelLanguageDetectionService::class);
            
            try {
                $languageInfo = $languageDetectionService->detectChannelLanguages(
                    $validated['name'], 
                    $validated['platform_instance_id']
                );
                
                // Add detected language to validated data
                $validated['language_id'] = $languageInfo['language_id'];
                
            } catch (ChannelException $e) {
                return $this->sendError($e->getMessage(), [], 422);
            }

            $channel = PlatformChannel::create($validated);

            // Automatically attach the first active account to the channel
            $firstAccount = $activeAccounts->first();
            $channel->platformAccounts()->attach($firstAccount->id, [
                'is_active' => true,
                'priority' => 1,
                'created_at' => now(),
                'updated_at' => now(),
            ]);

            $responseMessage = 'Platform channel created successfully and linked to platform account!';
            
            // Add information about language detection if fallback was used
            if (isset($languageInfo['fallback_used']) && $languageInfo['fallback_used']) {
                $responseMessage .= ' Note: Used default language due to detection issue.';
            }

            return $this->sendResponse(
                new PlatformChannelResource($channel->load(['platformInstance', 'platformAccounts', 'language'])),
                $responseMessage,
                201
            );
        } catch (ValidationException $e) {
            return $this->sendValidationError($e->errors());
        } catch (\Exception $e) {
            return $this->sendError('Failed to create platform channel: ' . $e->getMessage(), [], 500);
        }
    }

    /**
     * Display the specified platform channel
     */
    public function show(PlatformChannel $platformChannel): JsonResponse
    {
        return $this->sendResponse(
            new PlatformChannelResource($platformChannel->load('platformInstance')),
            'Platform channel retrieved successfully.'
        );
    }

    /**
     * Update the specified platform channel
     */
    public function update(Request $request, PlatformChannel $platformChannel): JsonResponse
    {
        try {
            $validated = $request->validate([
                'name' => 'required|string|max:255',
                'display_name' => 'nullable|string|max:255',
                'description' => 'nullable|string',
                'is_active' => 'boolean',
            ]);

            $platformChannel->update($validated);

            return $this->sendResponse(
                new PlatformChannelResource($platformChannel->fresh(['platformInstance'])),
                'Platform channel updated successfully!'
            );
        } catch (ValidationException $e) {
            return $this->sendValidationError($e->errors());
        } catch (\Exception $e) {
            return $this->sendError('Failed to update platform channel: ' . $e->getMessage(), [], 500);
        }
    }

    /**
     * Remove the specified platform channel
     */
    public function destroy(PlatformChannel $platformChannel): JsonResponse
    {
        try {
            $platformChannel->delete();

            return $this->sendResponse(
                null,
                'Platform channel deleted successfully!'
            );
        } catch (\Exception $e) {
            return $this->sendError('Failed to delete platform channel: ' . $e->getMessage(), [], 500);
        }
    }

    /**
     * Toggle platform channel active status
     */
    public function toggle(PlatformChannel $channel): JsonResponse
    {
        try {
            $newStatus = !$channel->is_active;
            $channel->update(['is_active' => $newStatus]);

            $status = $newStatus ? 'activated' : 'deactivated';

            return $this->sendResponse(
                new PlatformChannelResource($channel->fresh(['platformInstance', 'platformAccounts'])),
                "Platform channel {$status} successfully!"
            );
        } catch (\Exception $e) {
            return $this->sendError('Failed to toggle platform channel status: ' . $e->getMessage(), [], 500);
        }
    }

    /**
     * Attach a platform account to a channel
     */
    public function attachAccount(PlatformChannel $channel, Request $request): JsonResponse
    {
        try {
            $validated = $request->validate([
                'platform_account_id' => 'required|exists:platform_accounts,id',
                'is_active' => 'boolean',
                'priority' => 'nullable|integer|min:1|max:100',
            ]);

            $platformAccount = PlatformAccount::findOrFail($validated['platform_account_id']);

            // Check if account is already attached
            if ($channel->platformAccounts()->where('platform_account_id', $platformAccount->id)->exists()) {
                return $this->sendError('Platform account is already attached to this channel.', [], 422);
            }

            $channel->platformAccounts()->attach($platformAccount->id, [
                'is_active' => $validated['is_active'] ?? true,
                'priority' => $validated['priority'] ?? 1,
                'created_at' => now(),
                'updated_at' => now(),
            ]);

            return $this->sendResponse(
                new PlatformChannelResource($channel->fresh(['platformInstance', 'platformAccounts'])),
                'Platform account attached to channel successfully!'
            );
        } catch (ValidationException $e) {
            return $this->sendValidationError($e->errors());
        } catch (\Exception $e) {
            return $this->sendError('Failed to attach platform account: ' . $e->getMessage(), [], 500);
        }
    }

    /**
     * Detach a platform account from a channel
     */
    public function detachAccount(PlatformChannel $channel, PlatformAccount $account): JsonResponse
    {
        try {
            if (!$channel->platformAccounts()->where('platform_account_id', $account->id)->exists()) {
                return $this->sendError('Platform account is not attached to this channel.', [], 422);
            }

