<?php

declare(strict_types=1);

namespace App\Repositories;

use Core\Database;

class ProjectRepository
{
    public function __construct(protected ?Database $database = null)
    {
        $this->database ??= database();
    }

    public function dashboardSummary(): array
    {
        $projectCount = (int) ($this->database->first('SELECT COUNT(*) AS total FROM projects')['total'] ?? 0);
        $activeProjects = (int) ($this->database->first(
            'SELECT COUNT(*) AS total FROM projects WHERE status IN ("active", "at-risk")'
        )['total'] ?? 0);
        $openTasks = (int) ($this->database->first(
            'SELECT COUNT(*) AS total FROM tasks WHERE status != "done"'
        )['total'] ?? 0);
        $blockedTasks = (int) ($this->database->first(
            'SELECT COUNT(*) AS total FROM tasks WHERE status = "blocked"'
        )['total'] ?? 0);
        $dueSoonTasks = (int) ($this->database->first(
            'SELECT COUNT(*) AS total FROM tasks WHERE status != "done" AND due_date IS NOT NULL AND date(due_date) BETWEEN date("now") AND date("now", "+7 day")'
        )['total'] ?? 0);
        $overdueTasks = (int) ($this->database->first(
            'SELECT COUNT(*) AS total FROM tasks WHERE status != "done" AND due_date IS NOT NULL AND date(due_date) < date("now")'
        )['total'] ?? 0);

        return [
            'project_count' => $projectCount,
            'active_projects' => $activeProjects,
            'open_tasks' => $openTasks,
            'blocked_tasks' => $blockedTasks,
            'due_soon_tasks' => $dueSoonTasks,
            'overdue_tasks' => $overdueTasks,
        ];
    }

    public function recent(int $limit = 6): array
    {
        $limit = max(1, min(25, $limit));

        $rows = $this->database->query(
            'SELECT p.*, 
                    COUNT(t.id) AS task_count,
                    SUM(CASE WHEN t.status = "done" THEN 1 ELSE 0 END) AS done_task_count,
                    SUM(CASE WHEN t.status = "blocked" THEN 1 ELSE 0 END) AS blocked_task_count,
                    SUM(CASE WHEN t.status != "done" AND t.due_date IS NOT NULL AND date(t.due_date) < date("now") THEN 1 ELSE 0 END) AS overdue_task_count,
                    MAX(t.updated_at) AS latest_task_update
             FROM projects p
             LEFT JOIN tasks t ON t.project_id = p.id
             GROUP BY p.id
             ORDER BY CASE p.status WHEN "active" THEN 0 WHEN "at-risk" THEN 1 WHEN "planned" THEN 2 WHEN "paused" THEN 3 WHEN "done" THEN 4 ELSE 5 END,
                      p.updated_at DESC,
                      p.id DESC
             LIMIT ' . $limit
        );

        return array_map([$this, 'decorateProjectRow'], $rows);
    }

    public function all(string $search = '', string $status = ''): array
    {
        $where = [];
        $params = [];

        if ($search !== '') {
            $where[] = '(p.name LIKE :search OR p.code LIKE :search OR p.client_name LIKE :search OR p.description LIKE :search)';
            $params['search'] = '%' . $search . '%';
        }

        if ($status !== '') {
            $where[] = 'p.status = :status';
            $params['status'] = $status;
        }

        $sql = 'SELECT p.*, 
                       COUNT(t.id) AS task_count,
                       SUM(CASE WHEN t.status = "done" THEN 1 ELSE 0 END) AS done_task_count,
                       SUM(CASE WHEN t.status = "blocked" THEN 1 ELSE 0 END) AS blocked_task_count,
                       SUM(CASE WHEN t.status != "done" AND t.due_date IS NOT NULL AND date(t.due_date) < date("now") THEN 1 ELSE 0 END) AS overdue_task_count,
                       MAX(t.updated_at) AS latest_task_update
                FROM projects p
                LEFT JOIN tasks t ON t.project_id = p.id';

        if ($where !== []) {
            $sql .= ' WHERE ' . implode(' AND ', $where);
        }

        $sql .= ' GROUP BY p.id
                  ORDER BY CASE p.status WHEN "active" THEN 0 WHEN "at-risk" THEN 1 WHEN "planned" THEN 2 WHEN "paused" THEN 3 WHEN "done" THEN 4 ELSE 5 END,
                           COALESCE(p.due_date, "9999-12-31") ASC,
                           p.updated_at DESC,
                           p.id DESC';

        return array_map(
            [$this, 'decorateProjectRow'],
            $this->database->query($sql, $params)
        );
    }

