package mijia

import (
	"context"
	"encoding/json"
	"fmt"
	"strconv"
	"time"
)

const (
	checkNewMessagesURI = "/v2/message/v2/check_new_msg"
	getHomesURI         = "/v2/homeroom/gethome_merged"
	getDevicesURI       = "/home/home_device_list"
	getSharedDevicesURI = "/v2/home/device_list_page"
	getScenesURI        = "/appgateway/miot/appsceneservice/AppSceneService/GetSimpleSceneList"
	getConsumablesURI   = "/v2/home/standard_consumable_items"
	getPropertiesURI    = "/miotspec/prop/get"
	setPropertiesURI    = "/miotspec/prop/set"
	runActionURI        = "/miotspec/action"
)

var getHomesData = map[string]any{
	"fg": true, "fetch_share": true, "fetch_share_dev": true, "fetch_cariot": true,
	"limit": 300, "app_ver": 7, "plat_form": 0,
}

func (client *Client) CheckNewMessages(ctx context.Context, beginAt time.Time) (json.RawMessage, error) {
	result, err := client.request(ctx, checkNewMessagesURI, map[string]int64{"begin_at": beginAt.Unix()}, true)
	if err != nil {
		return nil, fmt.Errorf("check new messages: %w", err)
	}
	return result, nil
}

func (client *Client) GetHomes(ctx context.Context) ([]Home, error) {
	result, err := client.request(ctx, getHomesURI, getHomesData, true)
	if err != nil {
		return nil, fmt.Errorf("get homes: %w", err)
	}
	var response struct {
		Homes []Home `json:"homelist"`
	}
	if err := decodeJSON(result, &response); err != nil {
		return nil, fmt.Errorf("decode %s response: %w", getHomesURI, err)
	}
	return response.Homes, nil
}

func (client *Client) GetDevices(ctx context.Context, homeID string) ([]Device, error) {
	homes, err := client.GetHomes(ctx)
	if err != nil {
		return nil, err
	}
	if homeID != "" {
		owner, err := homeOwner(homes, homeID)
		if err != nil {
			return nil, err
		}
		return client.getDevices(ctx, homeID, owner)
	}

	var devices []Device
	for _, home := range homes {
		homeDevices, err := client.getDevices(ctx, home.ID, home.UID)
		devices = append(devices, homeDevices...)
		if err != nil {
			return devices, fmt.Errorf("get devices for home %s: %w", home.ID, err)
		}
	}
	return devices, nil
}

func (client *Client) getDevices(ctx context.Context, homeID string, owner int64) ([]Device, error) {
	numericHomeID, err := strconv.ParseInt(homeID, 10, 64)
	if err != nil {
		return nil, fmt.Errorf("home id %q must be numeric: %w", homeID, err)
	}
	var devices []Device
	startDID := ""
	seenCursors := map[string]struct{}{startDID: {}}
	for {
		data := map[string]any{
			"home_owner": owner, "home_id": numericHomeID, "limit": 200, "start_did": startDID,
			"get_split_device": true, "support_smart_home": true, "get_cariot_device": true, "get_third_device": true,
		}
		result, err := client.request(ctx, getDevicesURI, data, true)
		if err != nil {
			return nil, fmt.Errorf("request devices for home %s: %w", homeID, err)
		}
		var page struct {
			Devices []Device `json:"device_info"`
			MaxDID  string   `json:"max_did"`
			HasMore bool     `json:"has_more"`
		}
		if err := decodeJSON(result, &page); err != nil {
			return devices, fmt.Errorf("decode %s response for home %s: %w", getDevicesURI, homeID, err)
		}
		for index := range page.Devices {
			page.Devices[index].HomeID = homeID
		}
		devices = append(devices, page.Devices...)
		if !page.HasMore {
			return devices, nil
		}
		if page.MaxDID == "" {
			return devices, fmt.Errorf("paginate %s response for home %s: has_more is true but max_did is empty", getDevicesURI, homeID)
		}
		if _, seen := seenCursors[page.MaxDID]; seen {
			return devices, fmt.Errorf("paginate %s response for home %s: max_did %q repeats or forms a cursor cycle", getDevicesURI, homeID, page.MaxDID)
		}
		seenCursors[page.MaxDID] = struct{}{}
		startDID = page.MaxDID
	}
}

