package codersdk

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

	"github.com/google/uuid"
	"golang.org/x/xerrors"
)

type NotificationsSettings struct {
	NotifierPaused bool `json:"notifier_paused"`
}

type NotificationTemplate struct {
	ID               uuid.UUID `json:"id" format:"uuid"`
	Name             string    `json:"name"`
	TitleTemplate    string    `json:"title_template"`
	BodyTemplate     string    `json:"body_template"`
	Actions          string    `json:"actions" format:""`
	Group            string    `json:"group"`
	Method           string    `json:"method"`
	Kind             string    `json:"kind"`
	EnabledByDefault bool      `json:"enabled_by_default"`
}

type NotificationMethodsResponse struct {
	AvailableNotificationMethods []string `json:"available"`
	DefaultNotificationMethod    string   `json:"default"`
}

type NotificationPreference struct {
	NotificationTemplateID uuid.UUID `json:"id" format:"uuid"`
	Disabled               bool      `json:"disabled"`
	UpdatedAt              time.Time `json:"updated_at" format:"date-time"`
}

// GetNotificationsSettings retrieves the notifications settings, which currently just describes whether all
// notifications are paused from sending.
func (c *Client) GetNotificationsSettings(ctx context.Context) (NotificationsSettings, error) {
	res, err := c.Request(ctx, http.MethodGet, "/api/v2/notifications/settings", nil)
	if err != nil {
		return NotificationsSettings{}, err
	}
	defer res.Body.Close()
	if res.StatusCode != http.StatusOK {
		return NotificationsSettings{}, ReadBodyAsError(res)
	}
	var settings NotificationsSettings
	return settings, json.NewDecoder(res.Body).Decode(&settings)
}

// PutNotificationsSettings modifies the notifications settings, which currently just controls whether all
// notifications are paused from sending.
func (c *Client) PutNotificationsSettings(ctx context.Context, settings NotificationsSettings) error {
	res, err := c.Request(ctx, http.MethodPut, "/api/v2/notifications/settings", settings)
	if err != nil {
		return err
	}
	defer res.Body.Close()

	if res.StatusCode == http.StatusNotModified {
		return nil
	}
	if res.StatusCode != http.StatusOK {
		return ReadBodyAsError(res)
	}
	return nil
}

// UpdateNotificationTemplateMethod modifies a notification template to use a specific notification method, overriding
// the method set in the deployment configuration.
func (c *Client) UpdateNotificationTemplateMethod(ctx context.Context, notificationTemplateID uuid.UUID, method string) error {
	res, err := c.Request(ctx, http.MethodPut,
		fmt.Sprintf("/api/v2/notifications/templates/%s/method", notificationTemplateID),
		UpdateNotificationTemplateMethod{Method: method},
	)
	if err != nil {
		return err
	}
	defer res.Body.Close()

	if res.StatusCode == http.StatusNotModified {
		return nil
	}
	if res.StatusCode != http.StatusOK {
		return ReadBodyAsError(res)
	}
	return nil
}

// GetSystemNotificationTemplates retrieves all notification templates pertaining to internal system events.
func (c *Client) GetSystemNotificationTemplates(ctx context.Context) ([]NotificationTemplate, error) {
	res, err := c.Request(ctx, http.MethodGet, "/api/v2/notifications/templates/system", nil)
	if err != nil {
		return nil, err
	}
	defer res.Body.Close()

	if res.StatusCode != http.StatusOK {
		return nil, ReadBodyAsError(res)
	}

	var templates []NotificationTemplate
	body, err := io.ReadAll(res.Body)
	if err != nil {
		return nil, xerrors.Errorf("read response body: %w", err)
	}

	if err := json.Unmarshal(body, &templates); err != nil {
		return nil, xerrors.Errorf("unmarshal response body: %w", err)
	}

	return templates, nil
}

// GetUserNotificationPreferences retrieves notification preferences for a given user.
func (c *Client) GetUserNotificationPreferences(ctx context.Context, userID uuid.UUID) ([]NotificationPreference, error) {
	res, err := c.Request(ctx, http.MethodGet, fmt.Sprintf("/api/v2/users/%s/notifications/preferences", userID.String()), nil)
	if err != nil {
		return nil, err
	}
	defer res.Body.Close()

	if res.StatusCode != http.StatusOK {
		return nil, ReadBodyAsError(res)
	}

	var prefs []NotificationPreference
	body, err := io.ReadAll(res.Body)
	if err != nil {
		return nil, xerrors.Errorf("read response body: %w", err)
	}

	if err := json.Unmarshal(body, &prefs); err != nil {
		return nil, xerrors.Errorf("unmarshal response body: %w", err)
	}

	return prefs, nil
}

// UpdateUserNotificationPreferences updates notification preferences for a given user.
func (c *Client) UpdateUserNotificationPreferences(ctx context.Context, userID uuid.UUID, req UpdateUserNotificationPreferences) ([]NotificationPreference, error) {
	res, err := c.Request(ctx, http.MethodPut, fmt.Sprintf("/api/v2/users/%s/notifications/preferences", userID.String()), req)
	if err != nil {
		return nil, err
	}
	defer res.Body.Close()

	if res.StatusCode != http.StatusOK {
		return nil, ReadBodyAsError(res)
	}

	var prefs []NotificationPreference
	body, err := io.ReadAll(res.Body)
	if err != nil {
		return nil, xerrors.Errorf("read response body: %w", err)
	}

	if err := json.Unmarshal(body, &prefs); err != nil {
		return nil, xerrors.Errorf("unmarshal response body: %w", err)
	}

	return prefs, nil
}

// GetNotificationDispatchMethods the available and default notification dispatch methods.
func (c *Client) GetNotificationDispatchMethods(ctx context.Context) (NotificationMethodsResponse, error) {
	res, err := c.Request(ctx, http.MethodGet, "/api/v2/notifications/dispatch-methods", nil)
	if err != nil {
		return NotificationMethodsResponse{}, err
	}
	defer res.Body.Close()

	if res.StatusCode != http.StatusOK {
		return NotificationMethodsResponse{}, ReadBodyAsError(res)
	}

	var resp NotificationMethodsResponse
	body, err := io.ReadAll(res.Body)
	if err != nil {
		return NotificationMethodsResponse{}, xerrors.Errorf("read response body: %w", err)
	}

	if err := json.Unmarshal(body, &resp); err != nil {
		return NotificationMethodsResponse{}, xerrors.Errorf("unmarshal response body: %w", err)
	}

	return resp, nil
}

func (c *Client) PostTestNotification(ctx context.Context) error {
	res, err := c.Request(ctx, http.MethodPost, "/api/v2/notifications/test", nil)
	if err != nil {
		return err
	}
	defer res.Body.Close()

	if res.StatusCode != http.StatusNoContent {
		return ReadBodyAsError(res)
	}
	return nil
}

type UpdateNotificationTemplateMethod struct {
	Method string `json:"method,omitempty" example:"webhook"`
}

type UpdateUserNotificationPreferences struct {
	TemplateDisabledMap map[string]bool `json:"template_disabled_map"`
}