package handler

import (
	"errors"
	"io"
	"net/http"
	"path/filepath"
	"strconv"
	"strings"

	"github.com/Tencent/WeKnora/internal/application/service"
	apperrors "github.com/Tencent/WeKnora/internal/errors"
	"github.com/Tencent/WeKnora/internal/logger"
	"github.com/Tencent/WeKnora/internal/types"
	"github.com/gin-gonic/gin"
)

type DigitalHumanHandler struct{ service *service.DigitalHumanService }

func NewDigitalHumanHandler(svc *service.DigitalHumanService) *DigitalHumanHandler {
	return &DigitalHumanHandler{service: svc}
}

func digitalHumanHTTPError(c *gin.Context, err error) {
	var inputError *types.DigitalHumanInputError
	switch {
	case errors.Is(err, types.ErrDigitalHumanNotFound):
		c.Error(apperrors.NewNotFoundError(err.Error()))
	case errors.Is(err, types.ErrDigitalHumanIdentity):
		c.Error(apperrors.NewUnauthorizedError(err.Error()))
	case errors.Is(err, types.ErrDigitalHumanConflict):
		c.Error(apperrors.NewConflictError(err.Error()))
	case errors.As(err, &inputError):
		c.Error(apperrors.NewBadRequestError(inputError.Error()))
	default:
		logger.ErrorWithFields(c.Request.Context(), err, map[string]interface{}{"feature": "digital_human"})
		c.Error(apperrors.NewInternalServerError("数字人操作失败，请稍后重试"))
	}
}

func (h *DigitalHumanHandler) List(c *gin.Context) {
	offset, _ := strconv.Atoi(c.Query("offset"))
	limit, _ := strconv.Atoi(c.Query("limit"))
	data, err := h.service.List(c.Request.Context(), offset, limit)
	if err != nil {
		digitalHumanHTTPError(c, err)
		return
	}
	c.JSON(http.StatusOK, gin.H{"success": true, "data": data})
}

func (h *DigitalHumanHandler) Get(c *gin.Context) {
	data, err := h.service.Get(c.Request.Context(), c.Param("id"))
	if err != nil {
		digitalHumanHTTPError(c, err)
		return
	}
	c.JSON(http.StatusOK, gin.H{"success": true, "data": data})
}

func (h *DigitalHumanHandler) Create(c *gin.Context) {
	c.Request.Body = http.MaxBytesReader(c.Writer, c.Request.Body, 2<<20)
	var input service.DigitalHumanInput
	if err := c.ShouldBindJSON(&input); err != nil {
		c.Error(apperrors.NewBadRequestError("请填写有效的数字人资料"))
		return
	}
	data, err := h.service.Create(c.Request.Context(), input)
	if err != nil {
		digitalHumanHTTPError(c, err)
		return
	}
	c.JSON(http.StatusCreated, gin.H{"success": true, "data": data})
}

func (h *DigitalHumanHandler) Update(c *gin.Context) {
	c.Request.Body = http.MaxBytesReader(c.Writer, c.Request.Body, 2<<20)
	var input service.DigitalHumanInput
	if err := c.ShouldBindJSON(&input); err != nil {
		c.Error(apperrors.NewBadRequestError("请填写有效的数字人资料"))
		return
	}
	data, err := h.service.Update(c.Request.Context(), c.Param("id"), input)
	if err != nil {
		digitalHumanHTTPError(c, err)
		return
	}
	c.JSON(http.StatusOK, gin.H{"success": true, "data": data})
}

func (h *DigitalHumanHandler) Delete(c *gin.Context) {
	if err := h.service.Delete(c.Request.Context(), c.Param("id")); err != nil {
		digitalHumanHTTPError(c, err)
		return
	}
	c.JSON(http.StatusOK, gin.H{"success": true})
}

func (h *DigitalHumanHandler) Review(c *gin.Context) {
	c.Request.Body = http.MaxBytesReader(c.Writer, c.Request.Body, 32<<10)
	var input struct {
		Version int    `json:"version"`
		Approve *bool  `json:"approve"`
		Note    string `json:"note"`
	}
	if err := c.ShouldBindJSON(&input); err != nil || input.Approve == nil || input.Version < 1 {
		c.Error(apperrors.NewBadRequestError("请选择审核版本和通过或退回"))
		return
	}
	data, err := h.service.Review(c.Request.Context(), c.Param("id"), input.Version, *input.Approve, input.Note)
	if err != nil {
		digitalHumanHTTPError(c, err)
		return
	}
	c.JSON(http.StatusOK, gin.H{"success": true, "data": data})
}

