package com.rit.whatsapp.service;

import com.google.cloud.firestore.Firestore;
import com.google.cloud.firestore.QueryDocumentSnapshot;
import com.google.cloud.firestore.QuerySnapshot;
import com.google.cloud.storage.Blob;
import com.google.cloud.storage.Bucket;
import com.rit.whatsapp.model.GrievanceDraft;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.UUID;
import java.util.concurrent.TimeUnit;
import com.google.cloud.Timestamp;

@Service
public class FirebaseService {

    private final Firestore firestore;
    private final Bucket bucket;

    @Autowired
    public FirebaseService(@Autowired(required = false) Firestore firestore,
                           @Autowired(required = false) Bucket bucket) {
        this.firestore = firestore;
        this.bucket = bucket;
    }

    public List<String> getDepartments(String org) {
        List<String> deps = new ArrayList<>();
        if (firestore == null) return deps;
        try {
            QuerySnapshot snapshot = firestore.collection("departments")
                    .whereEqualTo("org", org)
                    .get().get();
            for (QueryDocumentSnapshot doc : snapshot.getDocuments()) {
                Boolean isDeleted = doc.getBoolean("isDeleted");
                if (isDeleted == null || !isDeleted) {
                    deps.add(doc.getString("name"));
                }
            }
        } catch (Exception e) {
            System.err.println("Error fetching departments: " + e.getMessage());
        }
        return deps;
    }

    public List<Map<String, Object>> getUserGrievances(String imsId) {
        List<Map<String, Object>> list = new ArrayList<>();
        if (firestore == null) return list;
        try {
            QuerySnapshot snapshot = firestore.collection("grievances")
                    .whereEqualTo("studentRegNo", imsId)
                    .get().get();
            for (QueryDocumentSnapshot doc : snapshot.getDocuments()) {
                Map<String, Object> data = new HashMap<>(doc.getData());
                data.put("id", doc.getId());
                list.add(data);
            }
        } catch (Exception e) {
            System.err.println("Error fetching grievances: " + e.getMessage());
        }
        return list;
    }

    public String uploadImage(byte[] imageBytes, String mimeType, String ticketId) {
        if (bucket == null || imageBytes == null) return null;
        try {
            String extension = mimeType != null && mimeType.contains("png") ? ".png" : ".jpg";
            String blobName = "grievances/" + ticketId + "/" + UUID.randomUUID() + extension;
            Blob blob = bucket.create(blobName, imageBytes, mimeType != null ? mimeType : "image/jpeg");
            return blob.signUrl(7, TimeUnit.DAYS).toString();
        } catch (Exception e) {
            System.err.println("Failed to upload image to Firebase Storage: " + e.getMessage());
            return null;
        }
    }

    public void saveGrievance(GrievanceDraft draft) {
        if (firestore == null) {
            System.out.println("Firestore not configured.");
            return;
        }
        try {
            Map<String, Object> data = new HashMap<>();
            data.put("userId", "whatsapp_" + draft.getPhoneNumber());
            data.put("title", draft.getTitle());
            data.put("description", draft.getDescription());
            data.put("department", draft.getDepartment());
            data.put("org", "RIT");
            data.put("studentName", draft.getStudentName());
            data.put("studentRegNo", draft.getImsId());
            data.put("status", draft.getStatus());
            data.put("createdAt", Timestamp.now());
            if (draft.getImageUrl() != null) {
                data.put("imageUrl", draft.getImageUrl());
            }
            firestore.collection("grievances").document(draft.getTicketId()).set(data).get();
        } catch (Exception e) {
            System.err.println("Failed to save grievance: " + e.getMessage());
        }
    }

    public void deleteGrievance(String ticketId) {
        if (firestore != null) {
            try {
                firestore.collection("grievances").document(ticketId).delete().get();
                System.out.println("Deleted Firestore document: " + ticketId);
            } catch (Exception e) {
                System.err.println("Failed to delete Firestore document: " + e.getMessage());
            }
        }
        if (bucket != null) {
            try {
                Iterable<Blob> blobs = bucket.list(com.google.cloud.storage.Storage.BlobListOption.prefix("grievances/" + ticketId + "/")).iterateAll();
                for (Blob blob : blobs) {
                    blob.delete();
                    System.out.println("Deleted Storage blob: " + blob.getName());
                }
            } catch (Exception e) {
                System.err.println("Failed to delete Storage blobs: " + e.getMessage());
            }
        }
    }
}