package integration

import (
	"bytes"
	"chatapp3-golang/internal/config"
	"context"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"net/url"
	"strconv"
	"strings"
)

type Client struct {
	cfg        config.Config
	httpClient *http.Client
}

type UserCredential struct {
	UserID    Int64Value `json:"userId"`
	SysOrigin string `json:"sysOrigin"`
}

type UserProfile struct {
	ID           Int64Value `json:"id"`
	UserAvatar   string     `json:"userAvatar"`
	UserNickname string     `json:"userNickname"`
}

type GoldReceiptCommand struct {
	ReceiptType         string `json:"receiptType"`
	UserID              int64  `json:"userId"`
	SysOrigin           string `json:"sysOrigin"`
	EventID             string `json:"eventId"`
	Remark              string `json:"remark,omitempty"`
	Amount              int64  `json:"amount"`
	CloseDelayAsset     bool   `json:"closeDelayAsset"`
	OpUserType          string `json:"opUserType"`
	CustomizeOrigin     string `json:"customizeOrigin,omitempty"`
	CustomizeOriginDesc string `json:"customizeOriginDesc,omitempty"`
}

type TestGoldReceiptCommand struct {
	ReceiptType     string `json:"receiptType"`
	UserID          int64  `json:"userId"`
	EventType       string `json:"eventType"`
	EventDesc       string `json:"eventDesc"`
	EventID         string `json:"eventId"`
	SysOrigin       string `json:"sysOrigin"`
	Remark          string `json:"remark,omitempty"`
	Amount          int64  `json:"amount"`
	CloseDelayAsset bool   `json:"closeDelayAsset"`
}

type InviteCode struct {
	UserID     Int64Value `json:"userId"`
	InviteCode string `json:"inviteCode"`
	HasBound   bool   `json:"hasBound"`
}

type GrantGoldRequest struct {
	UserID     int64  `json:"userId"`
	SysOrigin  string `json:"sysOrigin"`
	EventID    string `json:"eventId"`
	Origin     string `json:"origin"`
	GoldAmount int64  `json:"goldAmount"`
	Remark     string `json:"remark"`
}

type GrantPropsRequest struct {
	TrackID      int64  `json:"trackId"`
	AcceptUserID int64  `json:"acceptUserId"`
	SysOrigin    string `json:"sysOrigin"`
	Origin       string `json:"origin"`
	SourceGroupID int64 `json:"sourceGroupId"`
}

type resultResponse[T any] struct {
	Code    int    `json:"code"`
	Message string `json:"message"`
	Body    T      `json:"body"`
	Success *bool  `json:"success"`
}

type Int64Value int64

func (v *Int64Value) UnmarshalJSON(data []byte) error {
	raw := strings.TrimSpace(string(data))
	if raw == "" || raw == "null" {
		*v = 0
		return nil
	}
	if strings.HasPrefix(raw, "\"") && strings.HasSuffix(raw, "\"") {
		raw = strings.Trim(raw, "\"")
	}
	parsed, err := strconv.ParseInt(raw, 10, 64)
	if err != nil {
		return err
	}
	*v = Int64Value(parsed)
	return nil
}

func New(cfg config.Config) *Client {
	return &Client{
		cfg: cfg,
		httpClient: &http.Client{
			Timeout: cfg.Timeout,
		},
	}
}

func (c *Client) AuthenticateToken(ctx context.Context, token string) (UserCredential, error) {
	endpoint := c.cfg.JavaAuthBaseURL + "/auth/client/getUserCredentialByToken?token=" + url.QueryEscape(token)
	var resp resultResponse[UserCredential]
	if err := c.getJSON(ctx, endpoint, nil, &resp); err != nil {
		return UserCredential{}, err
	}
	if int64(resp.Body.UserID) == 0 {
		return UserCredential{}, fmt.Errorf("empty credential response")
	}
	return resp.Body, nil
}

func (c *Client) GetDeviceFingerprint(ctx context.Context, userID int64) (string, error) {
	endpoint := c.cfg.JavaDeviceBaseURL + "/user/device/fingerprint?userId=" + url.QueryEscape(strconv.FormatInt(userID, 10))
	var resp resultResponse[string]
	if err := c.getJSON(ctx, endpoint, nil, &resp); err != nil {
		return "", err
	}
	return strings.TrimSpace(resp.Body), nil
}

func (c *Client) EnsureInviteCode(ctx context.Context, authorization string) (InviteCode, error) {
	endpoint := c.cfg.JavaAppBaseURL + "/activity/invite/user/my/invite/code"
	headers := http.Header{}
	if authorization != "" {
		headers.Set("Authorization", authorization)
	}
	var resp InviteCode
	if err := c.getJSON(ctx, endpoint, headers, &resp); err != nil {
		return InviteCode{}, err
	}
	if strings.TrimSpace(resp.InviteCode) == "" {
		return InviteCode{}, fmt.Errorf("invite code response is empty")
	}
	return resp, nil
}

func (c *Client) GrantGold(ctx context.Context, req GrantGoldRequest) error {
	return c.postJSON(ctx, c.cfg.JavaBridgeBaseURL+"/internal/resident-activity/invite/grant-gold", req, nil, nil)
}

func (c *Client) GrantProps(ctx context.Context, req GrantPropsRequest) error {
	return c.postJSON(ctx, c.cfg.JavaBridgeBaseURL+"/internal/resident-activity/invite/grant-props", req, nil, nil)
}

