package photos

import (
	"errors"
	"io"
	"net/http"
	"strconv"
	"time"

	"github.com/gin-gonic/gin"

	"galo/internal/auth"
	"galo/internal/httpx"
)

const maxUploadSize = 100 << 20

type Handler struct {
	svc *Service
}

func NewHandler(svc *Service) *Handler { return &Handler{svc: svc} }

func (h *Handler) List(c *gin.Context) {
	limit, _ := strconv.Atoi(c.DefaultQuery("limit", "50"))
	var since *time.Time
	if raw := c.Query("since"); raw != "" {
		if t, err := time.Parse(time.RFC3339, raw); err == nil {
			since = &t
		} else if ms, err := strconv.ParseInt(raw, 10, 64); err == nil {
			t := time.UnixMilli(ms)
			since = &t
		}
	}
	list, next, err := h.svc.List(c.Request.Context(), c.Param("id"), auth.UserID(c), c.Query("cursor"), since, limit)
	if err != nil {
		httpx.RespondError(c, err)
		return
	}
	c.JSON(http.StatusOK, gin.H{"photos": list, "next_cursor": next})
}

func (h *Handler) Upload(c *gin.Context) {
	c.Request.Body = http.MaxBytesReader(c.Writer, c.Request.Body, maxUploadSize)
	form, err := c.MultipartForm()
	if err != nil {
		var maxErr *http.MaxBytesError
		if errors.As(err, &maxErr) {
			httpx.RespondError(c, httpx.NewError(http.StatusRequestEntityTooLarge, "file_too_large", "files exceed the maximum upload size (100 MB)"))
			return
		}
		httpx.RespondError(c, httpx.BadRequest("invalid_request", "invalid multipart form"))
		return
	}
	files := form.File["files"]
	if len(files) == 0 {
		files = form.File["file"]
	}
	if len(files) == 0 {
		httpx.RespondError(c, httpx.BadRequest("no_files", "no files provided"))
		return
	}

	created := make([]any, 0, len(files))
	for _, fh := range files {
		f, err := fh.Open()
		if err != nil {
			httpx.RespondError(c, err)
			return
		}
		data, err := io.ReadAll(io.LimitReader(f, maxUploadSize))
		f.Close()
		if err != nil {
			httpx.RespondError(c, err)
			return
		}
		p, err := h.svc.Upload(c.Request.Context(), UploadInput{
			AlbumID:  c.Param("id"),
			UserID:   auth.UserID(c),
			Filename: fh.Filename,
			MimeType: fh.Header.Get("Content-Type"),
			Data:     data,
		})
		if err != nil {
			httpx.RespondError(c, err)
			return
		}
		created = append(created, p)
	}
	c.JSON(http.StatusCreated, gin.H{"photos": created})
}

func (h *Handler) Get(c *gin.Context) {
	p, err := h.svc.Get(c.Request.Context(), c.Param("id"), auth.UserID(c))
	if err != nil {
		httpx.RespondError(c, err)
		return
	}
	c.JSON(http.StatusOK, gin.H{"photo": p})
}

type renameRequest struct {
	OriginalFilename string `json:"original_filename" binding:"required"`
}

func (h *Handler) Rename(c *gin.Context) {
	var req renameRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		httpx.RespondError(c, httpx.BadRequest("invalid_request", "original_filename is required"))
		return
	}
	p, err := h.svc.Rename(c.Request.Context(), c.Param("id"), auth.UserID(c), req.OriginalFilename)
	if err != nil {
		httpx.RespondError(c, err)
		return
	}
	c.JSON(http.StatusOK, gin.H{"photo": p})
}

func (h *Handler) Download(c *gin.Context) {
	url, err := h.svc.Download(c.Request.Context(), c.Param("id"), auth.UserID(c))
	if err != nil {
		httpx.RespondError(c, err)
		return
	}
	c.JSON(http.StatusOK, gin.H{"url": url})
}

func (h *Handler) Delete(c *gin.Context) {
	if err := h.svc.Delete(c.Request.Context(), c.Param("id"), auth.UserID(c)); err != nil {
		httpx.RespondError(c, err)
		return
	}
	c.Status(http.StatusNoContent)
}

