package analytics

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

	"github.com/google/go-querystring/query"
	"go.fifitido.net/twitch/api/types"
)

type GetExtensionAnalyticsParams struct {
	// The extension's client ID. If specified, the response contains a report for the specified extension.
	// If not specified, the response includes a report for each extension that the authenticated user owns.
	ExtensionID *string `url:"extension_id,omitempty"`

	// The type of analytics report to get. Possible values are:
	//
	// - overview_v2
	Type *string `url:"type,omitempty"`

	// The reporting window's start date, in RFC3339 format. Set the time portion to zeroes (for example, 2021-10-22T00:00:00Z).
	//
	// The start date must be on or after January 31, 2018. If you specify an earlier date, the API ignores it and uses January 31, 2018.
	// If you specify a start date, you must specify an end date. If you don't specify a start and end date,
	// the report includes all available data since January 31, 2018.
	//
	// The report contains one row of data for each day in the reporting window.
	StartedAt *time.Time `url:"started_at,omitempty"`

	// The reporting window's end date, in RFC3339 format. Set the time portion to zeroes (for example, 2021-10-27T00:00:00Z).
	// The report is inclusive of the end date.
	//
	// Specify an end date only if you provide a start date. Because it can take up to two days for the data to be available,
	// you must specify an end date that's earlier than today minus one to two days.
	// If not, the API ignores your end date and uses an end date that is today minus one to two days.
	EndedAt *time.Time `url:"ended_at,omitempty"`

	// The maximum number of report URLs to return per page in the response.
	// The minimum page size is 1 URL per page and the maximum is 100 URLs per page. The default is 20.
	//
	// NOTE: While you may specify a maximum value of 100, the response will contain at most 20 URLs per page.
	First *int `url:"first,omitempty"`

	// The cursor used to get the next page of results. The Pagination object in the response contains the cursor’s value.
	// Read More: https://dev.twitch.tv/docs/api/guide#pagination
	//
	// This parameter is ignored if the extension_id parameter is set.
	After *types.Cursor `url:"after,omitempty"`
}

type GetExtensionAnalyticsResponse struct {
	// A list of reports. The reports are returned in no particular order; however, the data within each report is in ascending order by date (newest first).
	// The report contains one row of data per day of the reporting window; the report contains rows for only those days that the extension was used.
	// The array is empty if there are no reports.
	Data []ExtensionAnalyticsReport `json:"data"`

	// Contains the information used to page through the list of results. The object is empty if there are no more pages left to page through.
	// Read More: https://dev.twitch.tv/docs/api/guide#pagination
	Pagination types.Pagination `json:"pagination"`
}

type ExtensionAnalyticsReport struct {
	// An ID that identifies the extension that the report was generated for.
	ExtensionID string `json:"extension_id"`

	// The URL that you use to download the report. The URL is valid for 5 minutes.
	URL string `json:"URL"`

	// The type of report.
	Type string `json:"type"`

	// The reporting window’s start and end dates, in RFC3339 format.
	DateRange types.DateRange `json:"date_range"`
}

// Gets an analytics report for one or more extensions. The response contains the URLs used to download the reports (CSV files).
// Learn More: https://dev.twitch.tv/docs/insights
//
// Requires a user access token that includes the analytics:read:extensions scope.
func (e *Analytics) GetExtensionAnalytics(ctx context.Context, params GetExtensionAnalyticsParams) (*GetExtensionAnalyticsResponse, error) {
	v, _ := query.Values(params)
	endpoint := e.baseUrl.ResolveReference(&url.URL{Path: "analytics/extensions", RawQuery: v.Encode()})

	req, err := http.NewRequest(http.MethodGet, endpoint.String(), nil)
	if err != nil {
		return nil, err
	}

	res, err := e.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 get extension analytics (%d)", res.StatusCode)
	}

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

	return &data, nil
}