package transport

import (
	"io"
	"net/http"
	"strconv"
	"strings"

	"github.com/gin-gonic/gin"

	"github.com/geo-platform/tenant-api/internal/ops/app"
	"github.com/geo-platform/tenant-api/internal/shared/objectstorage"
	"github.com/geo-platform/tenant-api/internal/shared/response"
)

const (
	maxObjectStorageUploadBytes    = 500 * 1024 * 1024
	maxObjectStorageMultipartBytes = maxObjectStorageUploadBytes + 1*1024*1024
)

type moveObjectStorageObjectRequest struct {
	SourceKey      string `json:"source_key" binding:"required"`
	DestinationKey string `json:"destination_key" binding:"required"`
	Overwrite      bool   `json:"overwrite"`
	DeleteSource   *bool  `json:"delete_source"`
}

type createObjectStorageFolderRequest struct {
	Prefix string `json:"prefix" binding:"required"`
}

func listObjectStorageObjectsHandler(svc *app.ObjectStorageService) gin.HandlerFunc {
	return func(c *gin.Context) {
		size, _ := strconv.Atoi(c.DefaultQuery("size", "100"))
		result, err := svc.List(c.Request.Context(), app.ObjectStorageListInput{
			Prefix:            c.Query("prefix"),
			Keyword:           c.Query("keyword"),
			ContinuationToken: c.Query("continuation_token"),
			StartAfter:        c.Query("start_after"),
			Recursive:         c.Query("recursive") == "true",
			Size:              size,
		})
		if err != nil {
			response.Error(c, err)
			return
		}
		response.Success(c, result)
	}
}

func getObjectStorageUsageHandler(svc *app.ObjectStorageService) gin.HandlerFunc {
	return func(c *gin.Context) {
		result, err := svc.Usage(c.Request.Context())
		if err != nil {
			response.Error(c, err)
			return
		}
		response.Success(c, result)
	}
}

func getObjectStorageObjectHandler(svc *app.ObjectStorageService) gin.HandlerFunc {
	return func(c *gin.Context) {
		result, err := svc.Get(c.Request.Context(), c.Query("key"))
		if err != nil {
			response.Error(c, err)
			return
		}
		response.Success(c, result)
	}
}

func resolveObjectStorageObjectURLHandler(svc *app.ObjectStorageService) gin.HandlerFunc {
	return func(c *gin.Context) {
		urlValue, err := svc.ResolvePublicURL(c.Request.Context(), c.Query("key"))
		if err != nil {
			response.Error(c, err)
			return
		}
		response.Success(c, gin.H{"url": urlValue})
	}
}

func resolveObjectStorageObjectDownloadURLHandler(svc *app.ObjectStorageService) gin.HandlerFunc {
	return func(c *gin.Context) {
		urlValue, err := svc.ResolveDownloadURL(c.Request.Context(), c.Query("key"))
		if err != nil {
			response.Error(c, err)
			return
		}
		response.Success(c, gin.H{"url": urlValue})
	}
}

func downloadObjectStorageObjectHandler(svc *app.ObjectStorageService) gin.HandlerFunc {
	return func(c *gin.Context) {
		key := c.Query("key")
		content, info, err := svc.Download(c.Request.Context(), key)
		if err != nil {
			response.Error(c, err)
			return
		}
		c.Header("Cache-Control", "no-store")
		c.Header("Content-Disposition", objectStorageDownloadDisposition(key))
		c.Data(http.StatusOK, objectStorageDownloadContentType(info, content), content)
	}
}

func uploadObjectStorageObjectHandler(svc *app.ObjectStorageService) gin.HandlerFunc {
	return func(c *gin.Context) {
		if c.Request.ContentLength > maxObjectStorageMultipartBytes {
			response.Error(c, response.ErrBadRequest(40095, "object_storage_file_too_large", "单个对象不能超过 500MB"))
			return
		}
		c.Request.Body = http.MaxBytesReader(c.Writer, c.Request.Body, maxObjectStorageMultipartBytes)

