package client

import (
	"bytes"
	"context"
	"errors"
	"fmt"
	"io"
	"net/http"
	"net/url"
	"strings"
	"time"

	api "code.zhecent.com/open/shop-crm-agent/internal/api"

	"google.golang.org/protobuf/proto"
)

const (
	apiPath         = "/api/shop/crm-agent/v1"
	maxResponseSize = 16 << 20
)

type Client struct {
	baseURL    string
	token      string
	httpClient *http.Client
}

func New(baseURL, token string, httpClient *http.Client) (*Client, error) {
	baseURL = strings.TrimRight(strings.TrimSpace(baseURL), "/")
	parsed, err := url.Parse(baseURL)
	if err != nil || parsed.Host == "" || (parsed.Scheme != "http" && parsed.Scheme != "https") {
		return nil, errors.New("LIGHTCORE_API_BASE_URL 必须是有效的 http/https URL")
	}
	if strings.TrimSpace(token) == "" {
		return nil, errors.New("LIGHTCORE_SHOP_CRM_AGENT_TOKEN 不能为空")
	}
	if httpClient == nil {
		httpClient = &http.Client{Timeout: 30 * time.Second}
	}
	return &Client{baseURL: baseURL, token: strings.TrimSpace(token), httpClient: httpClient}, nil
}

type responseWithHeader interface {
	proto.Message
	GetHeader() *api.ResponseHeader
}

func doRequest[Req proto.Message, Resp responseWithHeader](ctx context.Context, client *Client, path string, request Req, response Resp) (Resp, error) {
	data, err := proto.Marshal(request)
	if err != nil {
		return response, fmt.Errorf("编码 Protobuf 请求失败: %w", err)
	}
	httpRequest, err := http.NewRequestWithContext(ctx, http.MethodPost, client.baseURL+apiPath+path, bytes.NewReader(data))
	if err != nil {
		return response, err
	}
	httpRequest.Header.Set("Content-Type", "application/x-protobuf")
	httpRequest.Header.Set("Accept", "application/x-protobuf")
	httpRequest.Header.Set("Authorization", "Bearer "+client.token)
	httpResponse, err := client.httpClient.Do(httpRequest)
	if err != nil {
		return response, err
	}
	defer httpResponse.Body.Close()
	body, err := io.ReadAll(io.LimitReader(httpResponse.Body, maxResponseSize+1))
	if err != nil {
		return response, err
	}
	if len(body) > maxResponseSize {
		return response, errors.New("CRM Agent API 响应超过16 MiB限制")
	}
	if err := proto.Unmarshal(body, response); err != nil {
		return response, fmt.Errorf("解析 Protobuf 响应失败（HTTP %d）: %w", httpResponse.StatusCode, err)
	}
	header := response.GetHeader()
	if httpResponse.StatusCode < 200 || httpResponse.StatusCode >= 300 {
		if header != nil && header.Message != "" {
			return response, fmt.Errorf("CRM Agent API HTTP %d: %s", httpResponse.StatusCode, header.Message)
		}
		return response, fmt.Errorf("CRM Agent API HTTP %d", httpResponse.StatusCode)
	}
	if header == nil {
		return response, errors.New("CRM Agent API 响应缺少 ResponseHeader")
	}
	if header.Code != 200 {
		return response, fmt.Errorf("CRM Agent API 错误 %d: %s", header.Code, header.Message)
	}
	return response, nil
}

func (c *Client) CustomerList(ctx context.Context, req *api.CustomerListRequest) (*api.CustomerListResponse, error) {
	return doRequest(ctx, c, "/customers/list", req, &api.CustomerListResponse{})
}
func (c *Client) ProjectList(ctx context.Context, req *api.ProjectListRequest) (*api.ProjectListResponse, error) {
	return doRequest(ctx, c, "/projects/list", req, &api.ProjectListResponse{})
}
func (c *Client) ProjectGet(ctx context.Context, req *api.ProjectGetRequest) (*api.ProjectResponse, error) {
	return doRequest(ctx, c, "/projects/get", req, &api.ProjectResponse{})
}
func (c *Client) ProjectCreate(ctx context.Context, req *api.ProjectCreateRequest) (*api.ProjectResponse, error) {
	return doRequest(ctx, c, "/projects/create", req, &api.ProjectResponse{})
}
func (c *Client) ProjectUpdate(ctx context.Context, req *api.ProjectUpdateRequest) (*api.ProjectResponse, error) {
	return doRequest(ctx, c, "/projects/update", req, &api.ProjectResponse{})
}
func (c *Client) ProjectStatus(ctx context.Context, req *api.ProjectStatusRequest) (*api.ProjectResponse, error) {
	return doRequest(ctx, c, "/projects/status", req, &api.ProjectResponse{})
}
func (c *Client) ProjectDeletePreview(ctx context.Context, req *api.ProjectDeletePreviewRequest) (*api.DeletePreviewResponse, error) {
	return doRequest(ctx, c, "/projects/delete/preview", req, &api.DeletePreviewResponse{})
}
func (c *Client) ProjectDelete(ctx context.Context, req *api.ProjectDeleteRequest) (*api.DeletePreviewResponse, error) {
	return doRequest(ctx, c, "/projects/delete", req, &api.DeletePreviewResponse{})
}

