import { eq, inArray } from 'drizzle-orm';
import { db } from '@/db';
import { clients, projects, phases, tasks, deliverables, payments, documents, notes } from '@/db/schema';

/**
 * ClientView: The ONLY data shape returned to client-facing routes.
 * Deliberately excludes: quote_items, service_catalog, service prices, payment amounts.
 * Enforced server-side: client API never touches admin data.
 *
 * Architecture constraint (LOCKED): quote_items are admin-only.
 * accepted_total is the only price-related field returned to clients.
 */
export interface ClientView {
  client: {
    id: string;
    name: string;
    brand_name: string;
    brief: string;
    accepted_total: string; // only total, never breakdown
  };
  phases: Array<{
    id: string;
    title: string;
    status: 'upcoming' | 'active' | 'done';
    sort_order: number;
    tasks: Array<{
      id: string;
      title: string;
      description: string | null;
      status: 'todo' | 'in_progress' | 'done';
      sort_order: number;
      deliverables: Array<{
        id: string;
        title: string;
        url: string | null;
        status: 'pending' | 'submitted' | 'approved';
        approved_at: string | null; // ISO timestamp — immutable once set
      }>;
    }>;
    progress_pct: number; // % of tasks done in this phase
  }>;
  payments: Array<{
    id: string;
    label: string; // "Acconto 50%" | "Saldo 50%"
    status: 'da_saldare' | 'inviata' | 'saldato';
    // NOTE: amount is intentionally omitted — clients see only label and status
  }>;
  documents: Array<{
    id: string;
    label: string;
    url: string;
  }>;
  notes: Array<{
    id: string;
    body: string;
    created_at: string; // ISO timestamp
  }>;
  global_progress_pct: number; // % of all tasks done across all phases
}

/**
 * getClientView: Fetch all client data and return only the ClientView shape.
 * NEVER queries quote_items, service_catalog, or service prices.
 * Aggregates data across all projects for this client.
 */
export async function getClientView(token: string): Promise<ClientView | null> {
  // Fetch client by token (Architecture constraint: token is separate from id PK)
  const clientRow = await db
    .select()
    .from(clients)
    .where(eq(clients.token, token))
    .limit(1);

  if (clientRow.length === 0) {
    return null;
  }

  const client = clientRow[0];

  // Get all projects for this client (data is now project-scoped)
  const projectRows = await db
    .select({ id: projects.id })
    .from(projects)
    .where(eq(projects.client_id, client.id));
  const projectIds = projectRows.map((p) => p.id);

  if (projectIds.length === 0) {
    return {
      client: {
        id: client.id,
        name: client.name,
        brand_name: client.brand_name,
        brief: client.brief,
        accepted_total: client.accepted_total ?? '0',
      },
      phases: [],
      payments: [],
      documents: [],
      notes: [],
      global_progress_pct: 0,
    };
  }

  // Fetch all phases across all projects, ordered by sort_order
  const phasesRows = await db
    .select()
    .from(phases)
    .where(inArray(phases.project_id, projectIds))
    .orderBy(phases.sort_order);

  const phaseIds = phasesRows.map((p) => p.id);
  const tasksRows =
    phaseIds.length === 0
      ? []
      : await db
          .select()
          .from(tasks)
          .where(inArray(tasks.phase_id, phaseIds))
          .orderBy(tasks.sort_order);

  const taskIds = tasksRows.map((t) => t.id);
  const deliverablesRows =
    taskIds.length === 0
      ? []
      : await db
          .select()
          .from(deliverables)
          .where(inArray(deliverables.task_id, taskIds));

  // Fetch payments — label and status only, amount is intentionally excluded from ClientView
  const paymentsRows = await db
    .select()
    .from(payments)
    .where(inArray(payments.project_id, projectIds));

  const documentsRows = await db
    .select()
    .from(documents)
    .where(inArray(documents.project_id, projectIds));

  const notesRows = await db
    .select()
    .from(notes)
    .where(inArray(notes.project_id, projectIds))
    .orderBy(notes.created_at);

  // Build hierarchical structure: phases → tasks → deliverables
  const phasesList = phasesRows.map((phase) => {
    const phaseTasksRows = tasksRows.filter((t) => t.phase_id === phase.id);

    const tasksList = phaseTasksRows.map((task) => {
      const taskDeliverables = deliverablesRows
        .filter((d) => d.task_id === task.id)
        .map((d) => ({
          id: d.id,
          title: d.title,
          url: d.url,
          status: d.status as 'pending' | 'submitted' | 'approved',
          // approved_at is immutable once set (Architecture constraint LOCKED)
          approved_at: d.approved_at ? new Date(d.approved_at).toISOString() : null,
        }));

      return {
        id: task.id,
        title: task.title,
        description: task.description,
        status: task.status as 'todo' | 'in_progress' | 'done',
        sort_order: task.sort_order,
        deliverables: taskDeliverables,
      };
    });

    const taskCount = tasksList.length;
    const doneCount = tasksList.filter((t) => t.status === 'done').length;
    const progress_pct = taskCount === 0 ? 0 : Math.round((doneCount / taskCount) * 100);

    return {
      id: phase.id,
      title: phase.title,
      status: phase.status as 'upcoming' | 'active' | 'done',
      sort_order: phase.sort_order,
      tasks: tasksList,
      progress_pct,
    };
  });

  const allDoneCount = tasksRows.filter((t) => t.status === 'done').length;
  const globalProgressPct =
    tasksRows.length === 0 ? 0 : Math.round((allDoneCount / tasksRows.length) * 100);

  const paymentsList = paymentsRows.map((p) => ({
    id: p.id,
    label: p.label,
    status: p.status as 'da_saldare' | 'inviata' | 'saldato',
  }));

  const documentsList = documentsRows.map((d) => ({
    id: d.id,
    label: d.label,
    url: d.url,
  }));

  const notesList = notesRows.map((n) => ({
    id: n.id,
    body: n.body,
    created_at: new Date(n.created_at).toISOString(),
  }));

  return {
    client: {
      id: client.id,
      name: client.name,
      brand_name: client.brand_name,
      brief: client.brief,
      accepted_total: client.accepted_total ?? '0',
    },
    phases: phasesList,
    payments: paymentsList,
    documents: documentsList,
    notes: notesList,
    global_progress_pct: globalProgressPct,
  };
}