package com.hitcommunications.servermanager.services;

import com.hitcommunications.servermanager.mappers.ServersMapper;
import com.hitcommunications.servermanager.model.Servers;
import com.hitcommunications.servermanager.model.dtos.BulkServerImportResponse;
import com.hitcommunications.servermanager.model.dtos.BulkServerImportResponse.FailedRow;
import com.hitcommunications.servermanager.model.dtos.NewServerDTO;
import com.hitcommunications.servermanager.model.dtos.ServerDTO;
import com.hitcommunications.servermanager.model.enums.Applications;
import com.hitcommunications.servermanager.model.enums.DatabaseType;
import com.hitcommunications.servermanager.model.enums.ServersType;
import com.hitcommunications.servermanager.repositories.ServersRepository;
import lombok.RequiredArgsConstructor;
import org.springframework.stereotype.Service;
import org.springframework.web.multipart.MultipartFile;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.nio.charset.StandardCharsets;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.ArrayList;

@Service
@RequiredArgsConstructor
public class ServersService {
    private final ServersMapper mapper;
    private final ServersRepository repo;

    public ServerDTO create(NewServerDTO createDTO) {
        // Check if server with same IP and port already exists
        repo.findByIpAndPort(createDTO.ip(), createDTO.port()).ifPresent(entity -> {
            throw new RuntimeException("Server already exists with IP: " + createDTO.ip() + " and port: " + createDTO.port());
        });

        Servers entity = mapper.toEntity(createDTO);
        entity = repo.save(entity);
        return mapper.toDTO(entity);
    }

    public ServerDTO getById(String id) {
        return repo.findById(id)
                .map(mapper::toDTO)
                .orElseThrow(() -> new RuntimeException("Server not found with id: " + id));
    }

    public ServerDTO getByName(String name) {
        return repo.findByName(name)
                .map(mapper::toDTO)
                .orElseThrow(() -> new RuntimeException("Server not found with name: " + name));
    }

    public List<ServerDTO> getByType(ServersType type) {
        return repo.findByType(type)
                .stream()
                .map(mapper::toDTO)
                .toList();
    }

    public Map<ServersType, Integer> countAllByType() {
        Map<ServersType, Integer> response  = new HashMap<>();

        for(ServersType type : ServersType.values()) {
            response.put(type, repo.countAllByType(type));
        }

        return response;
    }

    public List<ServerDTO> getByApplication(Applications application) {
        return repo.findByApplication(application)
                .stream()
                .map(mapper::toDTO)
                .toList();
    }

    public BulkServerImportResponse bulkCreate(MultipartFile file) {
        List<FailedRow> failures = new ArrayList<>();
        int succeeded = 0;
        int processed = 0;

        try (BufferedReader reader = new BufferedReader(new InputStreamReader(file.getInputStream(), StandardCharsets.UTF_8))) {
            String line;
            int lineNumber = 0;
            while ((line = reader.readLine()) != null) {
                lineNumber++;
                if (line.isBlank()) {
                    continue;
                }

                String[] columns = parseColumns(line);
                if (isHeaderRow(columns)) {
                    continue;
                }

                processed++;
                try {
                    NewServerDTO dto = toNewServerDTO(columns);
                    create(dto);
                    succeeded++;
                } catch (Exception ex) {
                    failures.add(new FailedRow(lineNumber, ex.getMessage(), line));
                }
            }
        } catch (IOException e) {
            throw new RuntimeException("Erro ao ler arquivo CSV.", e);
        }

        int failed = failures.size();
        return new BulkServerImportResponse(processed, succeeded, failed, failures);
    }

    private String[] parseColumns(String line) {
        String[] rawColumns = line.split(";");
        String[] columns = new String[rawColumns.length];
        for (int i = 0; i < rawColumns.length; i++) {
            columns[i] = rawColumns[i].trim();
        }
        return columns;
    }

    private NewServerDTO toNewServerDTO(String[] columns) {
        if (columns.length < 8) {
            throw new IllegalArgumentException("Linha incompleta. Esperado 8 colunas.");
        }

        String name = columns[0];
        String ip = columns[1];
        Integer port = Integer.parseInt(columns[2]);
        String user = columns[3];
        String password = columns[4];
        ServersType type = ServersType.valueOf(columns[5].toUpperCase());
        Applications application = Applications.valueOf(columns[6].toUpperCase());
        DatabaseType dbType = DatabaseType.valueOf(columns[7].toUpperCase());

        return new NewServerDTO(name, ip, port, user, password, type, application, dbType);
    }

    private boolean isHeaderRow(String[] columns) {
        if (columns.length < 8) {
            return false;
        }
        return "name".equalsIgnoreCase(columns[0]) &&
                "ip".equalsIgnoreCase(columns[1]) &&
                "port".equalsIgnoreCase(columns[2]);
    }

    public List<ServerDTO> getAll() {
        return repo.findAll()
                .stream()
                .map(mapper::toDTO)
                .toList();
    }

    public ServerDTO update(String id, NewServerDTO updateDTO) {
        Servers entity = repo.findById(id)
                .orElseThrow(() -> new RuntimeException("Server not found with id: " + id));

        // Check if IP/port combination already exists (excluding current server)
        repo.findByIpAndPort(updateDTO.ip(), updateDTO.port()).ifPresent(existingServer -> {
            if (!existingServer.getId().equals(id)) {
                throw new RuntimeException("Server already exists with IP: " + updateDTO.ip() + " and port: " + updateDTO.port());
            }
        });

        mapper.partialUpdate(updateDTO, entity);
        entity = repo.save(entity);
        return mapper.toDTO(entity);
    }

    public void delete(String id) {
        if (!repo.existsById(id)) {
            throw new RuntimeException("Server not found with id: " + id);
        }
        repo.deleteById(id);
    }
}