func (c *Client) QuotationList(ctx context.Context, req *api.QuotationListRequest) (*api.QuotationListResponse, error) {
	return doRequest(ctx, c, "/quotations/list", req, &api.QuotationListResponse{})
}
func (c *Client) QuotationGet(ctx context.Context, req *api.QuotationGetRequest) (*api.QuotationResponse, error) {
	return doRequest(ctx, c, "/quotations/get", req, &api.QuotationResponse{})
}
func (c *Client) QuotationCreate(ctx context.Context, req *api.QuotationCreateRequest) (*api.QuotationResponse, error) {
	return doRequest(ctx, c, "/quotations/create", req, &api.QuotationResponse{})
}
func (c *Client) QuotationCopy(ctx context.Context, req *api.QuotationCopyRequest) (*api.QuotationResponse, error) {
	return doRequest(ctx, c, "/quotations/copy", req, &api.QuotationResponse{})
}
func (c *Client) QuotationTitle(ctx context.Context, req *api.QuotationTitleRequest) (*api.QuotationResponse, error) {
	return doRequest(ctx, c, "/quotations/title", req, &api.QuotationResponse{})
}
func (c *Client) QuotationStatus(ctx context.Context, req *api.QuotationStatusRequest) (*api.QuotationResponse, error) {
	return doRequest(ctx, c, "/quotations/status", req, &api.QuotationResponse{})
}
func (c *Client) QuotationLock(ctx context.Context, req *api.QuotationLockRequest) (*api.QuotationResponse, error) {
	return doRequest(ctx, c, "/quotations/lock", req, &api.QuotationResponse{})
}
func (c *Client) QuotationUnlock(ctx context.Context, req *api.QuotationLockRequest) (*api.QuotationResponse, error) {
	return doRequest(ctx, c, "/quotations/unlock", req, &api.QuotationResponse{})
}
func (c *Client) QuotationDeletePreview(ctx context.Context, req *api.QuotationDeletePreviewRequest) (*api.DeletePreviewResponse, error) {
	return doRequest(ctx, c, "/quotations/delete/preview", req, &api.DeletePreviewResponse{})
}
func (c *Client) QuotationDelete(ctx context.Context, req *api.QuotationDeleteRequest) (*api.DeletePreviewResponse, error) {
	return doRequest(ctx, c, "/quotations/delete", req, &api.DeletePreviewResponse{})
}
func (c *Client) CatalogSearch(ctx context.Context, req *api.CatalogSearchRequest) (*api.CatalogSearchResponse, error) {
	return doRequest(ctx, c, "/catalog/search", req, &api.CatalogSearchResponse{})
}

func (c *Client) EditBegin(ctx context.Context, req *api.QuotationEditBeginRequest) (*api.EditSessionResponse, error) {
	return doRequest(ctx, c, "/quotation/edit/begin", req, &api.EditSessionResponse{})
}
func (c *Client) EditCommand(ctx context.Context, req *api.QuotationEditCommandRequest) (*api.QuotationEditCommandResponse, error) {
	return doRequest(ctx, c, "/quotation/edit/command", req, &api.QuotationEditCommandResponse{})
}
func (c *Client) EditPreview(ctx context.Context, req *api.QuotationEditPreviewRequest) (*api.QuotationEditPreviewResponse, error) {
	return doRequest(ctx, c, "/quotation/edit/preview", req, &api.QuotationEditPreviewResponse{})
}
func (c *Client) EditCommit(ctx context.Context, req *api.QuotationEditCommitRequest) (*api.QuotationResponse, error) {
	return doRequest(ctx, c, "/quotation/edit/commit", req, &api.QuotationResponse{})
}
func (c *Client) EditDiscard(ctx context.Context, req *api.QuotationEditDiscardRequest) (*api.EditSessionResponse, error) {
	return doRequest(ctx, c, "/quotation/edit/discard", req, &api.EditSessionResponse{})
}