func (c *Client) GetUserProfile(ctx context.Context, userID int64) (UserProfile, error) {
	endpoint := c.cfg.JavaOtherBaseURL + "/user-profile/client/getByUserId?userId=" + url.QueryEscape(strconv.FormatInt(userID, 10))
	var resp resultResponse[UserProfile]
	if err := c.getJSON(ctx, endpoint, nil, &resp); err != nil {
		return UserProfile{}, err
	}
	if int64(resp.Body.ID) == 0 {
		return UserProfile{}, fmt.Errorf("empty user profile response")
	}
	return resp.Body, nil
}

func (c *Client) GetUserLanguage(ctx context.Context, userID int64) (string, error) {
	endpoint := c.cfg.JavaOtherBaseURL + "/user-profile/client/getLanguage?userId=" + url.QueryEscape(strconv.FormatInt(userID, 10))
	var resp resultResponse[string]
	if err := c.getJSON(ctx, endpoint, nil, &resp); err != nil {
		return "", err
	}
	return strings.TrimSpace(resp.Body), nil
}

func (c *Client) MapGoldBalance(ctx context.Context, userIDs []int64) (map[int64]int64, error) {
	endpoint := c.cfg.JavaWalletBaseURL + "/wallet/gold/client/mapBalance"
	var resp resultResponse[map[string]int64]
	if err := c.postJSON(ctx, endpoint, userIDs, nil, &resp); err != nil {
		return nil, err
	}
	result := make(map[int64]int64, len(resp.Body))
	for key, value := range resp.Body {
		userID, err := strconv.ParseInt(key, 10, 64)
		if err != nil {
			continue
		}
		result[userID] = value
	}
	return result, nil
}

func (c *Client) ExistsGoldEvent(ctx context.Context, eventID string) (bool, error) {
	endpoint := c.cfg.JavaWalletBaseURL + "/wallet/gold/client/existsEventId?eventId=" + url.QueryEscape(eventID)
	var resp resultResponse[bool]
	if err := c.getJSON(ctx, endpoint, nil, &resp); err != nil {
		return false, err
	}
	return resp.Body, nil
}

func (c *Client) ChangeGoldBalance(ctx context.Context, cmd GoldReceiptCommand) error {
	endpoint := c.cfg.JavaWalletBaseURL + "/wallet/gold/client/balance/change"
	if err := c.postJSON(ctx, endpoint, cmd, nil, nil); err == nil {
		return nil
	} else if !shouldFallbackToGoldTestEndpoint(err) {
		return err
	}

	// Some local environments only expose the lighter test endpoint payload.
	testCmd := TestGoldReceiptCommand{
		ReceiptType:     cmd.ReceiptType,
		UserID:          cmd.UserID,
		EventType:       cmd.CustomizeOrigin,
		EventDesc:       cmd.CustomizeOriginDesc,
		EventID:         cmd.EventID,
		SysOrigin:       cmd.SysOrigin,
		Remark:          cmd.Remark,
		Amount:          cmd.Amount,
		CloseDelayAsset: cmd.CloseDelayAsset,
	}
	return c.postJSON(ctx, c.cfg.JavaWalletBaseURL+"/wallet/gold/client/balance/change/test", testCmd, nil, nil)
}

func shouldFallbackToGoldTestEndpoint(err error) bool {
	if err == nil {
		return false
	}
	message := strings.ToLower(strings.TrimSpace(err.Error()))
	switch {
	case strings.Contains(message, "status=404"),
		strings.Contains(message, "status=405"),
		strings.Contains(message, "status=501"),
		strings.Contains(message, "connection refused"),
		strings.Contains(message, "no such host"),
		strings.Contains(message, "unsupported protocol"):
		return true
	default:
		return false
	}
}

func (c *Client) getJSON(ctx context.Context, endpoint string, headers http.Header, out any) error {
	req, err := http.NewRequestWithContext(ctx, http.MethodGet, endpoint, nil)
	if err != nil {
		return err
	}
	applyHeaders(req.Header, headers)
	resp, err := c.httpClient.Do(req)
	if err != nil {
		return err
	}
	defer resp.Body.Close()
	return decodeResponse(resp, out)
}

func (c *Client) postJSON(ctx context.Context, endpoint string, payload any, headers http.Header, out any) error {
	data, err := json.Marshal(payload)
	if err != nil {
		return err
	}
	req, err := http.NewRequestWithContext(ctx, http.MethodPost, endpoint, bytes.NewReader(data))
	if err != nil {
		return err
	}
	req.Header.Set("Content-Type", "application/json")
	applyHeaders(req.Header, headers)
	resp, err := c.httpClient.Do(req)
	if err != nil {
		return err
	}
	defer resp.Body.Close()
	return decodeResponse(resp, out)
}

func decodeResponse(resp *http.Response, out any) error {
	body, err := io.ReadAll(resp.Body)
	if err != nil {
		return err
	}
	if resp.StatusCode >= http.StatusBadRequest {
		return fmt.Errorf("java api failed: status=%d body=%s", resp.StatusCode, strings.TrimSpace(string(body)))
	}
	if out == nil || len(body) == 0 {
		return nil
	}
	if err := json.Unmarshal(body, out); err != nil {
		return fmt.Errorf("decode response failed: %w body=%s", err, strings.TrimSpace(string(body)))
	}
	return nil
}

func applyHeaders(dst http.Header, src http.Header) {
	for key, values := range src {
		for _, value := range values {
			dst.Add(key, value)
		}
	}
}