            $channel->platformAccounts()->detach($account->id);

            return $this->sendResponse(
                new PlatformChannelResource($channel->fresh(['platformInstance', 'platformAccounts'])),
                'Platform account detached from channel successfully!'
            );
        } catch (\Exception $e) {
            return $this->sendError('Failed to detach platform account: ' . $e->getMessage(), [], 500);
        }
    }

    /**
     * Update platform account-channel relationship settings
     */
    public function updateAccountRelation(PlatformChannel $channel, PlatformAccount $account, Request $request): JsonResponse
    {
        try {
            $validated = $request->validate([
                'is_active' => 'boolean',
                'priority' => 'nullable|integer|min:1|max:100',
            ]);

            if (!$channel->platformAccounts()->where('platform_account_id', $account->id)->exists()) {
                return $this->sendError('Platform account is not attached to this channel.', [], 422);
            }

            $channel->platformAccounts()->updateExistingPivot($account->id, [
                'is_active' => $validated['is_active'] ?? true,
                'priority' => $validated['priority'] ?? 1,
                'updated_at' => now(),
            ]);

            return $this->sendResponse(
                new PlatformChannelResource($channel->fresh(['platformInstance', 'platformAccounts'])),
                'Platform account-channel relationship updated successfully!'
            );
        } catch (ValidationException $e) {
            return $this->sendValidationError($e->errors());
        } catch (\Exception $e) {
            return $this->sendError('Failed to update platform account relationship: ' . $e->getMessage(), [], 500);
        }
    }

    /**
     * Get available communities for a platform instance
     */
    public function getCommunities(Request $request): JsonResponse
    {
        try {
            $validated = $request->validate([
                'platform_instance_id' => 'required|exists:platform_instances,id',
                'type' => 'sometimes|string|in:Local,All,Subscribed',
                'sort' => 'sometimes|string|in:Hot,Active,New,TopDay,TopWeek,TopMonth,TopYear,TopAll',
                'limit' => 'sometimes|integer|min:1|max:100',
                'page' => 'sometimes|integer|min:1',
                'show_nsfw' => 'sometimes|boolean',
            ]);

            $platformInstance = PlatformInstance::findOrFail($validated['platform_instance_id']);

            // Check if there are active platform accounts for this instance to get auth token
            $activeAccount = PlatformAccount::where('instance_url', $platformInstance->url)
                ->where('is_active', true)
                ->first();

            if (!$activeAccount) {
                return $this->sendError(
                    'Cannot fetch communities: No active platform accounts found for this instance. Please create a platform account first.',
                    [],
                    422
                );
            }

            // Create cache key based on instance and parameters
            $cacheKey = sprintf(
                'communities:%s:%s:%s:%d:%d:%s',
                $platformInstance->id,
                $validated['type'] ?? 'Local',
                $validated['sort'] ?? 'Active',
                $validated['limit'] ?? 50,
                $validated['page'] ?? 1,
                $validated['show_nsfw'] ?? false ? '1' : '0'
            );

            // Try to get communities from cache first (cache for 10 minutes)
            $communities = Cache::remember($cacheKey, 600, function () use ($platformInstance, $activeAccount, $validated) {
                $apiService = app(LemmyApiService::class, ['instance' => $platformInstance->url]);
                
                return $apiService->listCommunities(
                    $activeAccount->settings['api_token'] ?? null,
                    $validated['type'] ?? 'Local',
                    $validated['sort'] ?? 'Active',
                    $validated['limit'] ?? 50,
                    $validated['page'] ?? 1,
                    $validated['show_nsfw'] ?? false
                );
            });

            // Transform the response to include only relevant data and add helpful fields
            $transformedCommunities = collect($communities['communities'] ?? [])->map(function ($item) {
                $community = $item['community'] ?? [];
                return [
                    'id' => $community['id'] ?? null,
                    'name' => $community['name'] ?? null,
                    'title' => $community['title'] ?? null,
                    'description' => $community['description'] ?? null,
                    'nsfw' => $community['nsfw'] ?? false,
                    'local' => $community['local'] ?? false,
                    'subscribers' => $item['counts']['subscribers'] ?? 0,
                    'posts' => $item['counts']['posts'] ?? 0,
                    'display_text' => sprintf(
                        '%s (%s subscribers)',
                        $community['title'] ?? $community['name'] ?? 'Unknown',
                        number_format($item['counts']['subscribers'] ?? 0)
                    ),
                ];
            });

            return $this->sendResponse([
                'communities' => $transformedCommunities,
                'total' => $transformedCommunities->count(),
                'platform_instance' => [
                    'id' => $platformInstance->id,
                    'name' => $platformInstance->name,
                    'url' => $platformInstance->url,
                ],
                'parameters' => [
                    'type' => $validated['type'] ?? 'Local',
                    'sort' => $validated['sort'] ?? 'Active',
                    'limit' => $validated['limit'] ?? 50,
                    'page' => $validated['page'] ?? 1,
                    'show_nsfw' => $validated['show_nsfw'] ?? false,
                ]
            ], 'Communities retrieved successfully.');

        } catch (ValidationException $e) {
            return $this->sendValidationError($e->errors());
        } catch (\Exception $e) {
            // Clear cache on error to prevent serving stale data
            if (isset($cacheKey)) {
                Cache::forget($cacheKey);
            }
            
            return $this->sendError('Failed to fetch communities: ' . $e->getMessage(), [], 500);
        }
    }
}