func (client *Client) GetSharedDevices(ctx context.Context) ([]Device, error) {
	data := map[string]any{
		"ssid": "<unknown ssid>", "bssid": "02:00:00:00:00:00", "getVirtualModel": true, "getHuamiDevices": 1,
		"get_split_device": true, "support_smart_home": true, "get_cariot_device": true, "get_third_device": true,
		"get_phone_device": true, "get_miwear_device": true,
	}
	result, err := client.request(ctx, getSharedDevicesURI, data, true)
	if err != nil {
		return nil, fmt.Errorf("get shared devices: %w", err)
	}
	var response struct {
		Devices []Device `json:"list"`
	}
	if err := decodeJSON(result, &response); err != nil {
		return nil, fmt.Errorf("decode %s response: %w", getSharedDevicesURI, err)
	}
	devices := make([]Device, 0, len(response.Devices))
	for _, device := range response.Devices {
		if device.Owner {
			device.HomeID = "shared"
			devices = append(devices, device)
		}
	}
	return devices, nil
}

func (client *Client) GetScenes(ctx context.Context, homeID string) ([]Scene, error) {
	homes, err := client.GetHomes(ctx)
	if err != nil {
		return nil, err
	}
	if homeID != "" {
		owner, err := homeOwner(homes, homeID)
		if err != nil {
			return nil, err
		}
		return client.getScenes(ctx, homeID, owner)
	}
	var scenes []Scene
	for _, home := range homes {
		homeScenes, err := client.getScenes(ctx, home.ID, home.UID)
		if err != nil {
			return nil, fmt.Errorf("get scenes for home %s: %w", home.ID, err)
		}
		scenes = append(scenes, homeScenes...)
	}
	return scenes, nil
}

func (client *Client) getScenes(ctx context.Context, homeID string, owner int64) ([]Scene, error) {
	data := map[string]any{"app_version": 12, "get_type": 2, "home_id": homeID, "owner_uid": owner}
	result, err := client.request(ctx, getScenesURI, data, true)
	if err != nil {
		return nil, fmt.Errorf("request scenes for home %s: %w", homeID, err)
	}
	var response struct {
		Scenes []Scene `json:"manual_scene_info_list"`
	}
	if err := decodeJSON(result, &response); err != nil {
		return nil, fmt.Errorf("decode %s response for home %s: %w", getScenesURI, homeID, err)
	}
	for index := range response.Scenes {
		response.Scenes[index].HomeID = homeID
	}
	return response.Scenes, nil
}

func (client *Client) RunScene(ctx context.Context, sceneID, homeID string) (json.RawMessage, error) {
	homes, err := client.GetHomes(ctx)
	if err != nil {
		return nil, err
	}
	owner, err := homeOwner(homes, homeID)
	if err != nil {
		return nil, err
	}
	data := map[string]any{"scene_id": sceneID, "scene_type": 2, "phone_id": "null", "home_id": homeID, "owner_uid": owner}
	result, err := client.request(ctx, "/appgateway/miot/appsceneservice/AppSceneService/NewRunScene", data, true)
	if err != nil {
		return nil, fmt.Errorf("run scene %s in home %s: %w", sceneID, homeID, err)
	}
	return result, nil
}

func (client *Client) GetConsumables(ctx context.Context, homeID string) ([]Consumable, error) {
	homes, err := client.GetHomes(ctx)
	if err != nil {
		return nil, err
	}
	if homeID != "" {
		owner, err := homeOwner(homes, homeID)
		if err != nil {
			return nil, err
		}
		return client.getConsumables(ctx, homeID, owner)
	}
	var consumables []Consumable
	for _, home := range homes {
		homeConsumables, err := client.getConsumables(ctx, home.ID, home.UID)
		if err != nil {
			return nil, fmt.Errorf("get consumables for home %s: %w", home.ID, err)
		}
		consumables = append(consumables, homeConsumables...)
	}
	return consumables, nil
}