    public function find(int $projectId): ?array
    {
        $project = $this->database->first(
            'SELECT p.*,
                    COUNT(t.id) AS task_count,
                    SUM(CASE WHEN t.status = "done" THEN 1 ELSE 0 END) AS done_task_count,
                    SUM(CASE WHEN t.status = "blocked" THEN 1 ELSE 0 END) AS blocked_task_count,
                    SUM(CASE WHEN t.status != "done" AND t.due_date IS NOT NULL AND date(t.due_date) < date("now") THEN 1 ELSE 0 END) AS overdue_task_count,
                    MAX(t.updated_at) AS latest_task_update
             FROM projects p
             LEFT JOIN tasks t ON t.project_id = p.id
             WHERE p.id = :id
             GROUP BY p.id',
            ['id' => $projectId]
        );

        if ($project === null) {
            return null;
        }

        return $this->decorateProjectDetail($project);
    }

    public function findBoard(int $projectId): ?array
    {
        $project = $this->find($projectId);

        if ($project === null) {
            return null;
        }

        $tasks = $this->database->query(
            'SELECT * FROM tasks WHERE project_id = :project_id ORDER BY
                CASE status
                    WHEN "backlog" THEN 0
                    WHEN "in-progress" THEN 1
                    WHEN "review" THEN 2
                    WHEN "blocked" THEN 3
                    WHEN "done" THEN 4
                    ELSE 5
                END,
                CASE priority
                    WHEN "urgent" THEN 0
                    WHEN "high" THEN 1
                    WHEN "normal" THEN 2
                    ELSE 3
                END,
                due_date IS NULL,
                due_date ASC,
                position ASC,
                id ASC',
            ['project_id' => $projectId]
        );

        $buckets = [
            'backlog' => [],
            'in-progress' => [],
            'review' => [],
            'blocked' => [],
            'done' => [],
        ];

        foreach ($tasks as $task) {
            $task['is_overdue'] = $task['status'] !== 'done' && !empty($task['due_date']) && strtotime((string) $task['due_date']) < strtotime(date('Y-m-d'));
            $task['priority_label'] = ucfirst(str_replace('-', ' ', $task['priority']));
            $task['status_label'] = task_status_label($task['status']);
            $task['status_class'] = status_class($task['status']);
            $bucketKey = array_key_exists($task['status'], $buckets) ? $task['status'] : 'backlog';
            $buckets[$bucketKey][] = $task;
        }

        $members = $this->database->query(
            'SELECT * FROM project_members WHERE project_id = :project_id ORDER BY is_primary DESC, id ASC',
            ['project_id' => $projectId]
        );

        $project['members'] = $members;
        $project['task_buckets'] = $buckets;
        $project['tasks'] = $tasks;
        $project['progress_percent'] = $this->progressPercentage($projectId, (int) $project['task_count'], (int) $project['done_task_count']);
        $project['throughput'] = $this->throughputLabel((int) $project['done_task_count'], (int) $project['task_count']);
        $project['health_class'] = $this->healthClass((string) $project['status'], (int) $project['overdue_task_count']);
        $project['latest_activity'] = $this->database->first(
            'SELECT created_at FROM activity_log WHERE project_id = :project_id ORDER BY created_at DESC, id DESC LIMIT 1',
            ['project_id' => $projectId]
        )['created_at'] ?? null;

        return $project;
    }

    public function create(array $data): int
    {
        $code = $data['code'] !== '' ? strtoupper($data['code']) : $this->generateProjectCode($data['name']);
        $code = $this->ensureUniqueCode($code);

        $this->database->execute(
            'INSERT INTO projects (
                code, name, client_name, description, status, start_date, due_date, budget_cents, owner_name, color_token
             ) VALUES (
                :code, :name, :client_name, :description, :status, :start_date, :due_date, :budget_cents, :owner_name, :color_token
             )',
            [
                'code' => $code,
                'name' => $data['name'],
                'client_name' => $data['client_name'] ?? '',
                'description' => $data['description'] ?? '',
                'status' => $data['status'] ?? 'planned',
                'start_date' => $data['start_date'] ?? null,
                'due_date' => $data['due_date'] ?? null,
                'budget_cents' => $data['budget_cents'] ?? 0,
                'owner_name' => $data['owner_name'] ?? '',
                'color_token' => $data['color_token'] ?? 'teal',
            ]
        );

        $projectId = (int) $this->database->pdo()->lastInsertId();

        if (!empty($data['members']) && is_array($data['members'])) {
            $this->saveMembers($projectId, $data['members']);
        }

        (new ActivityRepository($this->database))->record(
            'project_created',
            'Created project ' . $data['name'],
            trim((($data['client_name'] ?? '') !== '' ? 'Client: ' . $data['client_name'] : '') . (($data['description'] ?? '') !== '' ? ' ' . ($data['description'] ?? '') : '')),
            $projectId,
            null
        );

        return $projectId;
    }

    public function updateStatus(int $projectId, string $status): bool
    {
        $project = $this->database->first('SELECT id, name, status FROM projects WHERE id = :id', ['id' => $projectId]);

        if ($project === null) {
            return false;
        }

        $this->database->execute(
            'UPDATE projects SET status = :status, updated_at = CURRENT_TIMESTAMP WHERE id = :id',
            [
                'status' => $status,
                'id' => $projectId,
            ]
        );