		fileHeader, err := c.FormFile("file")
		if err != nil {
			if strings.Contains(err.Error(), "request body too large") {
				response.Error(c, response.ErrBadRequest(40095, "object_storage_file_too_large", "单个对象不能超过 500MB"))
				return
			}
			response.Error(c, response.ErrBadRequest(40094, "object_storage_file_required", "请选择要上传的文件"))
			return
		}
		file, err := fileHeader.Open()
		if err != nil {
			response.Error(c, response.ErrBadRequest(40094, "object_storage_file_open_failed", "文件读取失败"))
			return
		}
		defer file.Close()

		content, err := io.ReadAll(io.LimitReader(file, maxObjectStorageUploadBytes+1))
		if err != nil {
			response.Error(c, response.ErrBadRequest(40094, "object_storage_file_read_failed", "文件读取失败"))
			return
		}
		if len(content) > maxObjectStorageUploadBytes {
			response.Error(c, response.ErrBadRequest(40095, "object_storage_file_too_large", "单个对象不能超过 500MB"))
			return
		}
		result, err := svc.Upload(c.Request.Context(), actorFromGin(c), app.ObjectStorageUploadInput{
			ObjectKey:   c.PostForm("key"),
			FileName:    fileHeader.Filename,
			Content:     content,
			ContentType: c.PostForm("content_type"),
			Overwrite:   c.PostForm("overwrite") == "true",
		})
		if err != nil {
			response.Error(c, err)
			return
		}
		response.Success(c, result)
	}
}

func moveObjectStorageObjectHandler(svc *app.ObjectStorageService) gin.HandlerFunc {
	return func(c *gin.Context) {
		var body moveObjectStorageObjectRequest
		if err := c.ShouldBindJSON(&body); err != nil {
			response.Error(c, response.ErrBadRequest(40000, "invalid_payload", err.Error()))
			return
		}
		deleteSource := true
		if body.DeleteSource != nil {
			deleteSource = *body.DeleteSource
		}
		result, err := svc.Move(c.Request.Context(), actorFromGin(c), app.ObjectStorageMoveInput{
			SourceKey:      body.SourceKey,
			DestinationKey: body.DestinationKey,
			Overwrite:      body.Overwrite,
			DeleteSource:   deleteSource,
		})
		if err != nil {
			response.Error(c, err)
			return
		}
		response.Success(c, result)
	}
}

func deleteObjectStorageObjectHandler(svc *app.ObjectStorageService) gin.HandlerFunc {
	return func(c *gin.Context) {
		key := c.Query("key")
		if err := svc.Delete(c.Request.Context(), actorFromGin(c), key); err != nil {
			response.Error(c, err)
			return
		}
		response.Success(c, gin.H{"key": key})
	}
}

func createObjectStorageFolderHandler(svc *app.ObjectStorageService) gin.HandlerFunc {
	return func(c *gin.Context) {
		var body createObjectStorageFolderRequest
		if err := c.ShouldBindJSON(&body); err != nil {
			response.Error(c, response.ErrBadRequest(40000, "invalid_payload", err.Error()))
			return
		}
		result, err := svc.CreateFolder(c.Request.Context(), actorFromGin(c), app.ObjectStorageFolderCreateInput{
			Prefix: body.Prefix,
		})
		if err != nil {
			response.Error(c, err)
			return
		}
		response.Success(c, result)
	}
}

func deleteObjectStorageFolderHandler(svc *app.ObjectStorageService) gin.HandlerFunc {
	return func(c *gin.Context) {
		prefix := c.Query("prefix")
		result, err := svc.DeleteFolder(c.Request.Context(), actorFromGin(c), prefix)
		if err != nil {
			response.Error(c, err)
			return
		}
		response.Success(c, result)
	}
}

func objectStorageDownloadDisposition(key string) string {
	return objectstorage.DownloadContentDisposition(key)
}

func objectStorageDownloadContentType(info *objectstorage.ObjectInfo, content []byte) string {
	if info != nil && strings.TrimSpace(info.ContentType) != "" {
		return info.ContentType
	}
	if len(content) > 0 {
		return http.DetectContentType(content)
	}
	return "application/octet-stream"
}