<?php
/**
 * Content Studio drafting: working copy, outline, sections, rewrite proposals.
 *
 * @package MazeAi
 * @since   0.1.4
 */

declare(strict_types=1);

namespace MazeAi\Http\Controllers;

defined('ABSPATH') || exit;

use Illuminate\MazeAssistant\Http\JsonResponse;
use Illuminate\MazeAssistant\Http\Request;
use MazeAi\Ai\ModelGateway;
use MazeAi\Chat\Transcript;
use MazeAi\Models\Session;
use MazeAi\Modules\ContentStudio\Models\StudioState;
use MazeAi\Modules\ContentStudio\Services\DraftingPrompts;
use MazeAi\Support\Redactor;

/**
 * The drafting side of Content Studio (decision 051). Nothing here writes to WordPress; the working copy, outline and
 * proposals are lines in the document's session.
 *
 * - `PUT /studios/content/documents/{id}/revision` `{title, excerpt, body, rev}`: autosave the working copy. 409 when `rev` is stale.
 * - `POST /studios/content/documents/{id}/outline` `{instruction?, model?, message_id?}`: ask for a new outline (a run).
 * - `PUT /studios/content/documents/{id}/outline` `{sections: [{key, heading, points}], approved?}`: the person's outline.
 * - `POST /studios/content/documents/{id}/sections/{key}` `{instruction?, message_id?}`: write one section (a run).
 * - `POST /studios/content/documents/{id}/proposal` `{action: accept|discard}`: settle a rewrite proposal.
 *
 * @since 0.1.4
 */
class StudioDraftController extends StudioRunController
{
    public function revise(Request $request): JsonResponse
    {
        $session = $this->open($request);
        if ($session instanceof JsonResponse) {
            return $session;
        }
        $document = $this->input($request);
        if (is_string($document)) {
            return $this->validationError(['body' => [$document]]);
        }
        $state = $this->state($session);
        if ($session->run_status === 'running') {
            return $this->error(__('The assistant is writing; wait for it to finish.', 'maze-graph'), 409);
        }
        if ((int) $request->input('rev', -1) !== $state['rev']) {
            return $this->error(__('A newer copy of this document exists. Reload to see it.', 'maze-graph'), 409, ['rev' => [(string) $state['rev']]]);
        }
        if ($state['working'] === $document) {
            return $this->noStore($this->ok(['rev' => $state['rev'], 'capped' => false]));
        }
        if ($state['rev'] >= StudioState::MAX_REVISIONS) {
            return $this->noStore($this->ok(['rev' => $state['rev'], 'capped' => true]));
        }
        $this->store->append($session->id, Transcript::event('studio_revision', $document));

        return $this->noStore($this->ok(['rev' => $state['rev'] + 1, 'capped' => false]));
    }

    public function outline(Request $request, ModelGateway $gateway): JsonResponse
    {
        $session = $this->open($request);
        if ($session instanceof JsonResponse) {
            return $session;
        }
        $instruction = Redactor::cleanText((string) $request->input('instruction', ''));
        if (mb_strlen($instruction) > 1000) {
            return $this->validationError(['instruction' => [__('Use at most 1,000 characters.', 'maze-graph')]]);
        }
        $refused = $this->refusal($gateway);
        if ($refused !== null) {
            return $refused;
        }
        $started = $this->runs->start($session->id, DraftingPrompts::lead($this->state($session), 'plan', true) . DraftingPrompts::newOutline($instruction), $this->userId(), $this->clientId($request));
        if ($started === null) {
            return $this->busy();
        }
        $this->store->append($session->id, Transcript::event('studio_expect', ['kind' => 'outline']));

        return $this->reply($session, $started);
    }

    public function saveOutline(Request $request): JsonResponse
    {
        $session = $this->open($request);
        if ($session instanceof JsonResponse) {
            return $session;
        }
        if ($session->run_status === 'running') {
            return $this->error(__('The assistant is writing; wait for it to finish.', 'maze-graph'), 409);
        }
        $sections = StudioState::cleanOutline(is_array($request->input('sections')) ? $request->input('sections') : []);
        if (is_string($sections)) {
            return $this->validationError(['sections' => [match ($sections) {
                'heading_too_long' => __('A heading can have at most 200 characters.', 'maze-graph'),
                'too_many'         => sprintf(
                    /* translators: %d: maximum number of sections. */
                    __('An outline can have at most %d sections.', 'maze-graph'),
                    StudioState::MAX_SECTIONS
                ),
                default            => __('Add at least one section with a heading.', 'maze-graph'),
            }]]);
        }
        $this->store->append($session->id, Transcript::event('studio_outline', ['sections' => $sections, 'approved' => $request->input('approved') === true]));

        return $this->noStore($this->ok($this->document($session)));
    }

    public function section(Request $request, ModelGateway $gateway): JsonResponse
    {
        $session = $this->open($request);
        if ($session instanceof JsonResponse) {
            return $session;
        }
        $state   = $this->state($session);
        $key     = (string) $request->route('key');
        $section = null;
        foreach ($state['outline']['sections'] ?? [] as $candidate) {
            if ($candidate['key'] === $key) {
                $section = $candidate;
            }
        }
        if ($section === null) {
            return $this->validationError(['key' => [__('That section is not in the outline.', 'maze-graph')]]);
        }
        $instruction = Redactor::cleanText((string) $request->input('instruction', ''));
        if (mb_strlen($instruction) > 500) {
            return $this->validationError(['instruction' => [__('Use at most 500 characters.', 'maze-graph')]]);
        }
        $refused = $this->refusal($gateway);
        if ($refused !== null) {
            return $refused;
        }
        $started = $this->runs->start($session->id, DraftingPrompts::lead($state, 'write', true) . DraftingPrompts::section($state['outline']['sections'], $section, $instruction), $this->userId(), $this->clientId($request));
        if ($started === null) {
            return $this->busy();
        }
        $this->store->append($session->id, Transcript::event('studio_expect', ['kind' => 'section', 'key' => $key, 'heading' => $section['heading']]));

        return $this->reply($session, $started);
    }

    public function resolve(Request $request): JsonResponse
    {
        $session = $this->open($request);
        if ($session instanceof JsonResponse) {
            return $session;
        }
        if ($session->run_status === 'running') {
            return $this->error(__('The assistant is writing; wait for it to finish.', 'maze-graph'), 409);
        }
        $action = (string) $request->input('action', '');
        if (!in_array($action, ['accept', 'discard'], true)) {
            return $this->validationError(['action' => [__('Choose accept or discard.', 'maze-graph')]]);
        }
        $state = $this->state($session);
        if ($state['proposal'] === null) {
            return $this->error(__('There is no rewrite waiting.', 'maze-graph'), 409);
        }
        $this->store->append($session->id, Transcript::event('studio_resolve', ['action' => $action]));
        if ($action === 'accept') {
            $this->store->append($session->id, Transcript::event('studio_revision', $state['proposal'] + ['source' => 'rewrite']));
        }

        return $this->noStore($this->ok($this->document($session)));
    }

    /**
     * The document's session, or the reply that says why not.
     */
    protected function open(Request $request): Session|JsonResponse
    {
        if (!$this->on()) {
            return $this->off();
        }

        return $this->session($request) ?? $this->missing();
    }
}