package wmsstock

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"time"
)

// Client WMS 内部 API 客户端（X-API-TOKEN 写死 token 保护）
type Client struct {
	BaseURL string
	Token   string
	HTTP    *http.Client
}

func New(baseURL, token string) *Client {
	return &Client{
		BaseURL: baseURL,
		Token:   token,
		HTTP:    &http.Client{Timeout: 15 * time.Second},
	}
}

// wmsResp WMS 统一响应 {code,message,data}
type wmsResp struct {
	Code    int             `json:"code"`
	Message string          `json:"message"`
	Data    json.RawMessage `json:"data"`
}

func (c *Client) call(method, path string, body any) (json.RawMessage, error) {
	var rd io.Reader
	if body != nil {
		b, err := json.Marshal(body)
		if err != nil {
			return nil, err
		}
		rd = bytes.NewReader(b)
	}
	req, err := http.NewRequest(method, c.BaseURL+path, rd)
	if err != nil {
		return nil, err
	}
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("X-API-TOKEN", c.Token)
	resp, err := c.HTTP.Do(req)
	if err != nil {
		return nil, fmt.Errorf("WMS 不可达(%s): %w", path, err)
	}
	defer resp.Body.Close()
	raw, _ := io.ReadAll(resp.Body)
	var wr wmsResp
	if err := json.Unmarshal(raw, &wr); err != nil {
		return nil, fmt.Errorf("WMS 响应解析失败(%s): %s", path, truncate(string(raw), 200))
	}
	if wr.Code != 0 {
		return nil, fmt.Errorf("WMS 返回错误(%s): %s", path, wr.Message)
	}
	return wr.Data, nil
}

func truncate(s string, n int) string {
	if len(s) > n {
		return s[:n]
	}
	return s
}

// ============ 数据结构（与 C 的内部接口契约对齐）============

type CheckItem struct {
	MaterialCode string `json:"materialCode"`
	Qty          int    `json:"qty"`
}

type LockItem struct {
	MaterialCode string `json:"materialCode"`
	BatchNo      string `json:"batchNo,omitempty"`
	Sn           string `json:"sn,omitempty"`
	Qty          int    `json:"qty"`
}

type LedgerItem struct {
	MaterialCode string `json:"materialCode"`
	MaterialName string `json:"materialName"`
	TotalQty     int    `json:"totalQty"`
}

// ============ 业务方法 ============

// CheckStock 批量校验库存是否充足
func (c *Client) CheckStock(items []CheckItem) (json.RawMessage, error) {
	return c.call(http.MethodPost, "/api/internal/stock/check", map[string]any{"items": items})
}

// LockStock 锁定库存（结构件锁批次量 / 精密件逐 SN）
func (c *Client) LockStock(orderNo string, items []LockItem) (json.RawMessage, error) {
	return c.call(http.MethodPost, "/api/internal/stock/lock", map[string]any{"orderNo": orderNo, "items": items})
}

// UnlockStock 解锁库存
func (c *Client) UnlockStock(orderNo string, lockIds []int) (json.RawMessage, error) {
	return c.call(http.MethodPost, "/api/internal/stock/unlock", map[string]any{"orderNo": orderNo, "lockIds": lockIds})
}

// Deduct 出库扣减（领料出库，累计≤台账需求）
func (c *Client) Deduct(req map[string]any) (json.RawMessage, error) {
	return c.call(http.MethodPost, "/api/internal/stock/deduct", req)
}

// QueryStock 库存查询（FIFO 分配用）
func (c *Client) QueryStock(materialCode, zoneCode string) (json.RawMessage, error) {
	return c.call(http.MethodGet, "/api/internal/stock/query?materialCode="+materialCode+"&zoneCode="+zoneCode+"&pageSize=500", nil)
}

// LedgerSync 同步工单 BOM 台账到 WMS
func (c *Client) LedgerSync(orderNo, productCode string, items []LedgerItem) (json.RawMessage, error) {
	return c.call(http.MethodPost, "/api/internal/ledger/sync", map[string]any{
		"orderNo": orderNo, "productCode": productCode, "items": items,
	})
}

// SemiInbound 半成品入库暂存
func (c *Client) SemiInbound(sn, materialCode, completedProcess, zoneCode, orderNo, operator string) (json.RawMessage, error) {
	return c.call(http.MethodPost, "/api/internal/semi/inbound", map[string]any{
		"sn": sn, "materialCode": materialCode, "completedProcess": completedProcess,
		"zoneCode": zoneCode, "orderNo": orderNo, "operator": operator,
	})
}

// SemiOutbound 半成品出库重上线
func (c *Client) SemiOutbound(sn, zoneCode, operator string) (json.RawMessage, error) {
	return c.call(http.MethodPost, "/api/internal/semi/outbound", map[string]any{
		"sn": sn, "zoneCode": zoneCode, "operator": operator,
	})
}

// DisplayOverview 库存总览（大屏用）
func (c *Client) DisplayOverview() (json.RawMessage, error) {
	return c.call(http.MethodGet, "/api/internal/display/overview", nil)
}