package main

import (
	"fmt"
	"log"
)

type (
	WeightService struct {
		db *DB
	}
	Weight struct {
		Rowid  int64   `json:"rowid"`
		Date   string  `json:"date"`
		Weight float32 `json:"weight"`
	}
	AggregatedWeight struct {
		Period string  `json:"period"`
		Amount float32 `json:"amount"`
	}
)

const weightcolumns = "rowid, date, weight"
const weightAggregatedColumns = "period, amount"

func (w *WeightService) GetRecent() ([]Weight, error) {
	var res []Weight
	if w.db == nil || !w.db.Ready {
		return res, fmt.Errorf("cannot get recent weight, db is nil or is not ready")
	}

	row, err := w.db.readConn.Query(fmt.Sprintf("SELECT %s from weightView WHERE date > datetime('now', '-%d days') order by date desc;", weightcolumns, Settings.WeightDaysLookback))
	if err != nil {
		log.Printf("error getting daily weight: %v", err)
		return res, err
	}

	for row.Next() {
		var weight Weight
		err := row.Scan(&weight.Rowid, &weight.Date, &weight.Weight)
		if err != nil {
			log.Printf("error scanning row: %v", err)
			continue
		}

		res = append(res, weight)
	}

	return res, nil
}

func (w *WeightService) Create(weight Weight) (Weight, error) {
	if w.db == nil || !w.db.Ready {
		return weight, fmt.Errorf("cannot create weight, db is nil or is not ready")
	}
	if weight.Weight <= 0 {
		return weight, fmt.Errorf("cannot create weight, weight is empty")
	}

	res, err := w.db.writeConn.Exec("INSERT INTO weight (weight) VALUES (?)", weight.Weight)
	if err != nil {
		return weight, fmt.Errorf("error inserting weight: %v", err)
	}

	rowid, err := res.LastInsertId()
	if err != nil {
		return weight, fmt.Errorf("error getting last insert id: %v", err)
	}

	return w.GetByRowid(rowid)
}

func (w *WeightService) GetByRowid(rowid int64) (Weight, error) {
	var res Weight
	if w.db == nil || !w.db.Ready {
		return res, fmt.Errorf("cannot get weight by rowid, db is nil or is not ready")
	}

	row := w.db.readConn.QueryRow(fmt.Sprintf("SELECT %s from weightView WHERE rowid = ?", weightcolumns), rowid)
	err := row.Scan(&res.Rowid, &res.Date, &res.Weight)
	if err != nil {
		return res, fmt.Errorf("error scanning row: %v", err)
	}

	return res, nil
}

// I could probably refactor this to be less of a disaster...
// But I think it'll work for now
func (w *WeightService) GetDaily() ([]AggregatedWeight, error) {
	var res []AggregatedWeight
	if w.db == nil || !w.db.Ready {
		return res, fmt.Errorf("cannot get daily weight, db is nil or is not ready")
	}

	row, err := w.db.readConn.Query(fmt.Sprintf("SELECT %s from weightDaily LIMIT %d", weightAggregatedColumns, Settings.WeightDailyLookback))
	if err != nil {
		log.Printf("error getting daily weight: %v", err)
		return res, err
	}

	for row.Next() {
		var weight AggregatedWeight
		err := row.Scan(&weight.Period, &weight.Amount)
		if err != nil {
			log.Printf("error scanning row: %v", err)
			continue
		}

		res = append(res, weight)
	}

	return res, nil
}

func (w *WeightService) GetWeekly() ([]AggregatedWeight, error) {
	var res []AggregatedWeight
	if w.db == nil || !w.db.Ready {
		return res, fmt.Errorf("cannot get weekly weight, db is nil or is not ready")
	}

	row, err := w.db.readConn.Query(fmt.Sprintf("SELECT %s from weightWeekly LIMIT %d", weightAggregatedColumns, Settings.WeightWeeklyLookback))
	if err != nil {
		log.Printf("error getting weekly weight: %v", err)
		return res, err
	}

	for row.Next() {
		var weight AggregatedWeight
		err := row.Scan(&weight.Period, &weight.Amount)
		if err != nil {
			log.Printf("error scanning row: %v", err)
			continue
		}

		res = append(res, weight)
	}

	return res, nil
}

func (w *WeightService) GetMonthly() ([]AggregatedWeight, error) {
	var res []AggregatedWeight
	if w.db == nil || !w.db.Ready {
		return res, fmt.Errorf("cannot get monthly weight, db is nil or is not ready")
	}

	row, err := w.db.readConn.Query(fmt.Sprintf("SELECT %s from weightMonthly LIMIT %d", weightAggregatedColumns, Settings.WeightMonthlyLookback))
	if err != nil {
		log.Printf("error getting monthly weight: %v", err)
		return res, err
	}

	for row.Next() {
		var weight AggregatedWeight
		err := row.Scan(&weight.Period, &weight.Amount)
		if err != nil {
			log.Printf("error scanning row: %v", err)
			continue
		}

		res = append(res, weight)
	}

	return res, nil
}

func (w *WeightService) GetYearly() ([]AggregatedWeight, error) {
	var res []AggregatedWeight
	if w.db == nil || !w.db.Ready {
		return res, fmt.Errorf("cannot get yearly weight, db is nil or is not ready")
	}

	row, err := w.db.readConn.Query(fmt.Sprintf("SELECT %s from weightYearly LIMIT %d", weightAggregatedColumns, Settings.WeightYearlyLookback))
	if err != nil {
		log.Printf("error getting yearly weight: %v", err)
		return res, err
	}

	for row.Next() {
		var weight AggregatedWeight
		err := row.Scan(&weight.Period, &weight.Amount)
		if err != nil {
			log.Printf("error scanning row: %v", err)
			continue
		}

		res = append(res, weight)
	}

	return res, nil
}