package handlers

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

	"gitea.loveuer.com/loveuer/cluster/internal/registry/storage"

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

// StartBlobUpload 开始 blob 上传
func StartBlobUpload(store storage.Storage) gin.HandlerFunc {
	return func(c *gin.Context) {
		repo := c.GetString("repo_name")
		if repo == "" {
			repo = strings.TrimPrefix(c.Param("name"), "/")
		}

		uuid, err := store.StartBlobUpload(repo)
		if err != nil {
			c.JSON(http.StatusInternalServerError, gin.H{
				"errors": []gin.H{
					{
						"code":    "INTERNAL_ERROR",
						"message": err.Error(),
					},
				},
			})
			return
		}

		// 返回上传 URL
		location := c.Request.URL.Path + "/" + uuid
		c.Header("Location", location)
		c.Header("Docker-Upload-UUID", uuid)
		c.Header("Range", "0-0")
		c.Status(http.StatusAccepted)
	}
}

// PatchBlobUpload 上传 blob 数据块
func PatchBlobUpload(store storage.Storage) gin.HandlerFunc {
	return func(c *gin.Context) {
		uuid := c.Param("uuid")

		// 获取 Range header
		rangeHeader := c.GetHeader("Content-Range")
		if rangeHeader == "" {
			c.JSON(http.StatusBadRequest, gin.H{
				"errors": []gin.H{
					{
						"code":    "BAD_REQUEST",
						"message": "Content-Range header required",
					},
				},
			})
			return
		}

		// 读取数据
		data := c.Request.Body
		if err := store.PutBlobUploadChunk(uuid, data); err != nil {
			c.JSON(http.StatusInternalServerError, gin.H{
				"errors": []gin.H{
					{
						"code":    "INTERNAL_ERROR",
						"message": err.Error(),
					},
				},
			})
			return
		}

		// 获取当前上传大小
		size, err := store.GetBlobUpload(uuid)
		if err != nil {
			c.JSON(http.StatusNotFound, gin.H{
				"errors": []gin.H{
					{
						"code":    "UPLOAD_UNKNOWN",
						"message": err.Error(),
					},
				},
			})
			return
		}

		location := c.Request.URL.Path
		c.Header("Location", location)
		c.Header("Docker-Upload-UUID", uuid)
		c.Header("Range", "0-"+strconv.FormatInt(size-1, 10))
		c.Status(http.StatusNoContent)
	}
}

// PutBlobUpload 完成 blob 上传
func PutBlobUpload(store storage.Storage) gin.HandlerFunc {
	return func(c *gin.Context) {
		repo := c.GetString("repo_name")
		if repo == "" {
			repo = strings.TrimPrefix(c.Param("name"), "/")
		}
		uuid := c.Param("uuid")

		// 获取 digest
		digest := c.Query("digest")
		if digest == "" {
			c.JSON(http.StatusBadRequest, gin.H{
				"errors": []gin.H{
					{
						"code":    "BAD_REQUEST",
						"message": "digest query parameter required",
					},
				},
			})
			return
		}

		// 如果有请求体，先追加数据
		if c.Request.ContentLength > 0 {
			if err := store.PutBlobUploadChunk(uuid, c.Request.Body); err != nil {
				c.JSON(http.StatusInternalServerError, gin.H{
					"errors": []gin.H{
						{
							"code":    "INTERNAL_ERROR",
							"message": err.Error(),
						},
					},
				})
				return
			}
		}

		// 完成上传
		if err := store.CompleteBlobUpload(repo, uuid, digest); err != nil {
			c.JSON(http.StatusBadRequest, gin.H{
				"errors": []gin.H{
					{
						"code":    "BAD_REQUEST",
						"message": err.Error(),
					},
				},
			})
			return
		}

		// 清理上传文件
		store.DeleteBlobUpload(uuid)

		// 返回 blob 位置
		// 从 /v2/{name}/blobs/uploads/{uuid} 转换为 /v2/{name}/blobs/{digest}
		pathParts := strings.Split(c.Request.URL.Path, "/")
		if len(pathParts) >= 4 {
			// 构建新的路径: /v2/{name}/blobs/{digest}
			location := "/v2/" + pathParts[2] + "/blobs/" + digest
			c.Header("Location", location)
		} else {
			c.Header("Location", c.Request.URL.Path)
		}
		c.Header("Content-Length", "0")
		c.Header("Docker-Content-Digest", digest)
		c.Status(http.StatusCreated)
	}
}

// GetBlobUpload 获取上传状态
func GetBlobUpload(store storage.Storage) gin.HandlerFunc {
	return func(c *gin.Context) {
		uuid := c.Param("uuid")

		size, err := store.GetBlobUpload(uuid)
		if err != nil {
			c.JSON(http.StatusNotFound, gin.H{
				"errors": []gin.H{
					{
						"code":    "UPLOAD_UNKNOWN",
						"message": err.Error(),
					},
				},
			})
			return
		}

		location := c.Request.URL.Path
		c.Header("Location", location)
		c.Header("Docker-Upload-UUID", uuid)
		c.Header("Range", "0-"+strconv.FormatInt(size-1, 10))
		c.Status(http.StatusNoContent)
	}
}