package controllers

import (
	"encoding/json"
	"io"
	"strconv"
	"strings"
	"time"

	"server/models"

	"github.com/beego/beego/v2/client/orm"
	beego "github.com/beego/beego/v2/server/web"
)

// BackendCrmUnitController CRM 基本设置-计量单位（产品等单位下拉取自该表）
type BackendCrmUnitController struct {
	beego.Controller
}

type crmUnitPayload struct {
	Name   string `json:"name"`
	Code   string `json:"code"`
	Sort   int    `json:"sort"`
	Status int8   `json:"status"`
	Remark string `json:"remark"`
}

// crmUnitItem 列表项：单位信息 + 引用数（引用该单位的产品数量）
type crmUnitItem struct {
	models.TenantCrmUnit
	UsedCount int64 `json:"used_count"`
}

// crmUnitUsageRow 单位引用统计（按产品表 unit 分组计数）
type crmUnitUsageRow struct {
	Unit string `orm:"column(unit)"`
	Cnt  int64  `orm:"column(cnt)"`
}

// crmDefaultUnits 默认单位：租户首次使用单位设置时自动写入（顺序即排序）
var crmDefaultUnits = []struct {
	Name string
	Code string
}{
	{"套", "SET"},
	{"台", "TAI"},
	{"个", "PCS"},
	{"件", "PIECE"},
	{"批", "BATCH"},
	{"次", "TIME"},
	{"项", "ITEM"},
	{"人月", "PM"},
	{"人天", "PD"},
	{"年", "YEAR"},
	{"月", "MONTH"},
	{"米", "M"},
	{"平方米", "SQM"},
	{"吨", "TON"},
	{"千克", "KG"},
	{"箱", "BOX"},
}

// crmEnsureDefaultUnits 租户首次使用（从未有过任何单位记录，含已软删除的）时写入默认单位。
// 用户手动清空后不再自动补，避免越删越有；需要恢复时用「恢复默认单位」接口。
// 已有记录时顺带修复存量默认单位的 is_default 标记（历史数据升级）。
func crmEnsureDefaultUnits(tenantID string) {
	if models.Orm == nil || strings.TrimSpace(tenantID) == "" {
		return
	}
	cnt, err := models.Orm.QueryTable(new(models.TenantCrmUnit)).
		Filter("tenant_id", tenantID).Count()
	if err != nil {
		return
	}
	if cnt == 0 {
		crmInsertDefaultUnits(tenantID, nil)
		return
	}
	crmMarkDefaultUnits(tenantID)
}

// crmMarkDefaultUnits 将默认清单中已存在的存量单位标记为 is_default=1（历史数据升级自修复，
// 避免早期写入的默认单位因未打标而被误编辑/删除）。
func crmMarkDefaultUnits(tenantID string) {
	names := make([]string, 0, len(crmDefaultUnits))
	for _, u := range crmDefaultUnits {
		names = append(names, u.Name)
	}
	if len(names) == 0 {
		return
	}
	_, _ = models.Orm.QueryTable(new(models.TenantCrmUnit)).
		Filter("tenant_id", tenantID).
		Filter("name__in", names).
		Update(orm.Params{"is_default": 1})
}

// crmInsertDefaultUnits 写入默认单位，跳过已存在的名称（existing 为已存在单位名集合）。
// 返回新增数量。
func crmInsertDefaultUnits(tenantID string, existing map[string]bool) int {
	now := time.Now()
	added := 0
	for i, u := range crmDefaultUnits {
		if existing != nil && existing[u.Name] {
			continue
		}
		row := models.TenantCrmUnit{
			TenantID:   tenantID,
			Name:       u.Name,
			Code:       u.Code,
			Sort:       i + 1,
			Status:     1,
			IsDefault:  1, // 系统默认单位：不可编辑、不可删除
			CreateTime: now,
			UpdateTime: now,
		}
		if _, err := models.Orm.Insert(&row); err == nil {
			added++
		}
	}
	return added
}

