package functionset

import (
	"encoding/json"

	function "example.com/database/function"

	"gorm.io/gorm"
)

type FunctionSet struct {
	gorm.Model
	Functions []function.Function `gorm:"many2many:functionset_function_associations" json:"functions"`
}

type FunctionSetParams struct {
	// ID(s) of the object being modified
	IDArray []uint
	// New fields
	Functions []uint `json:"functions"`
}

func (params *FunctionSetParams) parse(IDUintArray *[]uint, body *[]byte) error {
	var inputParams FunctionSetParams
	params.IDArray = *IDUintArray
	if len(*body) == 0 {
		return nil
	}
	err := json.Unmarshal(*body, &inputParams)
	if err != nil {
		return err
	}
	params.Functions = inputParams.Functions
	return nil
}

func (functionSet FunctionSet) create(db *gorm.DB) error {
	result := db.Create(&functionSet)
	if result.Error != nil {
		return result.Error
	}
	return nil
}

func (functionSet *FunctionSet) getAssociations(db *gorm.DB) {
	db.Model(&functionSet).Association("Functions").Find(&functionSet.Functions)
}

func (functionSet *FunctionSet) get(db *gorm.DB, inputFunctionSet uint) error {
	result := db.Model(&FunctionSet{}).Where("id = ?", inputFunctionSet).Take(&functionSet)
	if result.Error != nil {
		return result.Error
	}
	functionSet.getAssociations(db)
	return nil
}

func (functionSet FunctionSet) update(db *gorm.DB) error {
	// Get the original FunctionSet object
	var originalFunctionSet FunctionSet
	result := db.Model(&FunctionSet{}).Where("id = ?", functionSet.Model.ID).Take(&originalFunctionSet)
	if result.Error != nil {
		return result.Error
	}
	// Set the associated values by grabbing them from the database
	functionsError := db.Model(&originalFunctionSet).Association("Functions").Replace(&functionSet.Functions)
	if functionsError != nil {
		return functionsError
	}
	db.Save(&originalFunctionSet)
	return nil
}

func (functionSet FunctionSet) delete(db *gorm.DB) error {
	result := db.Unscoped().Delete(&functionSet)
	if result.Error != nil {
		return result.Error
	}
	return nil
}

func Create(db *gorm.DB, params FunctionSetParams) error {
	var newFunctions []function.Function
	var err error
	if len(params.Functions) > 0 {
		newFunctions, err = function.Get(db, params.Functions)
		if err != nil {
			return err
		}
	}
	return FunctionSet{
		Functions: newFunctions,
	}.create(db)
}

func Get(db *gorm.DB, inputFunctionSets []uint) ([]FunctionSet, error) {
	var outputFunctionSets []FunctionSet
	if len(inputFunctionSets) < 1 {
		db.Model(&FunctionSet{}).Select("id").Find(&inputFunctionSets)
	}
	for _, inputFunctionSet := range inputFunctionSets {
		var outputFunctionSet FunctionSet
		err := outputFunctionSet.get(db, inputFunctionSet)
		if err != nil {
			return nil, err
		}
		outputFunctionSets = append(outputFunctionSets, outputFunctionSet)
	}
	return outputFunctionSets, nil
}

func Update(db *gorm.DB, params FunctionSetParams) error {
	var newFunctions []function.Function
	var err error
	if len(params.Functions) > 0 {
		newFunctions, err = function.Get(db, params.Functions)
		if err != nil {
			return err
		}
	}
	return FunctionSet{
		Model:     gorm.Model{ID: params.IDArray[0]},
		Functions: newFunctions,
	}.update(db)
}

func Delete(db *gorm.DB, inputFunctionSets []uint) error {
	var functionSets []FunctionSet
	// if len(inputFunctionSets) < 1 {
	// 	result := db.Model(&FunctionSet{}).Select("id").Find(&inputFunctionSets)
	// 	if result.Error != nil {
	// 		return result.Error
	// 	}
	// }
	for _, inputFunctionSet := range inputFunctionSets {
		var functionSet FunctionSet
		functionSet.get(db, inputFunctionSet)
		functionSets = append(functionSets, functionSet)
	}
	for _, functionSet := range functionSets {
		err := functionSet.delete(db)
		if err != nil {
			return err
		}
	}
	return nil
}

func HandleRequest(method string, db *gorm.DB, IDUintArray *[]uint, body *[]byte) ([]FunctionSet, error) {
	var err error
	var params FunctionSetParams
	err = params.parse(IDUintArray, body)
	if err != nil {
		return nil, err
	}
	var result []FunctionSet
	switch method {
	case "GET":
		result, err = Get(db, params.IDArray)
	case "POST":
		err = Create(db, params)
	case "PUT":
		err = Update(db, params)
	case "DELETE":
		err = Delete(db, params.IDArray)
	}
	return result, err
}