<?php

namespace App\Services;

use App\Models\Setting;
use Illuminate\Support\Facades\Schema;

class AppSettingsService
{
    public function defaults(): array
    {
        return [
            'tone_addressing' => 'je',
            'prompt.normalization' => 'You rewrite customer support questions. Keep intent, fix spelling, remove noise, redact PII. Return JSON with normalized_message and redaction_report.',
            'prompt.classifier' => 'You are a support assistant. Select best article and return JSON. Include tool_call only when the selected article explicitly allows that action and all required parameters are present.',
            'prompt.knowledge_gap' => 'Create a draft knowledge base article suggestion based on the customer question. Use the requested output language passed in the prompt. Return JSON only with keys: title, content.',
            'prompt.support_reply' => 'Give only direct advice in the requested output language. No greeting, no closing, no thank-you text. Start directly with the solution. Give 3-6 numbered action points and end with a verification step.',
            'llm.provider' => (string) config('services.llm.provider', 'ollama'),
            'llm.active_instance_id' => (string) config('services.llm.provider', 'ollama').'_default',
            'llm.provider_instances' => json_encode($this->defaultProviderInstances()),
            'llm.timeout' => (string) config('services.llm.timeout', 30),
            'llm.providers.ollama.base_url' => (string) config('services.llm.base_url', 'http://localhost:11434'),
            'llm.providers.ollama.chat_model' => (string) config('services.llm.chat_model', 'llama3'),
            'llm.providers.ollama.embedding_model' => (string) config('services.llm.embedding_model', 'nomic-embed-text'),
            'llm.providers.lmstudio.base_url' => (string) config('services.llm.base_url', 'http://localhost:1234'),
            'llm.providers.lmstudio.chat_model' => (string) config('services.llm.chat_model', 'local-model'),
            'llm.providers.lmstudio.embedding_model' => (string) config('services.llm.embedding_model', 'text-embedding-nomic-embed-text-v1.5@q6_k'),
            'llm.models.normalization' => (string) config('services.llm.chat_model', 'llama3'),
            'llm.models.classifier' => (string) config('services.llm.chat_model', 'llama3'),
            'llm.models.knowledge_gap' => (string) config('services.llm.chat_model', 'llama3'),
            'llm.models.support_reply' => (string) config('services.llm.chat_model', 'llama3'),
            'llm.models.embedding' => (string) config('services.llm.embedding_model', 'nomic-embed-text'),
        ];
    }

    public function processSteps(): array
    {
        return [
            ['id' => 'normalization', 'number' => 1, 'title' => 'Vraag netjes maken', 'description' => 'Haalt typefouten, ruis en privegegevens uit de klantvraag voordat de app ermee verder werkt.', 'prompt_key' => 'prompt.normalization'],
            ['id' => 'embedding', 'number' => 2, 'title' => 'Betekenis-code maken', 'description' => 'Zet de opgeschoonde vraag om naar een code die beschrijft waar de vraag over gaat.'],
            ['id' => 'retrieval', 'number' => 3, 'title' => 'Kennisbank zoeken', 'description' => 'Zoekt kleine stukjes kennisbanktekst die qua betekenis het meest op de vraag lijken.'],
            ['id' => 'classifier', 'number' => 4, 'title' => 'Beste artikel kiezen', 'description' => 'Laat de AI kiezen welk gevonden artikel het beste past en waarom.', 'prompt_key' => 'prompt.classifier'],
            ['id' => 'tool_call', 'number' => 5, 'title' => 'Extra informatie ophalen', 'description' => 'Gebruikt alleen toegestane hulpmiddelen, zoals domeininformatie ophalen, als het artikel dit toestaat.'],
            ['id' => 'quick_reply', 'number' => 6, 'title' => 'Snelantwoord controleren', 'description' => 'Gebruikt een gekoppeld snelantwoord als dat beschikbaar is, zodat de AI geen nieuw antwoord hoeft te schrijven.'],
            ['id' => 'knowledge_gap', 'number' => 7, 'title' => 'Missend artikel herkennen', 'description' => 'Geeft aan dat de kennisbank waarschijnlijk geen goed artikel heeft voor deze vraag.', 'prompt_key' => 'prompt.knowledge_gap'],
            ['id' => 'support_reply', 'number' => 8, 'title' => 'Conceptadvies maken', 'description' => 'Schrijft alleen een korte conceptreactie als er geen snelantwoord beschikbaar is.', 'prompt_key' => 'prompt.support_reply'],
        ];
    }

