import { Hono } from 'hono';
import { HTTPException } from 'hono/http-exception';
import type { Db } from '../db/index.ts';
import { tickets, transactions, customFieldValues, customFields, queues, lifecycles } from '../db/schema.ts';
import { eq, asc } from 'drizzle-orm';
import { CreateTicketSchema, UpdateTicketSchema } from '../models/ticket.ts';
import { ScripEngine } from '../scrip/engine.ts';
import { LifecycleValidator } from '../lifecycle/validator.ts';
import type { LifecycleDefinition } from '../lifecycle/validator.ts';

export function createTicketsRouter(db: Db): Hono {
  const router = new Hono();
  const scripEngine = new ScripEngine(db);
  const lifecycleValidator = new LifecycleValidator();

  // GET / — list tickets
  router.get('/', async (c) => {
    const queueId = c.req.query('queue_id');
    const status = c.req.query('status');

    const result = await db.query.tickets.findMany({
      where: (t, { and, eq }) => {
        const conditions = [];
        if (queueId) conditions.push(eq(t.queue_id, queueId));
        if (status) conditions.push(eq(t.status, status));
        return conditions.length > 0 ? and(...conditions) : undefined;
      },
      orderBy: asc(tickets.created_at),
    });

    return c.json(result);
  });

  // POST / — create ticket
  router.post('/', async (c) => {
    const body = await c.req.json();
    const parsed = CreateTicketSchema.parse(body);

    const [ticket] = await db.insert(tickets).values({
      subject: parsed.subject,
      queue_id: parsed.queue_id,
      status: 'new',
      creator_id: '00000000-0000-0000-0000-000000000000',
    }).returning();

    if (!ticket) {
      throw new HTTPException(500, { message: 'Failed to create ticket' });
    }

    // Record transaction
    await db.insert(transactions).values({
      ticket_id: ticket.id,
      transaction_type: 'Create',
      field: 'status',
      new_value: 'new',
      creator_id: '00000000-0000-0000-0000-000000000000',
    });

    return c.json(ticket, 201);
  });

  // GET /:id — get ticket with custom field values
  router.get('/:id', async (c) => {
    const id = c.req.param('id');

    const ticket = await db.query.tickets.findFirst({
      where: eq(tickets.id, id),
    });

    if (!ticket) {
      throw new HTTPException(404, { message: 'Ticket not found' });
    }

    const cfValues = await db.query.customFieldValues.findMany({
      where: eq(customFieldValues.ticket_id, id),
      with: {
        customField: true,
      },
    });

    return c.json({ ...ticket, custom_fields: cfValues });
  });

  // PATCH /:id — update ticket
  router.patch('/:id', async (c) => {
    const id = c.req.param('id');
    const body = await c.req.json();
    const parsed = UpdateTicketSchema.parse(body);

    const ticket = await db.query.tickets.findFirst({
      where: eq(tickets.id, id),
    });

    if (!ticket) {
      throw new HTTPException(404, { message: 'Ticket not found' });
    }

    // Validate lifecycle transition if status is changing
    if (parsed.status) {
      const queue = await db.query.queues.findFirst({
        where: eq(queues.id, ticket.queue_id),
      });

      if (queue?.lifecycle_id) {
        const lifecycle = await db.query.lifecycles.findFirst({
          where: eq(lifecycles.id, queue.lifecycle_id!),
        });

        if (lifecycle) {
          const def = lifecycle.definition as LifecycleDefinition;
          const result = lifecycleValidator.validateTransition(def, ticket.status, parsed.status);
          if (!result.valid) {
            throw new HTTPException(422, { message: result.error ?? 'Invalid transition' });
          }
        }
      }
    }

    const txList = [];

    if (parsed.subject && parsed.subject !== ticket.subject) {
      txList.push({
        ticket_id: id,
        transaction_type: 'StatusChange' as const,
        field: 'subject',
        old_value: ticket.subject,
        new_value: parsed.subject,
        creator_id: '00000000-0000-0000-0000-000000000000',
      });
    }

    if (parsed.status && parsed.status !== ticket.status) {
      txList.push({
        ticket_id: id,
        transaction_type: 'StatusChange' as const,
        field: 'status',
        old_value: ticket.status,
        new_value: parsed.status,
        creator_id: '00000000-0000-0000-0000-000000000000',
      });
    }

    if (parsed.owner_id && parsed.owner_id !== ticket.owner_id) {
      txList.push({
        ticket_id: id,
        transaction_type: 'SetOwner' as const,
        field: 'owner_id',
        old_value: ticket.owner_id ?? null,
        new_value: parsed.owner_id,
        creator_id: '00000000-0000-0000-0000-000000000000',
      });
    }

    // Update the ticket
    const updateData: Record<string, unknown> = {};
    if (parsed.subject) updateData.subject = parsed.subject;
    if (parsed.status) updateData.status = parsed.status;
    if (parsed.owner_id) updateData.owner_id = parsed.owner_id;
    updateData.updated_at = new Date();

    const [updated] = await db.update(tickets)
      .set(updateData as any)
      .where(eq(tickets.id, id))
      .returning();

    // Insert transactions
    if (txList.length > 0) {
      await db.insert(transactions).values(txList as any);
    }

    // Run scrips
    const prepared = await scripEngine.prepare(id, txList as any);
    const results = scripEngine.commit(prepared);

    return c.json({ ticket: updated, scrip_results: results });
  });

  // POST /:id/preview — dry-run scrips
  router.post('/:id/preview', async (c) => {
    const id = c.req.param('id');
    const body = await c.req.json();
    const parsed = UpdateTicketSchema.parse(body);

    const ticket = await db.query.tickets.findFirst({
      where: eq(tickets.id, id),
    });

    if (!ticket) {
      throw new HTTPException(404, { message: 'Ticket not found' });
    }

    const txList: any[] = [];

    if (parsed.status && parsed.status !== ticket.status) {
      txList.push({
        id: '00000000-0000-0000-0000-000000000000',
        ticket_id: id,
        transaction_type: 'StatusChange',
        field: 'status',
        old_value: ticket.status,
        new_value: parsed.status,
        creator_id: '00000000-0000-0000-0000-000000000000',
      });
    }

    const prepared = await scripEngine.prepare(id, txList);
    const preparedWithDryRun = prepared.map((p) => ({ ...p, dryRun: true }));
    const results = scripEngine.commit(preparedWithDryRun);

    return c.json({ prepared_scrips: results });
  });

  // GET /:id/transactions — list transactions for ticket
  router.get('/:id/transactions', async (c) => {
    const id = c.req.param('id');

    const result = await db.query.transactions.findMany({
      where: eq(transactions.ticket_id, id),
      orderBy: asc(transactions.created_at),
    });

    return c.json(result);
  });

  return router;
}