        (new ActivityRepository($this->database))->record(
            'project_status_changed',
            'Project moved to ' . project_status_label($status),
            'Project status updated from ' . project_status_label($project['status']) . ' to ' . project_status_label($status) . '.',
            $projectId,
            null
        );

        return true;
    }

    protected function decorateProjectRow(array $row): array
    {
        $row['task_count'] = (int) ($row['task_count'] ?? 0);
        $row['done_task_count'] = (int) ($row['done_task_count'] ?? 0);
        $row['blocked_task_count'] = (int) ($row['blocked_task_count'] ?? 0);
        $row['overdue_task_count'] = (int) ($row['overdue_task_count'] ?? 0);
        $row['progress_percent'] = $this->progressPercentage((int) $row['id'], $row['task_count'], $row['done_task_count']);
        $row['health_class'] = $this->healthClass((string) $row['status'], $row['overdue_task_count']);
        $row['status_label'] = project_status_label((string) $row['status']);
        $row['budget_label'] = money_cents((int) ($row['budget_cents'] ?? 0));
        $row['task_traffic'] = $this->throughputLabel($row['done_task_count'], $row['task_count']);
        $row['due_label'] = format_date($row['due_date'] ?? null);
        $row['start_label'] = format_date($row['start_date'] ?? null);

        return $row;
    }

    protected function decorateProjectDetail(array $project): array
    {
        $project = $this->decorateProjectRow($project);
        $project['member_count'] = (int) ($this->database->first(
            'SELECT COUNT(*) AS total FROM project_members WHERE project_id = :project_id',
            ['project_id' => $project['id']]
        )['total'] ?? 0);

        return $project;
    }

    protected function saveMembers(int $projectId, array $members): void
    {
        $statement = $this->database->pdo()->prepare(
            'INSERT INTO project_members (project_id, full_name, role, allocation_percent, is_primary) VALUES (:project_id, :full_name, :role, :allocation_percent, :is_primary)'
        );

        foreach ($members as $index => $member) {
            $name = trim((string) ($member['full_name'] ?? ''));
            if ($name === '') {
                continue;
            }

            $statement->execute([
                'project_id' => $projectId,
                'full_name' => $name,
                'role' => trim((string) ($member['role'] ?? 'Contributor')),
                'allocation_percent' => max(0, min(100, (int) ($member['allocation_percent'] ?? 0))),
                'is_primary' => $index === 0 ? 1 : 0,
            ]);
        }
    }

    protected function generateProjectCode(string $name): string
    {
        $slug = strtoupper(preg_replace('/[^A-Za-z0-9]+/', '', $name) ?? 'PROJECT');
        $slug = substr($slug, 0, 6) ?: 'PROJECT';

        return 'PRJ-' . $slug . '-' . date('ym');
    }

    protected function ensureUniqueCode(string $code): string
    {
        $candidate = $code;
        $suffix = 2;

        while ($this->database->first('SELECT id FROM projects WHERE code = :code', ['code' => $candidate]) !== null) {
            $candidate = $code . '-' . $suffix;
            $suffix++;
        }

        return $candidate;
    }

    protected function progressPercentage(int $projectId, ?int $taskCount = null, ?int $doneCount = null): int
    {
        $taskCount ??= (int) ($this->database->first('SELECT COUNT(*) AS total FROM tasks WHERE project_id = :project_id', ['project_id' => $projectId])['total'] ?? 0);
        $doneCount ??= (int) ($this->database->first('SELECT COUNT(*) AS total FROM tasks WHERE project_id = :project_id AND status = "done"', ['project_id' => $projectId])['total'] ?? 0);

        if ($taskCount <= 0) {
            return 0;
        }

        return (int) round(($doneCount / $taskCount) * 100);
    }

    protected function throughputLabel(int $doneCount, int $taskCount): string
    {
        if ($taskCount === 0) {
            return 'No tasks yet';
        }

        if ($doneCount === 0) {
            return 'Starting up';
        }

        if ($doneCount >= $taskCount) {
            return 'Ready to ship';
        }

        return $doneCount . '/' . $taskCount . ' completed';
    }

    protected function healthClass(string $status, int $overdueTasks): string
    {
        if ($status === 'done') {
            return 'is-green';
        }

        if ($overdueTasks > 0 || $status === 'at-risk') {
            return 'is-red';
        }

        if ($status === 'paused') {
            return 'is-slate';
        }

        return 'is-blue';
    }
}