package web

import (
	"errors"
	"fmt"
	"io"
	"net/http"
	"net/url"
	"os"
	"strconv"
	"strings"
	"time"

	"github.com/gin-gonic/gin"

	"cmautobuy/admin/config"
	"cmautobuy/admin/service"
	"cmautobuy/admin/syb"
)

var innerCodeLocation = time.FixedZone("UTC+8", 8*60*60)

// InnerCodeList 渲染独立的档口入库码工作台。
func (h *Handler) InnerCodeList(c *gin.Context) {
	businessDate := strings.TrimSpace(c.Query("date"))
	if _, err := time.Parse("2006-01-02", businessDate); err != nil {
		businessDate = time.Now().In(innerCodeLocation).Format("2006-01-02")
	}
	status := strings.TrimSpace(c.Query("status"))
	keyword := strings.TrimSpace(c.Query("q"))
	result, err := service.ListInnerCodePage(h.db, businessDate, status, keyword, service.ParsePage(c.Query("page")))
	if err != nil {
		fail(c, http.StatusInternalServerError, "读取档口入库码列表失败，请稍后刷新重试。")
		return
	}
	query := url.Values{"date": {businessDate}}
	if result.Status != "" {
		query.Set("status", result.Status)
	}
	if keyword != "" {
		query.Set("q", keyword)
	}
	c.HTML(http.StatusOK, "inner_code/list", page(c, "inner-codes", "档口入库码", gin.H{
		"BusinessDate":  businessDate,
		"StatusFilter":  result.Status,
		"Keyword":       keyword,
		"StatusOptions": service.InnerCodeStatusOptions(),
		"Rows":          result.Rows,
		"HasAny":        result.Counts.Total > 0,
		"IsFiltered":    result.IsFiltered,
		"CurrentPage":   result.Page,
		"Message":       strings.TrimSpace(c.Query("message")),
		"Status":        service.InnerCodeStatusMessage(result),
		"Pagination":    service.NewPaginationView(result.Page, result.TotalPages, query.Encode()),
	}))
}

// InnerCodeImport 接收一次性 xlsx，导入完成后总会删除临时文件。
func (h *Handler) InnerCodeImport(c *gin.Context) {
	fileHeader, err := c.FormFile("file")
	if err != nil {
		fail(c, http.StatusBadRequest, "没有收到 Excel（也可能超过 10MB）；没有导入任何数据。")
		return
	}
	src, err := fileHeader.Open()
	if err != nil {
		fail(c, http.StatusBadRequest, "无法打开上传文件；没有导入任何数据。")
		return
	}
	defer src.Close()
	head := make([]byte, 8)
	n, _ := io.ReadFull(src, head)
	if err := service.ValidateInnerCodeUpload(fileHeader.Filename, fileHeader.Size, head[:n]); err != nil {
		fail(c, http.StatusBadRequest, err.Error()+"；没有导入任何数据。")
		return
	}
	if _, err := src.Seek(0, io.SeekStart); err != nil {
		fail(c, http.StatusInternalServerError, "读取上传文件失败；没有导入任何数据。")
		return
	}
	uploadDir, err := config.SubDir("uploads")
	if err != nil {
		fail(c, http.StatusInternalServerError, "无法准备临时上传目录；没有导入任何数据。")
		return
	}
	tmp, err := os.CreateTemp(uploadDir, "inner-code-*.xlsx")
	if err != nil {
		fail(c, http.StatusInternalServerError, "无法保存临时上传文件；没有导入任何数据。")
		return
	}
	tmpPath := tmp.Name()
	defer os.Remove(tmpPath)
	if _, err := io.Copy(tmp, src); err != nil {
		tmp.Close()
		fail(c, http.StatusInternalServerError, "保存临时上传文件失败；没有导入任何数据。")
		return
	}
	if err := tmp.Close(); err != nil {
		fail(c, http.StatusInternalServerError, "保存临时上传文件失败；没有导入任何数据。")
		return
	}
	result, err := service.ImportInnerCodeExcel(h.db, tmpPath, fileHeader.Filename, currentUser(c).UserID)
	if err != nil {
		if service.IsInvalidInnerCodeImport(err) {
			fail(c, http.StatusBadRequest, err.Error()+"；请修正文件后重新导入。")
			return
		}
		fail(c, http.StatusInternalServerError, "档口入库码写库失败，本次导入已整体回滚，请稍后重试。")
		return
	}
	message := fmt.Sprintf("导入完成：业务日期 %s，读取 %d 行，新增 %d 条，更新 %d 条，恢复 %d 条，同业务键合并 %d 行。",
		result.BusinessDate, result.TotalRows, result.CreatedCount, result.UpdatedCount, result.RestoredCount, result.MergedRows)
	h.innerCodeRedirect(c, result.BusinessDate, "", "", 1, message)
}

