/*
Copyright 2017-2022 CAcert Inc.
SPDX-License-Identifier: Apache-2.0

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package models

import (
	"fmt"
	"log"
	"time"

	"github.com/jmoiron/sqlx"
)

type VoteType uint8

const unknownVariant = "unknown"

const (
	VoteTypeMotion VoteType = 0
	VoteTypeVeto   VoteType = 1
)

var voteTypeLabels = map[VoteType]string{
	VoteTypeMotion: "motion",
	VoteTypeVeto:   "veto",
}

func (v VoteType) String() string {
	if label, ok := voteTypeLabels[v]; ok {
		return label
	}

	return unknownVariant
}

func (v VoteType) QuorumAndMajority() (int, float32) {
	const (
		majorityDefault = 0.99
		majorityMotion  = 0.50
		quorumDefault   = 1
		quorumMotion    = 3
	)

	if v == VoteTypeMotion {
		return quorumMotion, majorityMotion
	}

	return quorumDefault, majorityDefault
}

type VoteStatus int8

const (
	voteStatusDeclined  VoteStatus = -1
	voteStatusPending   VoteStatus = 0
	voteStatusApproved  VoteStatus = 1
	voteStatusWithdrawn VoteStatus = -2
)

var voteStatusLabels = map[VoteStatus]string{
	voteStatusDeclined:  "declined",
	voteStatusPending:   "pending",
	voteStatusApproved:  "approved",
	voteStatusWithdrawn: "withdrawn",
}

func (v VoteStatus) String() string {
	if label, ok := voteStatusLabels[v]; ok {
		return label
	}

	return unknownVariant
}

type VoteChoice int

const (
	voteAye     VoteChoice = 1
	voteNaye    VoteChoice = -1
	voteAbstain VoteChoice = 0
)

var voteChoiceLabels = map[VoteChoice]string{
	voteAye:     "aye",
	voteNaye:    "naye",
	voteAbstain: "abstain",
}

func (v VoteChoice) String() string {
	if label, ok := voteChoiceLabels[v]; ok {
		return label
	}

	return unknownVariant
}

type Decision struct {
	ID        int64 `db:"id"`
	Proposed  time.Time
	Proponent int64 `db:"proponent"`
	Title     string
	Content   string
	Quorum    int
	Majority  int
	Status    VoteStatus
	Due       time.Time
	Modified  time.Time
	Tag       string
	VoteType  VoteType
}

type DecisionModel struct {
	DB      *sqlx.DB
	InfoLog *log.Logger
}

// Create a new decision.
func (m *DecisionModel) Create(
	proponent *Voter,
	voteType VoteType,
	title, content string,
	proposed, due time.Time,
) (int64, error) {
	d := &Decision{
		Proposed:  proposed.UTC(),
		Proponent: proponent.ID,
		Title:     title,
		Content:   content,
		Due:       due.UTC(),
		VoteType:  voteType,
	}

	result, err := m.DB.NamedExec(`INSERT INTO decisions
(proposed, proponent, title, content, votetype, status, due, modified, tag)
VALUES (:proposed, :proponent, :title, :content, :votetype, :status, :due, :proposed,
        'm' || strftime('%Y%m%d', :proposed) || '.' || (
    SELECT COUNT(*)+1 AS num
    FROM decisions
    WHERE proposed BETWEEN date(:proposed) AND date(:proposed, '1 day')
))`, d)
	if err != nil {
		return 0, fmt.Errorf("creating motion failed: %w", err)
	}

	id, err := result.LastInsertId()
	if err != nil {
		return 0, fmt.Errorf("could not get inserted decision id: %w", err)
	}

	return id, nil
}

func (m *DecisionModel) CloseDecisions() error {
	rows, err := m.DB.NamedQuery(`
SELECT decisions.id, decisions.tag, decisions.proponent, decisions.proposed, decisions.title, decisions.content,
       decisions.votetype, decisions.status, decisions.due, decisions.modified
FROM   decisions
WHERE  decisions.status=0 AND :now > due`, struct{ Now time.Time }{Now: time.Now().UTC()})
	if err != nil {
		return fmt.Errorf("fetching closable decisions failed: %w", err)
	}

	defer func(rows *sqlx.Rows) {
		_ = rows.Close()
	}(rows)

	decisions := make([]*Decision, 0)

	for rows.Next() {
		decision := &Decision{}
		if err = rows.StructScan(decision); err != nil {
			return fmt.Errorf("scanning row failed: %w", err)
		}

		if rows.Err() != nil {
			return fmt.Errorf("row error: %w", err)
		}

		decisions = append(decisions, decision)
	}

	for _, decision := range decisions {
		m.InfoLog.Printf("found closable decision %s", decision.Tag)

		if err = m.Close(decision.Tag); err != nil {
			return fmt.Errorf("closing decision %s failed: %w", decision.Tag, err)
		}
	}

	return nil
}

func (m *DecisionModel) Close(tag string) error {
	panic("not implemented")
}

func (m *DecisionModel) FindUnVotedDecisionsForVoter(v *Voter) ([]Decision, error) {
	panic("not implemented")
}