package main

import (
	"context"
	"encoding/json"
	"log/slog"
	"net/http"
	"net/url"
	"os"
	"path/filepath"

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

type photosMoveBody struct {
	UIDs         []string `json:"uids"`
	TargetFolder string   `json:"targetFolder"`
	Mode         string   `json:"mode"`      // "move" or "copy"
	Subfolder    string   `json:"subfolder"` // optional, sanitized to a single segment
}

// handlePhotosMove moves/copies an arbitrary list of photos (by UID) into a
// folder under originals/. Mirrors handleHeapConvert but resolves the photos
// from a UID list instead of an album query, then shares movePhotoFiles for
// the on-disk work + reindex. Backs the grid's "Move to folder" action.
func handlePhotosMove(cfg *Config, pp *ppClient) gin.HandlerFunc {
	return func(c *gin.Context) {
		token := ctxToken(c)

		var body photosMoveBody
		if err := c.ShouldBindJSON(&body); err != nil {
			c.JSON(http.StatusBadRequest, gin.H{"error": "invalid json"})
			return
		}
		if len(body.UIDs) == 0 {
			c.JSON(http.StatusBadRequest, gin.H{"error": "no uids"})
			return
		}
		mode := body.Mode
		if mode != "copy" {
			mode = "move"
		}

		var subfolder string
		if body.Subfolder != "" {
			s, ok := sanitizeFilename(body.Subfolder)
			if !ok {
				c.JSON(http.StatusBadRequest, gin.H{"error": "invalid subfolder name"})
				return
			}
			subfolder = s
		}

		targetAbs, err := resolveMoveTarget(cfg, body.TargetFolder)
		if err != nil {
			c.JSON(http.StatusBadRequest, gin.H{"error": "invalid targetFolder"})
			return
		}
		if !requireUserScope(c, cfg, targetAbs, false) {
			return
		}

		// Resolve each photo's FULL file list via the single-photo endpoint
		// rather than the /photos search (see resolvePhotosFull) — the search
		// drops a photo's video file from its trimmed Files array and filters
		// videos out by quality/review, so the .mov never gets listed to move.
		photos, resolveErrs, err := resolvePhotosFull(c.Request.Context(), pp, token, body.UIDs)
		if err != nil {
			c.JSON(http.StatusBadGateway, gin.H{"error": err.Error()})
			return
		}

		moved, copied, errs, err := movePhotoFiles(cfg, pp, token, photos, targetAbs, subfolder, mode, userScopeRoot(c, cfg))
		if err != nil {
			c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
			return
		}
		// Surface UIDs PhotoPrism couldn't resolve alongside any per-file
		// errors so the client's "N skipped" summary stays accurate.
		errs = append(resolveErrs, errs...)

		slog.Info("photos.move",
			"requested", len(body.UIDs),
			"mode", mode,
			"moved", moved,
			"copied", copied,
			"errors", len(errs),
		)
		c.JSON(http.StatusOK, gin.H{
			"moved":  moved,
			"copied": copied,
			"errors": errs,
		})
	}
}

// resolvePhotosFull fetches each photo's complete file list via the
// single-photo endpoint (GET /photos/:uid). Use this instead of the /photos
// search whenever you need every file of a photo: the search — even with
// merged=true — can return a trimmed Files array that omits the photo's video
// file, and it applies PhotoPrism's default quality/review/archive filters.
// Both silently drop videos (which PhotoPrism routinely files under review)
// from a move. The per-UID lookup returns every file and ignores those
// filters. UIDs PhotoPrism can't resolve are returned in `errs` so the batch
// continues; a transport-level failure aborts with a fatal error. Mirrors
// handleRename's single-photo resolution.
func resolvePhotosFull(ctx context.Context, pp *ppClient, token string, uids []string) (photos []heapPhoto, errs []heapErr, err error) {
	photos = make([]heapPhoto, 0, len(uids))
	for _, uid := range uids {
		resp, e := pp.call(ctx, http.MethodGet, "/api/v1/photos/"+url.PathEscape(uid), token, nil)
		if e != nil {
			return nil, nil, e
		}
		if !resp.OK {
			errs = append(errs, heapErr{UID: uid, Reason: "photo not found"})
			continue
		}
		var p heapPhoto
		if e := json.Unmarshal(resp.Body, &p); e != nil {
			return nil, nil, e
		}
		photos = append(photos, p)
	}
	return photos, errs, nil
}

type folderMoveBody struct {
	// Originals-relative destination parent. ""/"/"/"." mean the root.
	TargetParent string `json:"targetParent"`
}

// handleFolderMove reparents a folder: moves the directory (and everything in
// it) under a different parent, keeping its own name. Mirrors
// handleFolderRename but the destination is a parent folder rather than a new
// name. A whole-tree os.Rename preserves subfolder structure.
func handleFolderMove(cfg *Config, pp *ppClient) gin.HandlerFunc {
	return func(c *gin.Context) {
		token := ctxToken(c)
		rel, ok := pathParam(c, "rel")
		if !ok {
			c.JSON(http.StatusBadRequest, gin.H{"error": "invalid path"})
			return
		}
		var body folderMoveBody
		if err := c.ShouldBindJSON(&body); err != nil {
			c.JSON(http.StatusBadRequest, gin.H{"error": "invalid json"})
			return
		}
		oldAbs, err := resolveUnderRoot(cfg.OriginalsRoot, rel, true)
		if err != nil {
			c.JSON(http.StatusBadRequest, gin.H{"error": "invalid path"})
			return
		}
		if !requireUserScope(c, cfg, oldAbs, true) {
			return
		}
		st, err := os.Stat(oldAbs)
		if err != nil || !st.IsDir() {
			c.JSON(http.StatusBadRequest, gin.H{"error": "not a directory"})
			return
		}
		targetParentAbs, err := resolveMoveTarget(cfg, body.TargetParent)
		if err != nil {
			c.JSON(http.StatusBadRequest, gin.H{"error": "invalid targetParent"})
			return
		}
		if !requireUserScope(c, cfg, targetParentAbs, false) {
			return
		}
		// Can't move a folder into itself or one of its own descendants.
		if sameOrUnder(targetParentAbs, oldAbs) {
			c.JSON(http.StatusBadRequest, gin.H{"error": "cannot move a folder into itself"})
			return
		}
		newAbs := filepath.Join(targetParentAbs, filepath.Base(oldAbs))
		if newAbs == oldAbs {
			c.JSON(http.StatusBadRequest, gin.H{"error": "already in that folder"})
			return
		}
		if !sameOrUnder(newAbs, cfg.OriginalsRoot) {
			c.JSON(http.StatusBadRequest, gin.H{"error": "target escapes root"})
			return
		}
		if _, err := os.Stat(newAbs); err == nil {
			c.JSON(http.StatusConflict, gin.H{"error": "target already exists"})
			return
		}
		if err := os.Rename(oldAbs, newAbs); err != nil {
			c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
			return
		}
		oldRel, _ := filepath.Rel(cfg.OriginalsRoot, oldAbs)
		newRel, _ := filepath.Rel(cfg.OriginalsRoot, newAbs)
		slog.Info("folder.move", "from", oldRel, "to", newRel)
		// Reindex both the old and new parents so PhotoPrism drops the moved
		// rows from the source view and picks them up under the destination.
		fireReindex(cfg, pp, token, "/"+filepath.Dir(oldRel))
		fireReindex(cfg, pp, token, "/"+filepath.Dir(newRel))
		c.JSON(http.StatusOK, gin.H{
			"ok":      true,
			"oldPath": oldRel,
			"newPath": newRel,
		})
	}
}