func (client *Client) getConsumables(ctx context.Context, homeID string, owner int64) ([]Consumable, error) {
	numericHomeID, err := strconv.ParseInt(homeID, 10, 64)
	if err != nil {
		return nil, fmt.Errorf("home id %q must be numeric: %w", homeID, err)
	}
	data := map[string]any{"home_id": numericHomeID, "owner_id": owner, "filter_ignore": true}
	result, err := client.request(ctx, getConsumablesURI, data, true)
	if err != nil {
		return nil, fmt.Errorf("request consumables for home %s: %w", homeID, err)
	}
	var response struct {
		Items []struct {
			Consumables []Consumable `json:"consumes_data"`
		} `json:"items"`
	}
	if err := decodeJSON(result, &response); err != nil {
		return nil, fmt.Errorf("decode %s response for home %s: %w", getConsumablesURI, homeID, err)
	}
	if len(response.Items) == 0 {
		return nil, nil
	}
	consumables := response.Items[0].Consumables
	for index := range consumables {
		consumables[index].HomeID = homeID
		var details []json.RawMessage
		if json.Unmarshal(consumables[index].Details, &details) == nil && len(details) == 1 {
			consumables[index].Details = details[0]
		}
	}
	return consumables, nil
}

func (client *Client) GetProperties(ctx context.Context, requests []PropertyRequest) ([]PropertyResult, error) {
	if len(requests) == 0 {
		return []PropertyResult{}, nil
	}
	result, err := client.request(ctx, getPropertiesURI, map[string]any{"params": requests, "datasource": 1}, true)
	if err != nil {
		return nil, fmt.Errorf("get properties: %w", err)
	}
	var properties []PropertyResult
	if err := decodeJSON(result, &properties); err != nil {
		return nil, fmt.Errorf("decode %s response: %w", getPropertiesURI, err)
	}
	return properties, nil
}

func (client *Client) SetProperties(ctx context.Context, requests []PropertySetRequest) ([]PropertyResult, error) {
	if len(requests) == 0 {
		return []PropertyResult{}, nil
	}
	result, err := client.request(ctx, setPropertiesURI, map[string]any{"params": requests}, true)
	if err != nil {
		return nil, fmt.Errorf("set properties: %w", err)
	}
	var properties []PropertyResult
	if err := decodeJSON(result, &properties); err != nil {
		return nil, fmt.Errorf("decode %s response: %w", setPropertiesURI, err)
	}
	for index := range properties {
		properties[index].Message = resultMessage(properties[index].Code, properties[index].Message)
	}
	return properties, nil
}

func (client *Client) RunActions(ctx context.Context, requests []ActionRequest) ([]ActionResult, error) {
	results := make([]ActionResult, 0, len(requests))
	for index, action := range requests {
		result, err := client.request(ctx, runActionURI, map[string]any{"params": action}, true)
		if err != nil {
			return results, fmt.Errorf("run action %d: %w", index, err)
		}
		var actionResult ActionResult
		if err := decodeJSON(result, &actionResult); err != nil {
			return results, fmt.Errorf("decode %s response for action %d: %w", runActionURI, index, err)
		}
		actionResult.Message = resultMessage(actionResult.Code, actionResult.Message)
		results = append(results, actionResult)
	}
	return results, nil
}

func (client *Client) GetStatistics(ctx context.Context, requests []StatisticsRequest) ([]json.RawMessage, error) {
	results := make([]json.RawMessage, 0, len(requests))
	for index, statisticsRequest := range requests {
		result, err := client.request(ctx, "/v2/user/statistics", statisticsRequest, true)
		if err != nil {
			return results, fmt.Errorf("get statistics %d: %w", index, err)
		}
		results = append(results, result)
	}
	return results, nil
}

func homeOwner(homes []Home, homeID string) (int64, error) {
	for _, home := range homes {
		if home.ID == homeID {
			return home.UID, nil
		}
	}
	return 0, &APIError{Code: -1, Message: fmt.Sprintf("未找到 home_id=%s 的家庭信息", homeID)}
}

func resultMessage(code int, message string) string {
	if code == 0 || code == 1 {
		return "成功"
	}
	if knownMessage, ok := errorCodeMessages[code]; ok {
		return knownMessage
	}
	if message != "" {
		return message
	}
	return ErrorMessage(code)
}