// InnerCodeDelete 软删除当前页已选记录；不撤销任何顺运宝远端操作。
func (h *Handler) InnerCodeDelete(c *gin.Context) {
	businessDate, status, keyword := c.PostForm("date"), c.PostForm("status"), c.PostForm("q")
	pageNumber := service.ParsePage(c.PostForm("page"))
	ids := parseInnerCodeIDs(c.PostFormArray("ids"))
	count, err := service.DeleteInnerCodes(h.db, ids, currentUser(c).UserID, time.Now())
	if err != nil {
		h.innerCodeRedirect(c, businessDate, status, keyword, pageNumber, "删除失败："+err.Error()+"；没有部分删除，请刷新后重试。")
		return
	}
	h.innerCodeRedirect(c, businessDate, status, keyword, pageNumber,
		fmt.Sprintf("已删除 %d 条档口入库码记录；顺运宝已写入的快递单号不会撤销。重新导入相同数据可恢复。", count))
}

// InnerCodeMatch 读取远端最新详情并保存只读规划，不执行任何回写。
func (h *Handler) InnerCodeMatch(c *gin.Context) {
	businessDate := strings.TrimSpace(c.PostForm("date"))
	status, keyword := c.PostForm("status"), c.PostForm("q")
	pageNumber := service.ParsePage(c.PostForm("page"))
	if _, err := time.Parse("2006-01-02", businessDate); err != nil {
		h.innerCodeRedirect(c, time.Now().In(innerCodeLocation).Format("2006-01-02"), status, keyword, 1, "业务日期无效，没有执行匹配。")
		return
	}
	ids := parseInnerCodeIDs(c.PostFormArray("ids"))
	if len(ids) == 0 {
		h.innerCodeRedirect(c, businessDate, status, keyword, pageNumber, "请先勾选要匹配的记录。")
		return
	}
	if len(ids) > service.PageSize {
		h.innerCodeRedirect(c, businessDate, status, keyword, pageNumber, "一次最多匹配当前页 20 条记录，请刷新后重新勾选。")
		return
	}
	cfg, err := config.Load()
	if err != nil {
		h.innerCodeRedirect(c, businessDate, status, keyword, pageNumber, "顺运宝配置不可用，没有执行匹配。")
		return
	}
	client, err := syb.New(cfg.Syb.BaseURL)
	if err != nil {
		h.innerCodeRedirect(c, businessDate, status, keyword, pageNumber, "顺运宝地址配置有误，没有执行匹配。")
		return
	}
	autoLoggedIn, message := ensureInnerCodeMatchSession(
		func() error { return service.EnsureSybSession(h.db, client, cfg.Syb.Username, time.Now()) },
		func() (string, bool) { return h.attemptSybAutoLogin(c, client, *cfg) },
	)
	if message != "" {
		h.innerCodeRedirect(c, businessDate, status, keyword, pageNumber, message)
		return
	}
	result, err := service.PlanInnerCodeRecords(c.Request.Context(), h.db, client, businessDate, ids)
	if err != nil {
		h.innerCodeRedirect(c, businessDate, status, keyword, pageNumber, "匹配失败："+err.Error())
		return
	}
	message = fmt.Sprintf("匹配完成：处理 %d 条，可回写 %d 条，已存在 %d 条，跳过 %d 条，失败 %d 条。",
		result.Total, result.Ready, result.AlreadyFilled, result.Skipped, result.Failed)
	if autoLoggedIn {
		message = "顺运宝自动登录成功；" + message
	}
	h.innerCodeRedirect(c, businessDate, status, keyword, pageNumber, message)
}

// ensureInnerCodeMatchSession 只负责“检查缓存 → 必要时自动登录”的编排。
// 自动登录成功后调用方继续使用同一个 client；这里绝不启动顺运宝同步。
func ensureInnerCodeMatchSession(checkSession func() error, autoLogin func() (string, bool)) (bool, string) {
	err := checkSession()
	if err == nil {
		return false, ""
	}
	if !errors.Is(err, service.ErrSybLoginRequired) {
		return false, "校验顺运宝会话失败，没有执行匹配。"
	}
	reason, ok := autoLogin()
	if ok {
		return true, ""
	}
	reason = strings.TrimSpace(reason)
	if reason == "" {
		reason = "未配置验证码识别服务，无法自动登录"
	}
	return false, "顺运宝自动登录未完成：" + reason + "；没有执行匹配，请到“顺运宝数据”页面完成登录。"
}

