package logs

import (
	"context"
	"encoding/json"
	"errors"

	"git.aiterp.net/rpdata/logbot3/internal/api"
	"git.aiterp.net/rpdata/logbot3/internal/models"
)

// ErrNoneOpen is returned by FindOpen if no logs are open, but the query did succeed.
var ErrNoneOpen = errors.New("No open logs")

// FindOpen lists all changes according to the filter.
func FindOpen(ctx context.Context, channelName string) (models.Log, error) {
	data, err := api.Global().Query(ctx, findOpenGQL, map[string]interface{}{"channel": channelName}, nil)
	if err != nil {
		return models.Log{}, err
	}

	res := findOpenResult{}
	err = json.Unmarshal(data, &res)
	if err != nil {
		return models.Log{}, err
	}
	if len(res.Logs) == 0 {
		return models.Log{}, ErrNoneOpen
	}

	// This shouldn't happen, but if there are more than one
	// open logs for a channel, select the most recent one.
	selected := res.Logs[0]
	for _, log := range res.Logs[1:] {
		if log.Date.After(selected.Date) {
			selected = log
		}
	}

	return selected, nil
}

type findOpenResult struct {
	Logs []models.Log `json:"logs"`
}

var findOpenGQL = `
	query FindOpen($channel:String!) {
		logs(filter:{open:true, channels:[$channel]}) {
			id
			date
			channelName
			title
			eventName
			description
			open
			posts {
				id
				time
				kind
				nick
				text
			}
		}
	}
`