// crmInitDefaultUnits 补充缺失的默认单位：
//   - 已存在（启用/停用）的单位不动；
//   - 已软删除的同名单位直接恢复（清 delete_time）并置为启用。
//
// 返回本次新增/恢复的数量。
func crmInitDefaultUnits(tenantID string) int {
	var rows []models.TenantCrmUnit
	_, _ = models.Orm.QueryTable(new(models.TenantCrmUnit)).
		Filter("tenant_id", tenantID).All(&rows)

	existing := make(map[string]bool, len(rows))
	deleted := make(map[string]uint64, len(rows))
	for _, r := range rows {
		if r.DeleteTime != nil {
			deleted[r.Name] = r.ID
			continue
		}
		existing[r.Name] = true
	}

	now := time.Now()
	table := new(models.TenantCrmUnit).TableName()
	added := 0
	for i, u := range crmDefaultUnits {
		if existing[u.Name] {
			continue
		}
		if id, ok := deleted[u.Name]; ok {
			if _, err := models.Orm.Raw("UPDATE "+table+
				" SET delete_time = NULL, status = 1, is_default = 1, sort = ?, update_time = ? WHERE id = ?",
				i+1, now, id).Exec(); err == nil {
				existing[u.Name] = true
				added++
			}
			continue
		}
		row := models.TenantCrmUnit{
			TenantID:   tenantID,
			Name:       u.Name,
			Code:       u.Code,
			Sort:       i + 1,
			Status:     1,
			IsDefault:  1, // 系统默认单位：不可编辑、不可删除
			CreateTime: now,
			UpdateTime: now,
		}
		if _, err := models.Orm.Insert(&row); err == nil {
			existing[u.Name] = true
			added++
		}
	}
	return added
}

// crmUnitUsage 统计各单位的引用数（引用该单位且未删除的产品数量）。
func crmUnitUsage(tenantID string) map[string]int64 {
	usage := make(map[string]int64, len(crmDefaultUnits))
	if models.Orm == nil {
		return usage
	}
	var rows []crmUnitUsageRow
	_, err := models.Orm.Raw("SELECT unit, COUNT(*) AS cnt FROM "+
		new(models.TenantCrmProduct).TableName()+
		" WHERE tenant_id = ? AND delete_time IS NULL AND unit <> '' GROUP BY unit",
		tenantID).QueryRows(&rows)
	if err != nil {
		return usage
	}
	for _, r := range rows {
		usage[strings.TrimSpace(r.Unit)] = r.Cnt
	}
	return usage
}

// List GET /backend/crm/unit/list
func (c *BackendCrmUnitController) List() {
	claims, err := pipelineClaims(&c.Controller)
	if err != nil {
		pipelineErr(&c.Controller, 401, 401, err.Error())
		return
	}
	page, _ := c.GetInt("page", 1)
	pageSize, _ := c.GetInt("pageSize", 20)
	if page < 1 {
		page = 1
	}
	if pageSize < 1 || pageSize > 200 {
		pageSize = 20
	}
	keyword := strings.TrimSpace(c.GetString("keyword"))
	status := strings.TrimSpace(c.GetString("status"))

	tenantID := pipelineTenantID(claims)
	crmEnsureDefaultUnits(tenantID)

	cond := orm.NewCondition().And("tenant_id", tenantID).And("delete_time__isnull", true)
	if keyword != "" {
		kw := orm.NewCondition().
			Or("name__contains", keyword).
			Or("code__contains", keyword)
		cond = cond.AndCond(kw)
	}
	if status != "" {
		cond = cond.And("status", status)
	}
	qs := models.Orm.QueryTable(new(models.TenantCrmUnit)).SetCond(cond)

	total, _ := qs.Count()
	items := make([]crmUnitItem, 0, 8)
	if total > 0 {
		usage := crmUnitUsage(tenantID)
		var list []models.TenantCrmUnit
		_, _ = qs.OrderBy("sort", "id").Offset((page - 1) * pageSize).Limit(pageSize).All(&list)
		for _, row := range list {
			items = append(items, crmUnitItem{TenantCrmUnit: row, UsedCount: usage[row.Name]})
		}
	}
	pipelineOk(&c.Controller, map[string]interface{}{
		"list": items, "total": total, "page": page, "pageSize": pageSize,
	})
}

// All GET /backend/crm/unit/all —— 下拉数据源：仅返回启用中的单位
func (c *BackendCrmUnitController) All() {
	claims, err := pipelineClaims(&c.Controller)
	if err != nil {
		pipelineErr(&c.Controller, 401, 401, err.Error())
		return
	}
	tenantID := pipelineTenantID(claims)
	crmEnsureDefaultUnits(tenantID)

	var list []models.TenantCrmUnit
	_, _ = models.Orm.QueryTable(new(models.TenantCrmUnit)).
		Filter("tenant_id", tenantID).
		Filter("delete_time__isnull", true).
		Filter("status", 1).
		OrderBy("sort", "id").Limit(200).All(&list)
	pipelineOk(&c.Controller, map[string]interface{}{"list": list})
}

