import Fluent
import Leaf
import Vapor

struct EmployeeViewController: RouteCollection {

  private let api = ApiController()

  func boot(routes: any RoutesBuilder) throws {
    let employees = routes.protected.grouped("employees")
    employees.get(use: index(req:))
    employees.get("form", use: employeeForm(req:))
    employees.post(use: postEmployeeForm(req:))
    employees.group(":employeeID") {
      $0.get(use: editEmployee(req:))
      $0.delete(use: deleteEmployee(req:))
      $0.put(use: updateEmployee(req:))
      $0.post("toggle-active", use: toggleActiveEmployee(req:))
    }
  }

  @Sendable
  func index(req: Request) async throws -> View {
    return try await req.view.render("employees", EmployeesCTX(api: api, req: req))
  }

  @Sendable
  func postEmployeeForm(req: Request) async throws -> View {
    _ = try await api.createEmployee(req: req)
    let employees = try await api.getSortedEmployees(req: req)
    return try await req.view.render("employee-table", ["employees": employees])
  }

  @Sendable
  func toggleActiveEmployee(req: Request) async throws -> View {
    guard let employee = try await Employee.find(req.parameters.get("employeeID"), on: req.db) else {
      throw Abort(.notFound)
    }
    employee.active.toggle()
    try await employee.save(on: req.db)
    let employees = try await api.getSortedEmployees(req: req)
    return try await req.view.render("employee-table", ["employees": employees])
  }

  @Sendable
  func deleteEmployee(req: Request) async throws -> View {
    _ = try await api.deleteEmployee(req: req)
    let employees = try await api.getSortedEmployees(req: req)
    return try await req.view.render("employee-table", ["employees": employees])
  }

  @Sendable
  func editEmployee(req: Request) async throws -> View {
    guard let employee = try await Employee.find(req.parameters.get("employeeID"), on: req.db) else {
      throw Abort(.notFound)
    }
    return try await req.view.render("employee-form", EmployeeFormCTX(employee: employee.toDTO()))
  }

  @Sendable
  func updateEmployee(req: Request) async throws -> View {
    _ = try await api.updateEmployee(req: req)
    return try await req.view.render("employees", EmployeesCTX(oob: true, api: api, req: req))
  }

  @Sendable
  func employeeForm(req: Request) async throws -> View {
    try await req.view.render("employee-form", EmployeeFormCTX())
  }

}

private struct EmployeesCTX: Content {
  let oob: Bool
  let employees: [Employee.DTO]
  let form: EmployeeFormCTX

  init(
    oob: Bool = false,
    employee: Employee? = nil,
    api: ApiController,
    req: Request
  ) async throws {
    self.oob = oob
    self.employees = try await api.getSortedEmployees(req: req)
    self.form = .init(employee: employee.map { $0.toDTO() })
  }
}

private struct EmployeeFormCTX: Content {
  let employee: Employee.DTO?
  let oob: Bool

  init(employee: Employee.DTO? = nil) {
    self.employee = employee
    self.oob = employee != nil
  }
}

private extension ApiController {

  func getSortedEmployees(req: Request) async throws -> [Employee.DTO] {
    var employees = try await employeesIndex(req: req)
    employees.sort { ($0.active ?? false) && !($1.active ?? false) }
    employees.sort { ($0.lastName ?? "") < ($1.lastName ?? "") }
    return employees
  }
}