using AutoMapper;
using Microsoft.EntityFrameworkCore;
using OrdersManagementDataModel.Dtos;
using OrdersManagementDataModel.Entities;

namespace OrdersManagementDataModel.Services;

public class FunctionService(OrdersManagementDbContext context, IMapper mapper) : IFunctionService
{
    public async Task<IEnumerable<FunctionDto>> GetFunctions()
    {
        IList<FunctionDto> functions = await context.Functions.Select(x => mapper.Map<FunctionDto>(x)).ToListAsync();

        return functions;
    }
    
    public async Task<FunctionDto?> GetFunctionById(Guid id)
    {
        FunctionDto? function = await context.Functions.Where(x => x.RowPointer == id)
            .Select(x => mapper.Map<FunctionDto>(x)).FirstOrDefaultAsync();
        
        return function;
    }
    
    public async Task<FunctionDto?> GetFunctionByName(string name)
    {
        FunctionDto? function = await context.Functions.Where(x => x.Name == name)
            .Select(x => mapper.Map<FunctionDto>(x)).FirstOrDefaultAsync();
        
        return function;
    }
    
    public async Task<int> AddFunction(FunctionDto functionDto)
    {
        Function function = new Function
        {
            Name = functionDto.Name,
            RowPointer = Guid.NewGuid()
        };
        
        context.Functions.Add(function);
        return await context.SaveChangesAsync();
    }
    
    public async Task<int> DeleteFunction(Guid id)
    {
        Function? function = await context.Functions.Where(x => x.RowPointer == id).FirstOrDefaultAsync() ?? null;

        if (function == null) return 0;

        context.Functions.Remove(function);
        return await context.SaveChangesAsync();
    }
    
    public async Task<int> UpdateFunction(FunctionDto functionDto)
    {
        Function function = mapper.Map<Function>(functionDto);
        context.Functions.Update(function);
        return await context.SaveChangesAsync();
    }
    
    public async Task<IEnumerable<FunctionDto>> GetFunctionsByRoleId(Guid roleId)
    {
        Role? role = await context.Roles.FirstOrDefaultAsync(x => x.RowPointer == roleId);

        IList<FunctionDto> functions = await context.Functions.Where(x => role != null && x.RoleId == role.Id)
            .Select(x => mapper.Map<FunctionDto>(x)).ToListAsync();

        return functions;
    }
    
    public async Task<int> AddFunctionToRole(Guid roleId, Guid functionId)
    {
        Role? role = await context.Roles.FirstOrDefaultAsync(x => x.RowPointer == roleId);
        Function? function = await context.Functions.FirstOrDefaultAsync(x => x.RowPointer == functionId);

        if (role == null || function == null) return 0;

        function.RoleId = role.Id;
        context.Functions.Update(function);
        return await context.SaveChangesAsync();
    }
    
    public async Task<int> RemoveFunctionFromRole(Guid roleId, Guid functionId)
    {
        Role? role = await context.Roles.FirstOrDefaultAsync(x => x.RowPointer == roleId);
        Function? function = await context.Functions.FirstOrDefaultAsync(x => x.RowPointer == functionId);

        if (role == null || function == null) return 0;

        function.RoleId = 0;
        context.Functions.Update(function);
        return await context.SaveChangesAsync();
    }
}