// Detail GET /backend/crm/unit/:id
func (c *BackendCrmUnitController) Detail() {
	claims, err := pipelineClaims(&c.Controller)
	if err != nil {
		pipelineErr(&c.Controller, 401, 401, err.Error())
		return
	}
	id, _ := strconv.ParseUint(c.Ctx.Input.Param(":id"), 10, 64)
	if id == 0 {
		pipelineErr(&c.Controller, 400, 400, "无效的ID")
		return
	}
	var row models.TenantCrmUnit
	if err := models.Orm.QueryTable(new(models.TenantCrmUnit)).
		Filter("id", id).Filter("tenant_id", pipelineTenantID(claims)).
		Filter("delete_time__isnull", true).One(&row); err != nil {
		pipelineErr(&c.Controller, 404, 404, "单位未找到")
		return
	}
	pipelineOk(&c.Controller, row)
}

// Create POST /backend/crm/unit
func (c *BackendCrmUnitController) Create() {
	claims, err := pipelineClaims(&c.Controller)
	if err != nil {
		pipelineErr(&c.Controller, 401, 401, err.Error())
		return
	}
	raw, _ := io.ReadAll(c.Ctx.Request.Body)
	var p crmUnitPayload
	if err := json.Unmarshal(raw, &p); err != nil {
		pipelineErr(&c.Controller, 400, 400, "参数错误")
		return
	}
	name := strings.TrimSpace(p.Name)
	if name == "" {
		pipelineErr(&c.Controller, 400, 400, "单位名称不能为空")
		return
	}
	status := p.Status
	if status != 0 && status != 1 {
		status = 1
	}
	tenantID := pipelineTenantID(claims)
	now := time.Now()

	// 同租户下单位名称唯一：命中已存在的记录时，若已软删除则「复活」复用，避免唯一索引冲突
	var old models.TenantCrmUnit
	if err := models.Orm.QueryTable(new(models.TenantCrmUnit)).
		Filter("tenant_id", tenantID).Filter("name", name).One(&old); err == nil {
		if old.DeleteTime == nil {
			pipelineErr(&c.Controller, 400, 400, "单位名称已存在")
			return
		}
		if _, err := models.Orm.Raw("UPDATE "+new(models.TenantCrmUnit).TableName()+
			" SET code = ?, sort = ?, status = ?, remark = ?, update_time = ?, delete_time = NULL WHERE id = ?",
			strings.TrimSpace(p.Code), p.Sort, status, strings.TrimSpace(p.Remark), now, old.ID).Exec(); err != nil {
			pipelineErr(&c.Controller, 500, 500, "创建失败: "+err.Error())
			return
		}
		pipelineOk(&c.Controller, map[string]interface{}{"id": old.ID})
		return
	}

	row := models.TenantCrmUnit{
		TenantID:     tenantID,
		Name:         name,
		Code:         strings.TrimSpace(p.Code),
		Sort:         p.Sort,
		Status:       status,
		Remark:       strings.TrimSpace(p.Remark),
		CreateUserID: pipelineUID(claims),
		CreateTime:   now,
		UpdateTime:   now,
	}
	id, err := models.Orm.Insert(&row)
	if err != nil {
		if strings.Contains(err.Error(), "uk_tenant_name") {
			pipelineErr(&c.Controller, 400, 400, "单位名称已存在")
			return
		}
		pipelineErr(&c.Controller, 500, 500, "创建失败: "+err.Error())
		return
	}
	pipelineOk(&c.Controller, map[string]interface{}{"id": id})
}

