package main

import (
	"encoding/json"
	"errors"
	"strconv"

	"srs.epita.fr/fic-server/libfic"
)

var ApiExercicesRouting = map[string]DispatchFunction{
	"GET":    listExercice,
	"PATCH":  updateExercice,
	"DELETE": deletionExercice,
}

func listExercice(args []string, body []byte) (interface{}, error) {
	if len(args) == 1 {
		if eid, err := strconv.Atoi(string(args[0])); err != nil {
			return nil, err
		} else {
			return fic.GetExercice(int64(eid))
		}
	} else {
		// List all exercices
		return fic.GetExercices()
	}
}

func deletionExercice(args []string, body []byte) (interface{}, error) {
	if len(args) == 1 {
		if eid, err := strconv.Atoi(string(args[0])); err != nil {
			return nil, err
		} else if exercice, err := fic.GetExercice(int64(eid)); err != nil {
			return nil, err
		} else {
			return exercice.Delete()
		}
	} else {
		return nil, nil
	}
}

type uploadedExercice struct {
	Title     string
	Statement string
	Hint      string
	Depend    *int64
	Gain      int
	VideoURI  string
}

func updateExercice(args []string, body []byte) (interface{}, error) {
	if len(args) == 1 {
		if eid, err := strconv.Atoi(string(args[0])); err != nil {
			return nil, err
		} else if exercice, err := fic.GetExercice(int64(eid)); err != nil {
			return nil, err
		} else {
			// Update an exercice
			var ue uploadedExercice
			if err := json.Unmarshal(body, &ue); err != nil {
				return nil, err
			}

			if len(ue.Title) == 0 {
				return nil, errors.New("Exercice's title not filled")
			}

			if ue.Depend != nil {
				if _, err := fic.GetExercice(*ue.Depend); err != nil {
					return nil, err
				}
			}

			exercice.Title = ue.Title
			exercice.Statement = ue.Statement
			exercice.Hint = ue.Hint
			exercice.Depend = ue.Depend
			exercice.Gain = int64(ue.Gain)
			exercice.VideoURI = ue.VideoURI

			return exercice.Update()
		}
	} else {
		return nil, nil
	}
}

func createExercice(theme fic.Theme, args []string, body []byte) (interface{}, error) {
	if len(args) >= 1 {
		if eid, err := strconv.Atoi(args[0]); err != nil {
			return nil, err
		} else if exercice, err := theme.GetExercice(eid); err != nil {
			return nil, err
		} else {
			if args[1] == "files" {
				return createExerciceFile(theme, exercice, args[2:], body)
			} else if args[1] == "keys" {
				return createExerciceKey(theme, exercice, args[2:], body)
			}
		}
		return nil, nil
	} else {
		// Create a new exercice
		var ue uploadedExercice
		if err := json.Unmarshal(body, &ue); err != nil {
			return nil, err
		}

		if len(ue.Title) == 0 {
			return nil, errors.New("Title not filled")
		}

		var depend *fic.Exercice = nil
		if ue.Depend != nil {
			if d, err := fic.GetExercice(*ue.Depend); err != nil {
				return nil, err
			} else {
				depend = &d
			}
		}

		return theme.AddExercice(ue.Title, ue.Statement, ue.Hint, depend, ue.Gain, ue.VideoURI)
	}
}

type uploadedKey struct {
	Name string
	Key  string
}

func createExerciceKey(theme fic.Theme, exercice fic.Exercice, args []string, body []byte) (interface{}, error) {
	var uk uploadedKey
	if err := json.Unmarshal(body, &uk); err != nil {
		return nil, err
	}

	if len(uk.Key) == 0 {
		return nil, errors.New("Key not filled")
	}

	return exercice.AddRawKey(uk.Name, uk.Key)
}