// InnerCodeApply 在操作员确认后逐条执行安全回写。
func (h *Handler) InnerCodeApply(c *gin.Context) {
	businessDate, status, keyword := c.PostForm("date"), c.PostForm("status"), c.PostForm("q")
	pageNumber := service.ParsePage(c.PostForm("page"))
	ids := parseInnerCodeIDs(c.PostFormArray("ids"))
	client, message := h.innerCodeSybClient()
	if message != "" {
		h.innerCodeRedirect(c, businessDate, status, keyword, pageNumber, message)
		return
	}
	result, err := service.ApplyInnerCodes(c.Request.Context(), h.db, client, ids, currentUser(c).UserID)
	if err != nil {
		h.innerCodeRedirect(c, businessDate, status, keyword, pageNumber, "回写未完成："+err.Error())
		return
	}
	message = fmt.Sprintf("回写完成：选择 %d 条，成功 %d 条，已存在 %d 条，跳过 %d 条，失败 %d 条，需核对 %d 条。",
		result.Requested, result.Updated, result.AlreadyFilled, result.Skipped, result.Failed, result.NeedsCheck)
	h.innerCodeRedirect(c, businessDate, status, keyword, pageNumber, message)
}

func parseInnerCodeIDs(rawIDs []string) []int64 {
	ids := make([]int64, 0, len(rawIDs))
	seen := make(map[int64]bool, len(rawIDs))
	for _, raw := range rawIDs {
		id, err := strconv.ParseInt(strings.TrimSpace(raw), 10, 64)
		if err != nil || id <= 0 || seen[id] {
			continue
		}
		seen[id] = true
		ids = append(ids, id)
	}
	return ids
}

// InnerCodeRecheck 只重新读取未知结果，绝不再次发送删除或写入。
func (h *Handler) InnerCodeRecheck(c *gin.Context) {
	businessDate, status, keyword := c.PostForm("date"), c.PostForm("status"), c.PostForm("q")
	pageNumber := service.ParsePage(c.PostForm("page"))
	id, err := strconv.ParseInt(strings.TrimSpace(c.PostForm("id")), 10, 64)
	if err != nil || id <= 0 {
		h.innerCodeRedirect(c, businessDate, status, keyword, pageNumber, "记录编号无效，没有执行核对。")
		return
	}
	client, message := h.innerCodeSybClient()
	if message != "" {
		h.innerCodeRedirect(c, businessDate, status, keyword, pageNumber, message)
		return
	}
	_, message, err = service.RecheckInnerCode(c.Request.Context(), h.db, client, id)
	if err != nil {
		message = "重新核对失败：" + err.Error()
	}
	h.innerCodeRedirect(c, businessDate, status, keyword, pageNumber, message)
}

func (h *Handler) innerCodeSybClient() (*syb.Client, string) {
	cfg, err := config.Load()
	if err != nil {
		return nil, "顺运宝配置不可用，没有发送远端请求。"
	}
	client, err := syb.New(cfg.Syb.BaseURL)
	if err != nil {
		return nil, "顺运宝地址配置有误，没有发送远端请求。"
	}
	if err := service.EnsureSybSession(h.db, client, cfg.Syb.Username, time.Now()); err != nil {
		if errors.Is(err, service.ErrSybLoginRequired) {
			return nil, "顺运宝会话已过期，请先到“顺运宝数据”页面登录。"
		}
		return nil, "校验顺运宝会话失败，没有发送远端请求。"
	}
	return client, ""
}

func (h *Handler) innerCodeRedirect(c *gin.Context, businessDate, status, keyword string, pageNumber int, message string) {
	values := url.Values{"date": {businessDate}, "page": {strconv.Itoa(pageNumber)}, "message": {message}}
	if strings.TrimSpace(status) != "" {
		values.Set("status", strings.TrimSpace(status))
	}
	if strings.TrimSpace(keyword) != "" {
		values.Set("q", strings.TrimSpace(keyword))
	}
	c.Redirect(http.StatusSeeOther, "/inner-codes?"+values.Encode())
}