// Update PUT /backend/crm/unit/:id
func (c *BackendCrmUnitController) Update() {
	claims, err := pipelineClaims(&c.Controller)
	if err != nil {
		pipelineErr(&c.Controller, 401, 401, err.Error())
		return
	}
	id, _ := strconv.ParseUint(c.Ctx.Input.Param(":id"), 10, 64)
	if id == 0 {
		pipelineErr(&c.Controller, 400, 400, "无效的ID")
		return
	}
	raw, _ := io.ReadAll(c.Ctx.Request.Body)
	var p crmUnitPayload
	if err := json.Unmarshal(raw, &p); err != nil {
		pipelineErr(&c.Controller, 400, 400, "参数错误")
		return
	}
	name := strings.TrimSpace(p.Name)
	if name == "" {
		pipelineErr(&c.Controller, 400, 400, "单位名称不能为空")
		return
	}
	tenantID := pipelineTenantID(claims)
	var row models.TenantCrmUnit
	if err := models.Orm.QueryTable(new(models.TenantCrmUnit)).
		Filter("id", id).Filter("tenant_id", tenantID).
		Filter("delete_time__isnull", true).One(&row); err != nil {
		pipelineErr(&c.Controller, 404, 404, "单位未找到")
		return
	}
	// 系统默认单位只读：不可编辑
	if row.IsDefault == 1 {
		pipelineErr(&c.Controller, 400, 400, "系统默认单位不可编辑")
		return
	}
	status := p.Status
	if status != 0 && status != 1 {
		status = row.Status
	}
	// 名称重复校验：与他人在用的单位冲突直接拒绝；命中的是历史软删除记录则彻底清理后继续
	var dup models.TenantCrmUnit
	if err := models.Orm.QueryTable(new(models.TenantCrmUnit)).
		Filter("tenant_id", tenantID).Filter("name", name).Exclude("id", id).One(&dup); err == nil {
		if dup.DeleteTime == nil {
			pipelineErr(&c.Controller, 400, 400, "单位名称已存在")
			return
		}
		_, _ = models.Orm.QueryTable(new(models.TenantCrmUnit)).Filter("id", dup.ID).Delete()
	}

	now := time.Now()
	_, err = models.Orm.QueryTable(new(models.TenantCrmUnit)).
		Filter("id", id).Filter("tenant_id", tenantID).
		Update(orm.Params{
			"name":        name,
			"code":        strings.TrimSpace(p.Code),
			"sort":        p.Sort,
			"status":      status,
			"remark":      strings.TrimSpace(p.Remark),
			"update_time": now,
		})
	if err != nil {
		if strings.Contains(err.Error(), "uk_tenant_name") {
			pipelineErr(&c.Controller, 400, 400, "单位名称已存在")
			return
		}
		pipelineErr(&c.Controller, 500, 500, "更新失败: "+err.Error())
		return
	}
	pipelineOk(&c.Controller, map[string]interface{}{"id": id})
}

// Delete DELETE /backend/crm/unit/:id
func (c *BackendCrmUnitController) Delete() {
	claims, err := pipelineClaims(&c.Controller)
	if err != nil {
		pipelineErr(&c.Controller, 401, 401, err.Error())
		return
	}
	id, _ := strconv.ParseUint(c.Ctx.Input.Param(":id"), 10, 64)
	if id == 0 {
		pipelineErr(&c.Controller, 400, 400, "无效的ID")
		return
	}
	tenantID := pipelineTenantID(claims)
	var row models.TenantCrmUnit
	if err := models.Orm.QueryTable(new(models.TenantCrmUnit)).
		Filter("id", id).Filter("tenant_id", tenantID).
		Filter("delete_time__isnull", true).One(&row); err != nil {
		pipelineErr(&c.Controller, 404, 404, "单位未找到")
		return
	}
	// 系统默认单位只读：不可删除
	if row.IsDefault == 1 {
		pipelineErr(&c.Controller, 400, 400, "系统默认单位不可删除")
		return
	}
	now := time.Now()
	_, err = models.Orm.QueryTable(new(models.TenantCrmUnit)).
		Filter("id", id).Filter("tenant_id", tenantID).
		Update(orm.Params{"delete_time": now, "update_time": now})
	if err != nil {
		pipelineErr(&c.Controller, 500, 500, "删除失败: "+err.Error())
		return
	}
	pipelineOk(&c.Controller, nil)
}

// InitDefault POST /backend/crm/unit/init-default —— 补齐缺失的系统默认单位
func (c *BackendCrmUnitController) InitDefault() {
	claims, err := pipelineClaims(&c.Controller)
	if err != nil {
		pipelineErr(&c.Controller, 401, 401, err.Error())
		return
	}
	added := crmInitDefaultUnits(pipelineTenantID(claims))
	pipelineOk(&c.Controller, map[string]interface{}{"added": added})
}