    public function providerDefinitions(): array
    {
        return [
            'lmstudio' => ['label' => 'LM Studio', 'description' => 'OpenAI-compatible endpoint op je lokale netwerk.'],
            'ollama' => ['label' => 'Ollama', 'description' => 'Lokale Ollama API zonder externe providers.'],
        ];
    }

    public function defaultProviderInstances(): array
    {
        return [
            [
                'id' => 'lmstudio_default',
                'name' => 'LM Studio',
                'type' => 'lmstudio',
                'base_url' => (string) config('services.llm.base_url', 'http://localhost:1234'),
                'chat_model' => (string) config('services.llm.chat_model', 'local-model'),
                'embedding_model' => (string) config('services.llm.embedding_model', 'text-embedding-nomic-embed-text-v1.5@q6_k'),
            ],
            [
                'id' => 'ollama_default',
                'name' => 'Ollama',
                'type' => 'ollama',
                'base_url' => (string) config('services.llm.base_url', 'http://localhost:11434'),
                'chat_model' => (string) config('services.llm.chat_model', 'llama3'),
                'embedding_model' => (string) config('services.llm.embedding_model', 'nomic-embed-text'),
            ],
        ];
    }

    public function modelTasks(): array
    {
        return [
            ['id' => 'normalization', 'number' => 1, 'title' => 'Vraag netjes maken', 'description' => 'Model dat de ruwe klantvraag herschrijft en privegegevens weghaalt.'],
            ['id' => 'embedding', 'number' => 2, 'title' => 'Betekenis-code maken', 'description' => 'Model dat vragen en artikelstukjes omzet naar zoekcodes.'],
            ['id' => 'classifier', 'number' => 3, 'title' => 'Beste artikel kiezen', 'description' => 'Model dat kiest welk artikel het beste past en hoe zeker die keuze is.'],
            ['id' => 'knowledge_gap', 'number' => 4, 'title' => 'Missend artikel herkennen', 'description' => 'Model dat een voorstel maakt als de kennisbank tekortschiet.'],
            ['id' => 'support_reply', 'number' => 5, 'title' => 'Conceptadvies maken', 'description' => 'Model dat het uiteindelijke advies opstelt.'],
        ];
    }

    public function all(): array
    {
        $this->ensureDefaultsPersisted();

        $defaults = $this->defaults();
        $stored = Setting::query()->pluck('value', 'key')->toArray();

        return array_merge($defaults, $stored);
    }

    public function get(string $key, ?string $default = null): ?string
    {
        $all = $this->all();

        return $all[$key] ?? $default;
    }

    public function getPrompt(string $key, ?string $default = null): ?string
    {
        $promptValue = $this->get('prompt.'.$key);
        if (is_string($promptValue) && trim($promptValue) !== '') {
            return $promptValue;
        }

        // Backward compatibility for earlier stored keys.
        $legacyKeyMap = [
            'normalization' => 'normalization_prompt',
            'classifier' => 'classifier_prompt',
            'support_reply' => 'support_reply_prompt',
        ];

        $legacyKey = $legacyKeyMap[$key] ?? null;
        if ($legacyKey !== null) {
            $legacyValue = $this->get($legacyKey);
            if (is_string($legacyValue) && trim($legacyValue) !== '') {
                return $legacyValue;
            }
        }

        return $default;
    }

    public function toneAddressing(): string
    {
        return $this->get('tone_addressing', 'je') === 'u' ? 'u' : 'je';
    }

    public function toneInstruction(): string
    {
        if ($this->toneAddressing() === 'u') {
            return 'Als de klanttaal Nederlands is: spreek de klant consequent formeel aan met u/uw. Gebruik geen je/jij/jouw.';
        }

        return 'Als de klanttaal Nederlands is: spreek de klant consequent informeel aan met je/jij/jouw. Gebruik geen u/uw.';
    }

    public function promptSettings(): array
    {
        $settings = $this->all();
        $prompts = [];