func (h *Handler) PermanentDelete(c *gin.Context) {
	if err := h.svc.PermanentDelete(c.Request.Context(), c.Param("id"), auth.UserID(c)); err != nil {
		httpx.RespondError(c, err)
		return
	}
	c.Status(http.StatusNoContent)
}

func (h *Handler) Restore(c *gin.Context) {
	var req struct {
		AlbumID string `json:"album_id"`
	}
	_ = c.ShouldBindJSON(&req)
	p, err := h.svc.Restore(c.Request.Context(), c.Param("id"), auth.UserID(c), req.AlbumID)
	if err != nil {
		httpx.RespondError(c, err)
		return
	}
	c.JSON(http.StatusOK, gin.H{"photo": p})
}

func (h *Handler) Trash(c *gin.Context) {
	list, err := h.svc.Trash(c.Request.Context(), auth.UserID(c))
	if err != nil {
		httpx.RespondError(c, err)
		return
	}
	c.JSON(http.StatusOK, gin.H{"photos": list})
}

func (h *Handler) TrashCount(c *gin.Context) {
	n, err := h.svc.TrashCount(c.Request.Context(), auth.UserID(c))
	if err != nil {
		httpx.RespondError(c, err)
		return
	}
	c.JSON(http.StatusOK, gin.H{"count": n})
}

func (h *Handler) Tags(c *gin.Context) {
	tags, err := h.svc.Tags(c.Request.Context(), auth.UserID(c), c.Query("q"))
	if err != nil {
		httpx.RespondError(c, err)
		return
	}
	c.JSON(http.StatusOK, gin.H{"tags": tags})
}

func (h *Handler) AddTag(c *gin.Context) {
	var req struct {
		Name string `json:"name"`
	}
	if err := c.ShouldBindJSON(&req); err != nil || req.Name == "" {
		httpx.RespondError(c, httpx.BadRequest("invalid_request", "name is required"))
		return
	}
	p, err := h.svc.AddTag(c.Request.Context(), c.Param("id"), auth.UserID(c), req.Name)
	if err != nil {
		httpx.RespondError(c, err)
		return
	}
	c.JSON(http.StatusOK, gin.H{"photo": p})
}

func (h *Handler) RemoveTag(c *gin.Context) {
	p, err := h.svc.RemoveTag(c.Request.Context(), c.Param("id"), auth.UserID(c), c.Param("tag_id"))
	if err != nil {
		httpx.RespondError(c, err)
		return
	}
	c.JSON(http.StatusOK, gin.H{"photo": p})
}

type batchRequest struct {
	IDs     []string `json:"ids" binding:"required"`
	AlbumID string   `json:"album_id"`
}

func (h *Handler) DeleteBatch(c *gin.Context) {
	var req batchRequest
	if err := c.ShouldBindJSON(&req); err != nil || len(req.IDs) == 0 {
		httpx.RespondError(c, httpx.BadRequest("invalid_request", "ids are required"))
		return
	}
	n, err := h.svc.DeleteBatch(c.Request.Context(), req.IDs, auth.UserID(c))
	if err != nil {
		httpx.RespondError(c, err)
		return
	}
	c.JSON(http.StatusOK, gin.H{"deleted": n})
}

func (h *Handler) MoveBatch(c *gin.Context) {
	var req batchRequest
	if err := c.ShouldBindJSON(&req); err != nil || len(req.IDs) == 0 || req.AlbumID == "" {
		httpx.RespondError(c, httpx.BadRequest("invalid_request", "ids and album_id are required"))
		return
	}
	n, err := h.svc.MoveBatch(c.Request.Context(), req.IDs, auth.UserID(c), req.AlbumID)
	if err != nil {
		httpx.RespondError(c, err)
		return
	}
	c.JSON(http.StatusOK, gin.H{"moved": n})
}

func (h *Handler) CopyBatch(c *gin.Context) {
	var req batchRequest
	if err := c.ShouldBindJSON(&req); err != nil || len(req.IDs) == 0 || req.AlbumID == "" {
		httpx.RespondError(c, httpx.BadRequest("invalid_request", "ids and album_id are required"))
		return
	}
	created, err := h.svc.CopyBatch(c.Request.Context(), req.IDs, auth.UserID(c), req.AlbumID)
	if err != nil {
		httpx.RespondError(c, err)
		return
	}
	c.JSON(http.StatusOK, gin.H{"photos": created})
}