package main

import (
	"encoding/json"
	"strconv"

	"github.com/julienschmidt/httprouter"
)

func init() {
	router.GET("/api/questions/:qid/proposals", apiAuthHandler(questionAuthHandler(
		func(q Question, u *User, _ []byte) HTTPResponse {
			return formatApiResponse(q.GetProposals())
		}), loggedUser))
	router.GET("/api/surveys/:sid/questions/:qid/proposals", apiAuthHandler(questionAuthHandler(
		func(q Question, u *User, _ []byte) HTTPResponse {
			return formatApiResponse(q.GetProposals())
		}), loggedUser))
	router.POST("/api/surveys/:sid/questions/:qid/proposals", apiAuthHandler(questionAuthHandler(func(q Question, u *User, body []byte) HTTPResponse {
		var new Proposal
		if err := json.Unmarshal(body, &new); err != nil {
			return APIErrorResponse{err: err}
		}

		return formatApiResponse(q.NewProposal(new.Label))
	}), adminRestricted))
	router.PUT("/api/surveys/:sid/questions/:qid/proposals/:pid", apiAuthHandler(proposalAuthHandler(func(current Proposal, u *User, body []byte) HTTPResponse {
		var new Proposal
		if err := json.Unmarshal(body, &new); err != nil {
			return APIErrorResponse{err: err}
		}

		new.Id = current.Id
		return formatApiResponse(new.Update())
	}), adminRestricted))
	router.DELETE("/api/surveys/:sid/questions/:qid/proposals/:pid", apiAuthHandler(proposalAuthHandler(func(p Proposal, u *User, body []byte) HTTPResponse {
		return formatApiResponse(p.Delete())
	}), adminRestricted))
}

func proposalHandler(f func(Proposal, []byte) HTTPResponse) func(httprouter.Params, []byte) HTTPResponse {
	return func(ps httprouter.Params, body []byte) HTTPResponse {
		var question *Question = nil

		if qid, err := strconv.Atoi(string(ps.ByName("qid"))); err == nil {
			if q, err := getQuestion(qid); err == nil {
				question = &q
			}
		}

		if pid, err := strconv.Atoi(string(ps.ByName("pid"))); err != nil {
			return APIErrorResponse{err: err}
		} else if question == nil {
			if proposal, err := getProposal(pid); err != nil {
				return APIErrorResponse{err: err}
			} else {
				return f(proposal, body)
			}
		} else {
			if proposal, err := question.GetProposal(pid); err != nil {
				return APIErrorResponse{err: err}
			} else {
				return f(proposal, body)
			}
		}
	}
}

func proposalAuthHandler(f func(Proposal, *User, []byte) HTTPResponse) func(*User, httprouter.Params, []byte) HTTPResponse {
	return func(u *User, ps httprouter.Params, body []byte) HTTPResponse {
		return proposalHandler(func(p Proposal, body []byte) HTTPResponse {
			return f(p, u, body)
		})(ps, body)
	}
}

type Proposal struct {
	Id         int64  `json:"id"`
	IdQuestion int64  `json:"id_question"`
	Label      string `json:"label"`
}

func (q *Question) GetProposals() (proposals []Proposal, err error) {
	if rows, errr := DBQuery("SELECT id_proposal, id_question, label FROM survey_proposals WHERE id_question=?", q.Id); errr != nil {
		return nil, errr
	} else {
		defer rows.Close()

		for rows.Next() {
			var p Proposal
			if err = rows.Scan(&p.Id, &p.IdQuestion, &p.Label); err != nil {
				return
			}
			proposals = append(proposals, p)
		}
		if err = rows.Err(); err != nil {
			return
		}

		return
	}
}

func getProposal(id int) (p Proposal, err error) {
	err = DBQueryRow("SELECT id_proposal, id_question, label FROM survey_proposals WHERE id_proposal=?", id).Scan(&p.Id, &p.IdQuestion, &p.Label)
	return
}

func (q *Question) GetProposal(id int) (p Proposal, err error) {
	err = DBQueryRow("SELECT id_proposal, id_question, label FROM survey_proposals WHERE id_proposal=? AND id_question=?", id, q.Id).Scan(&p.Id, &p.IdQuestion, &p.Label)
	return
}

func (q *Question) NewProposal(label string) (Proposal, error) {
	if res, err := DBExec("INSERT INTO survey_proposals (id_question, label) VALUES (?, ?)", q.Id, label); err != nil {
		return Proposal{}, err
	} else if pid, err := res.LastInsertId(); err != nil {
		return Proposal{}, err
	} else {
		return Proposal{pid, q.Id, label}, nil
	}
}

func (p Proposal) Update() (Proposal, error) {
	_, err := DBExec("UPDATE survey_proposals SET id_question = ?, label = ? WHERE id_proposal = ?", p.IdQuestion, p.Label, p.Id)
	return p, err
}

func (p Proposal) Delete() (int64, error) {
	if res, err := DBExec("DELETE FROM survey_proposals WHERE id_proposal = ?", p.Id); err != nil {
		return 0, err
	} else if nb, err := res.RowsAffected(); err != nil {
		return 0, err
	} else {
		return nb, err
	}
}

func ClearProposals() (int64, error) {
	if res, err := DBExec("DELETE FROM survey_proposals"); err != nil {
		return 0, err
	} else if nb, err := res.RowsAffected(); err != nil {
		return 0, err
	} else {
		return nb, err
	}
}