        foreach ($settings as $key => $value) {
            if (str_starts_with((string) $key, 'prompt.')) {
                $prompts[$key] = (string) $value;
            }
        }

        ksort($prompts);

        return $prompts;
    }

    public function promptValues(): array
    {
        $values = [];
        foreach ($this->processSteps() as $step) {
            if (isset($step['prompt_key'])) {
                $id = (string) $step['id'];
                $values[$id] = (string) $this->getPrompt($id, '');
            }
        }

        return $values;
    }

    public function providerSettings(): array
    {
        return [
            'instances' => $this->providerInstances(),
            'active_instance_id' => $this->activeProviderInstanceId(),
        ];
    }

    public function providerInstances(): array
    {
        $raw = $this->get('llm.provider_instances');
        $decoded = is_string($raw) ? json_decode($raw, true) : null;

        if (! is_array($decoded) || $decoded === []) {
            return $this->defaultProviderInstances();
        }

        return array_values(array_filter($decoded, static fn ($item) => is_array($item) && isset($item['id'], $item['type'])));
    }

    public function activeProviderInstanceId(): string
    {
        $active = (string) $this->get('llm.active_instance_id', '');
        $ids = array_column($this->providerInstances(), 'id');

        if ($active !== '' && in_array($active, $ids, true)) {
            return $active;
        }

        return (string) ($ids[0] ?? 'ollama_default');
    }

    public function activeProviderInstance(): array
    {
        $active = $this->activeProviderInstanceId();

        foreach ($this->providerInstances() as $instance) {
            if (($instance['id'] ?? null) === $active) {
                return $instance;
            }
        }

        return $this->defaultProviderInstances()[0];
    }

    public function modelSettings(): array
    {
        $models = [];
        foreach ($this->modelTasks() as $task) {
            $id = (string) $task['id'];
            $models[$id] = (string) $this->get("llm.models.{$id}", '');
        }

        return $models;
    }

    public function setMany(array $pairs): void
    {
        foreach ($pairs as $key => $value) {
            Setting::query()->updateOrCreate(['key' => $key], ['value' => (string) $value]);
        }
    }

    public function savePromptSettings(array $prompts): void
    {
        $keys = array_map(static fn ($key) => (string) $key, array_keys($prompts));
        Setting::query()
            ->where('key', 'like', 'prompt.%')
            ->whereNotIn('key', $keys)
            ->delete();

        foreach ($prompts as $key => $value) {
            Setting::query()->updateOrCreate(['key' => (string) $key], ['value' => (string) $value]);
        }
    }

    public function saveStructuredSettings(array $promptValues, array $providerInstances, string $activeProviderInstanceId, array $modelValues, int $timeout, string $tone): void
    {
        $activeInstance = collect($providerInstances)->firstWhere('id', $activeProviderInstanceId) ?: ($providerInstances[0] ?? []);
        $activeProvider = (string) ($activeInstance['type'] ?? 'ollama');

        $pairs = [
            'tone_addressing' => $tone,
            'llm.provider' => $activeProvider,
            'llm.active_instance_id' => $activeProviderInstanceId,
            'llm.provider_instances' => json_encode(array_values($providerInstances), JSON_UNESCAPED_SLASHES),
            'llm.timeout' => (string) $timeout,
        ];

        foreach ($promptValues as $id => $value) {
            $pairs['prompt.'.$id] = (string) $value;
        }

        foreach ($providerInstances as $instance) {
            $provider = (string) ($instance['type'] ?? '');
            if ($provider === '') {
                continue;
            }

            foreach (['base_url', 'chat_model', 'embedding_model'] as $field) {
                $pairs["llm.providers.{$provider}.{$field}"] = (string) ($instance[$field] ?? '');
            }
        }

        foreach ($modelValues as $id => $value) {
            $pairs["llm.models.{$id}"] = (string) $value;
        }

        $this->setMany($pairs);
    }

    private function ensureDefaultsPersisted(): void
    {
        if (! Schema::hasTable('settings')) {
            return;
        }

        foreach ($this->defaults() as $key => $value) {
            Setting::query()->firstOrCreate(['key' => $key], ['value' => (string) $value]);
        }
    }
}