package channelpoints

import (
	"context"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"net/url"

	"github.com/google/go-querystring/query"
)

type UpdateCustomRewardParams struct {
	// The ID of the broadcaster that’s updating the reward. This ID must match the user ID found in the OAuth token.
	BroadcasterID string `url:"broadcaster_id"`

	// The ID of the reward to update.
	ID string `url:"id"`
}

type UpdateCustomRewardRequest struct {
	// The custom reward’s title. The title may contain a maximum of 45 characters and it must be unique amongst all of the broadcaster’s custom rewards.
	Title *string `json:"title"`

	// The cost of the reward, in Channel Points.
	// The minimum is 1 point.
	Cost *int64 `json:"cost"`

	// The prompt shown to the viewer when they redeem the reward.
	// Specify a prompt if is_user_input_required is true.
	// The prompt is limited to a maximum of 200 characters.
	Prompt *string `json:"prompt"`

	// A Boolean value that determines whether the reward is enabled. Viewers see only enabled rewards.
	// The default is true.
	IsEnabled *bool `json:"is_enabled"`

	// The background color to use for the reward. Specify the color using Hex format (for example, #9147FF).
	BackgroundColor *string `json:"background_color"`

	// A Boolean value that determines whether the user needs to enter information when redeeming the reward. See the prompt field.
	// The default is false.
	IsUserInputRequired *bool `json:"is_user_input_required"`

	// A Boolean value that determines whether to limit the maximum number of redemptions allowed per live stream (see the max_per_stream field).
	// The default is false.
	IsMaxPerStreamEnabled *bool `json:"is_max_per_stream_enabled"`

	// The maximum number of redemptions allowed per live stream. Applied only if is_max_per_stream_enabled is true.
	// The minimum value is 1.
	MaxPerStream *int `json:"max_per_stream"`

	// A Boolean value that determines whether to limit the maximum number of redemptions allowed per user per stream (see the max_per_user_per_stream field).
	// The default is false.
	IsMaxPerUserPerStreamEnabled *bool `json:"is_max_per_user_per_stream_enabled"`

	// The maximum number of redemptions allowed per user per stream. Applied only if is_max_per_user_per_stream_enabled is true.
	// The minimum value is 1.
	MaxPerUserPerStream *int `json:"max_per_user_per_stream"`

	// A Boolean value that determines whether to apply a cooldown period between redemptions (see the global_cooldown_seconds field for the duration of the cooldown period).
	// The default is false.
	IsGlobalCooldownEnabled *bool `json:"is_global_cooldown_enabled"`

	// The cooldown period, in seconds. Applied only if the is_global_cooldown_enabled field is true.
	// The minimum value is 1; however, the minimum value is 60 for it to be shown in the Twitch UX.
	GlobalCooldownSeconds *int `json:"global_cooldown_seconds"`

	// A Boolean value that determines whether redemptions should be set to FULFILLED status immediately when a reward is redeemed.
	// If false, status is set to UNFULFILLED and follows the normal request queue process.
	// The default is false.
	ShouldRedemptionsSkipRequestQueue *bool `json:"should_redemptions_skip_request_queue"`
}

type UpdateCustomRewardResponse struct {
	// The list contains the single reward that you updated.
	Data []CustomReward `json:"data"`
}

// Updates a custom reward. The app used to create the reward is the only app that may update the reward.
//
// Requires a user access token that includes the channel:manage:redemptions scope.
func (c *ChannelPoints) UpdateCustomReward(ctx context.Context, params *UpdateCustomRewardParams, body *UpdateCustomRewardRequest) (*UpdateCustomRewardResponse, error) {
	v, _ := query.Values(body)
	endpoint := c.baseUrl.ResolveReference(&url.URL{Path: "channel_points/custom_rewards", RawQuery: v.Encode()})

	r, w := io.Pipe()

	go func() {
		if err := json.NewEncoder(w).Encode(body); err != nil {
			w.CloseWithError(err)
		} else {
			w.Close()
		}
	}()

	req, err := http.NewRequestWithContext(ctx, http.MethodPatch, endpoint.String(), r)
	if err != nil {
		return nil, err
	}

	res, err := c.client.Do(req)
	if err != nil {
		return nil, err
	}
	defer res.Body.Close()

	statusOK := res.StatusCode >= 200 && res.StatusCode < 300
	if !statusOK {
		return nil, fmt.Errorf("failed to update custom reward (%d)", res.StatusCode)
	}

	var data UpdateCustomRewardResponse
	if err := json.NewDecoder(res.Body).Decode(&data); err != nil {
		return nil, err
	}

	return &data, nil
}