import { Router } from "express";
import { AuthRequest, requireAuth } from "../middleware/auth.js";
import { canAccessTask, User } from "../lib/auth-utils.js";
import { db } from "@workspace/db";
import { commentsTable, usersTable, notificationsTable, tasksTable } from "@workspace/db";
import { eq } from "drizzle-orm";
import { ListTaskCommentsParams } from "@workspace/api-zod";
import { logAudit } from "../lib/audit-logger.js";
import { z } from "zod";

const router = Router();

router.get("/tasks/:id/comments", requireAuth, async (req: AuthRequest, res) => {
  try {
    const user = req.user as User;
    if (!user) { res.status(401).json({ error: "Unauthorized" }); return; }

    const { id } = ListTaskCommentsParams.parse({ id: Number(req.params.id) });

    const [task] = await db.select().from(tasksTable).where(eq(tasksTable.id, id));
    if (!task) { res.status(404).json({ error: "Task not found" }); return; }

    if (!canAccessTask(user, task)) {
      res.status(403).json({ error: "Forbidden: You do not have access to this task's comments" });
      return;
    }

    const comments = await db.select().from(commentsTable)
      .where(eq(commentsTable.taskId, id))
      .orderBy(commentsTable.createdAt);

    const userIds = [...new Set(comments.map(c => c.userId).filter(Boolean))] as number[];
    const users = userIds.length > 0
      ? await db.select().from(usersTable)
          .then(all => all.filter(u => userIds.includes(u.id)))
      : [];
    const userMap = Object.fromEntries(users.map(u => [u.id, { ...u, createdAt: u.createdAt.toISOString() }]));

    res.json(comments.map(c => ({
      ...c,
      createdAt: c.createdAt.toISOString(),
      user: c.userId ? userMap[c.userId] ?? null : null,
    })));
  } catch (err) {
    req.log.error({ err }, "Failed to list comments");
    res.status(500).json({ error: "Internal server error" });
  }
});

const createCommentSchema = z.object({
  taskId: z.coerce.number().int().positive("معرف المهمة غير صالح"),
  content: z.string().trim().min(1, "محتوى التعليق مطلوب"),
  mentionedUserIds: z.array(z.coerce.number().int().positive("معرف المستخدم غير صالح")).optional(),
}).strict();

async function handleCreateComment(req: AuthRequest, res: any) {
  try {
    const requestingUser = req.user as User;
    if (!requestingUser) { res.status(401).json({ error: "Unauthorized" }); return; }

    const bodyData = req.params.id !== undefined ? { taskId: req.params.id, ...req.body } : req.body;
    const parseResult = createCommentSchema.safeParse(bodyData);
    if (!parseResult.success) {
      res.status(400).json({ error: parseResult.error.errors[0].message });
      return;
    }

    const { taskId, content, mentionedUserIds } = parseResult.data;

    const [task] = await db.select().from(tasksTable).where(eq(tasksTable.id, taskId));
    if (!task) { res.status(404).json({ error: "Task not found" }); return; }

    if (!canAccessTask(requestingUser, task)) {
      res.status(403).json({ error: "Forbidden: You do not have permission to comment on this task" });
      return;
    }

    const [comment] = await db.insert(commentsTable).values({
      taskId,
      userId: requestingUser.id,
      content,
    }).returning();

    logAudit({
      userId: requestingUser.id,
      action: "comment_created",
      entityType: "comment",
      entityId: comment.id,
      details: {
        commentId: comment.id,
        taskId: comment.taskId,
        content: comment.content,
        mentionedUserIds: mentionedUserIds ?? [],
      },
      req,
    });

    if (task) {
      const notifyUserIds = new Set<number>();
      if (task.createdByUserId && task.createdByUserId !== requestingUser.id) notifyUserIds.add(task.createdByUserId);
      if (task.assignedUserId && task.assignedUserId !== requestingUser.id) notifyUserIds.add(task.assignedUserId);
      if (mentionedUserIds && mentionedUserIds.length > 0) {
        mentionedUserIds.forEach(uid => { if (uid !== requestingUser.id) notifyUserIds.add(uid); });
      }
      if (notifyUserIds.size > 0) {
        await db.insert(notificationsTable).values(
          [...notifyUserIds].map(uid => ({
            userId: uid,
            taskId,
            type: "comment_added",
            message: `تعليق جديد على المهمة: "${task.title}"`,
          }))
        );
      }
    }

    let commentAuthor = null;
    if (comment.userId) {
      const [u] = await db.select().from(usersTable).where(eq(usersTable.id, comment.userId));
      if (u) commentAuthor = { ...u, createdAt: u.createdAt.toISOString() };
    }

    res.status(201).json({
      ...comment,
      createdAt: comment.createdAt.toISOString(),
      user: commentAuthor,
    });
  } catch (err) {
    req.log.error({ err: err instanceof Error ? err.message : String(err) }, "Failed to create comment");
    res.status(500).json({ error: "Internal server error" });
  }
}

router.post("/tasks/:id/comments", requireAuth, handleCreateComment);
router.post("/comments", requireAuth, handleCreateComment);

export default router;