package handler

import (
	"errors"
	"kra/internal/service"
	"net/http"
	"net/url"
	"strings"

	"github.com/gin-gonic/gin"
	"github.com/google/uuid"
)

type Export struct {
	service *service.ExportService
}

func NewExport(service *service.ExportService) *Export {
	return &Export{service: service}
}

func exportParams(values url.Values) (map[string]string, error) {
	out := map[string]string{}
	nested, err := url.ParseQuery(values.Get("params"))
	if err != nil {
		return nil, err
	}
	for key, items := range nested {
		if len(items) > 0 {
			out[key] = items[0]
		}
	}
	return out, nil
}

func exportIssueParams(values url.Values, blank bool) (map[string]string, error) {
	params, err := exportParams(values)
	if err != nil && blank {
		return map[string]string{}, nil
	}
	return params, err
}

func (h *Export) Create(c *gin.Context) {
	var req service.ExportTemplateRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		Fail(c, err.Error())
		return
	}
	if req.Name == "" {
		Fail(c, "Name值不能为空")
		return
	}
	if err := h.service.CreateRequest(c.Request.Context(), &req); err != nil {
		Fail(c, "创建失败")
		return
	}
	Write(c, CodeSuccess, gin.H{}, "创建成功")
}
func (h *Export) Update(c *gin.Context) {
	var req service.ExportTemplateRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		Fail(c, err.Error())
		return
	}
	if req.Name == "" {
		Fail(c, "Name值不能为空")
		return
	}
	if err := h.service.UpdateRequest(c.Request.Context(), &req); err != nil {
		Fail(c, "更新失败")
		return
	}
	Write(c, CodeSuccess, gin.H{}, "更新成功")
}
func (h *Export) Delete(c *gin.Context) {
	var req service.IDRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		Fail(c, err.Error())
		return
	}
	// Deleting an empty model is rejected by GORM's global-update guard in the
	// reference endpoint. Preserve the same externally visible failure.
	if req.ID == 0 {
		Fail(c, "删除失败")
		return
	}
	if err := h.service.Delete(c.Request.Context(), []uint{req.ID}); err != nil {
		Fail(c, "删除失败")
		return
	}
	Write(c, CodeSuccess, gin.H{}, "删除成功")
}
func (h *Export) DeleteMany(c *gin.Context) {
	var req service.IDsRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		Fail(c, err.Error())
		return
	}
	if err := h.service.Delete(c.Request.Context(), req.IDs); err != nil {
		Fail(c, "批量删除失败")
		return
	}
	Write(c, CodeSuccess, gin.H{}, "批量删除成功")
}
func (h *Export) Find(c *gin.Context) {
	var req service.ExportTemplateRequest
	if err := c.ShouldBindQuery(&req); err != nil {
		Fail(c, err.Error())
		return
	}
	item, err := h.service.Template(c.Request.Context(), req.ID, "")
	if err != nil {
		Fail(c, "查询失败")
		return
	}
	OKWithData(c, gin.H{"resysExportTemplate": item})
}
func (h *Export) List(c *gin.Context) {
	p, size, err := page(c)
	if err != nil {
		Fail(c, err.Error())
		return
	}
	start, startErr := parseTime(c.Query("startCreatedAt"))
	end, endErr := parseTime(c.Query("endCreatedAt"))
	if startErr != nil || endErr != nil {
		Fail(c, "参数错误")
		return
	}
	items, total, err := h.service.TemplatesFilter(c.Request.Context(), p, size, c.Query("name"), c.Query("tableName"), c.Query("templateID"), start, end)
	if err != nil {
		Fail(c, "获取失败")
		return
	}
	Write(c, CodeSuccess, PageResult{List: items, Total: total, Page: p, PageSize: size}, "获取成功")
}
func (h *Export) Preview(c *gin.Context) {
	templateID := c.Query("templateID")
	if templateID == "" {
		Fail(c, "模板ID不能为空")
		return
	}
	params, _ := exportParams(c.Request.URL.Query())
	sql, err := h.service.Preview(c.Request.Context(), templateID, params)
	if err != nil {
		Fail(c, "获取失败")
		return
	}
	OKWithData(c, gin.H{"sql": sql})
}

func (h *Export) Issue(blank bool) gin.HandlerFunc {
	return func(c *gin.Context) {
		templateID := c.Query("templateID")
		if templateID == "" {
			Fail(c, "模板ID不能为空")
			return
		}
		params, err := exportIssueParams(c.Request.URL.Query(), blank)
		if err != nil {
			Fail(c, "解析 params 参数失败")
			return
		}
		token, err := h.service.IssueToken(c.Request.Context(), templateID, params, blank)
		if err != nil {
			Fail(c, "导出令牌创建失败")
			return
		}
		path := "/sysExportTemplate/exportExcelByToken?token=" + token
		if blank {
			path = "/sysExportTemplate/exportTemplateByToken?token=" + token
		}
		OKWithData(c, path)
	}
}

func (h *Export) Import(c *gin.Context) {
	templateID := c.Query("templateID")
	if templateID == "" {
		Fail(c, "模板ID不能为空")
		return
	}
	file, err := c.FormFile("file")
	if err != nil {
		Fail(c, "文件获取失败")
		return
	}
	opened, err := file.Open()
	if err != nil {
		Fail(c, "读取文件失败")
		return
	}
	defer opened.Close()
	if err = h.service.Import(c.Request.Context(), templateID, opened); err != nil {
		Fail(c, err.Error())
		return
	}
	Write(c, CodeSuccess, gin.H{}, "导入成功")
}

func (h *Export) Download(expectBlank bool) gin.HandlerFunc {
	return func(c *gin.Context) {
		token := c.Query("token")
		if token == "" {
			Fail(c, "导出token不能为空")
			return
		}
		value, err := h.service.ConsumeToken(c.Request.Context(), token, expectBlank)
		if err != nil {
			switch {
			case errors.Is(err, service.ErrExportTokenMalformed):
				Fail(c, "解析导出参数失败")
			case errors.Is(err, service.ErrExportTokenType):
				Fail(c, "token类型错误")
			default:
				Fail(c, "导出token无效或已过期")
			}
			return
		}
		var data []byte
		var name string
		if expectBlank {
			data, name, err = h.service.ExportBlankTemplate(c.Request.Context(), value.TemplateID)
		} else {
			data, name, err = h.service.Export(c.Request.Context(), value.TemplateID, value.Params)
		}
		if err != nil {
			Fail(c, "获取失败")
			return
		}
		if expectBlank {
			name = strings.TrimSuffix(name, "_template.xlsx") + "模板.xlsx"
		} else {
			name = strings.TrimSuffix(name, ".xlsx") + strings.ReplaceAll(uuid.NewString(), "-", "")[:6] + ".xlsx"
		}
		c.Header("Content-Disposition", "attachment; filename="+name)
		c.Header("success", "true")
		c.Data(http.StatusOK, "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet", data)
	}
}