func (h *DigitalHumanHandler) Bind(c *gin.Context) {
	c.Request.Body = http.MaxBytesReader(c.Writer, c.Request.Body, 4096)
	var input struct {
		AgentID string `json:"agent_id"`
	}
	if err := c.ShouldBindJSON(&input); err != nil || input.AgentID == "" {
		c.Error(apperrors.NewBadRequestError("请选择 Agent"))
		return
	}
	if err := h.service.Bind(c.Request.Context(), c.Param("id"), input.AgentID); err != nil {
		digitalHumanHTTPError(c, err)
		return
	}
	c.JSON(http.StatusOK, gin.H{"success": true})
}

func (h *DigitalHumanHandler) Unbind(c *gin.Context) {
	if err := h.service.Unbind(c.Request.Context(), c.Param("id"), c.Param("agent_id")); err != nil {
		digitalHumanHTTPError(c, err)
		return
	}
	c.JSON(http.StatusOK, gin.H{"success": true})
}

func (h *DigitalHumanHandler) Distill(c *gin.Context) {
	var input service.DigitalHumanDistillInput
	if strings.HasPrefix(c.ContentType(), "multipart/form-data") {
		// Authorize before accepting or parsing potentially large private documents.
		if err := h.service.CheckOwner(c.Request.Context(), c.Param("id")); err != nil {
			digitalHumanHTTPError(c, err)
			return
		}
		c.Request.Body = http.MaxBytesReader(c.Writer, c.Request.Body, service.DigitalHumanUploadLimit)
		if err := c.Request.ParseMultipartForm(4 << 20); err != nil {
			c.Error(apperrors.NewBadRequestError("上传材料总大小不能超过50MB"))
			return
		}
		defer c.Request.MultipartForm.RemoveAll()
		if len(c.Request.MultipartForm.File["files"]) > service.DigitalHumanFileCountLimit {
			c.Error(apperrors.NewBadRequestError("每次最多上传99份材料"))
			return
		}
		input.Advice, input.ModelID = c.PostForm("advice"), c.PostForm("model_id")
		input.Revision, _ = strconv.ParseInt(c.PostForm("revision"), 10, 64)
		if text := strings.TrimSpace(c.PostForm("text")); text != "" {
			input.Sources = append(input.Sources, types.DigitalHumanSource{Name: "补充原稿", Text: text})
		}
		for _, header := range c.Request.MultipartForm.File["files"] {
			if !service.DigitalHumanUploadSupported(header.Filename) {
				c.Error(apperrors.NewBadRequestError("支持 Word、PDF、PPT、MD、TXT、SRT、VTT、RTF、ODT、CSV、JSON 和 HTML 材料"))
				return
			}
			file, err := header.Open()
			if err != nil {
				c.Error(apperrors.NewBadRequestError("无法读取上传材料"))
				return
			}
			data, readErr := io.ReadAll(io.LimitReader(file, service.DigitalHumanFileLimit+1))
			file.Close()
			if readErr != nil || len(data) > service.DigitalHumanFileLimit || len(data) == 0 {
				c.Error(apperrors.NewBadRequestError("单份材料须有内容且不能超过20MB"))
				return
			}
			input.Files = append(input.Files, service.DigitalHumanUpload{Name: filepath.Base(header.Filename), Data: data})
		}
	} else {
		c.Request.Body = http.MaxBytesReader(c.Writer, c.Request.Body, 2<<20)
		if err := c.ShouldBindJSON(&input); err != nil {
			c.Error(apperrors.NewBadRequestError("请提供有效的蒸馏原稿和建议"))
			return
		}
	}
	job, err := h.service.Distill(c.Request.Context(), c.Param("id"), input)
	if err != nil {
		digitalHumanHTTPError(c, err)
		return
	}
	c.JSON(http.StatusAccepted, gin.H{"success": true, "data": job})
}

func (h *DigitalHumanHandler) Job(c *gin.Context) {
	job, err := h.service.Job(c.Request.Context(), c.Param("id"), c.Param("job_id"))
	if err != nil {
		digitalHumanHTTPError(c, err)
		return
	}
	c.JSON(http.StatusOK, gin.H{"success": true, "data": job})
}