package telebot

import (
	"github.com/mitchellh/hashstructure"
	"hash/fnv"
	"strconv"
)

// inlineQueryHashOptions sets the HashOptions to be used when hashing
// an inline query result (used to generate IDs).
var inlineQueryHashOptions = &hashstructure.HashOptions{
	Hasher: fnv.New64(),
}

// Query is an incoming inline query. When the user sends
// an empty query, your bot could return some default or
// trending results.
type Query struct {
	// Unique identifier for this query.
	ID string `json:"id"`

	// Sender.
	From User `json:"from"`

	// (Optional) Sender location, only for bots that request user location.
	Location Location `json:"location"`

	// Text of the query (up to 512 characters).
	Text string `json:"query"`

	// Offset of the results to be returned, can be controlled by the bot.
	Offset string `json:"offset"`
}

// QueryResponse builds a response to an inline Query.
// See also: https://core.telegram.org/bots/api#answerinlinequery
type QueryResponse struct {
	// The ID of the query to which this is a response.
	// It is not necessary to specify this field manually.
	QueryID string `json:"inline_query_id"`

	// The results for the inline query.
	Results []InlineQueryResult `json:"results"`

	// (Optional) The maximum amount of time in seconds that the result
	// of the inline query may be cached on the server.
	CacheTime int `json:"cache_time,omitempty"`

	// (Optional) Pass True, if results may be cached on the server side
	// only for the user that sent the query. By default, results may
	// be returned to any user who sends the same query.
	IsPersonal bool `json:"is_personal"`

	// (Optional) Pass the offset that a client should send in the next
	// query with the same text to receive more results. Pass an empty
	// string if there are no more results or if you don‘t support
	// pagination. Offset length can’t exceed 64 bytes.
	NextOffset string `json:"next_offset"`

	// (Optional) If passed, clients will display a button with specified
	// text that switches the user to a private chat with the bot and sends
	// the bot a start message with the parameter switch_pm_parameter.
	SwitchPMText string `json:"switch_pm_text,omitempty"`

	// (Optional) Parameter for the start message sent to the bot when user
	// presses the switch button.
	SwitchPMParameter string `json:"switch_pm_parameter,omitempty"`
}

// InlineQueryResult represents one result of an inline query.
type InlineQueryResult interface {
	MarshalJSON() ([]byte, error)
	id() (string, error)
}

// hashInlineQueryResult calculates the 64-bit FNV-1 hash of an
// inline query result.
func hashInlineQueryResult(result InlineQueryResult) (string, error) {
	hash, err := hashstructure.Hash(result, inlineQueryHashOptions)
	if err != nil {
		return "", err
	}
	return strconv.FormatUint(hash, 16), nil
}

// Deprecated interface type, superseded by InlineQueryResult.
type Result interface {
	MarshalJSON() ([]byte, error)
}