package main

import (
	"encoding/json"
	"net/http"
	"strings"

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

// handleFoldersProxy proxies PhotoPrism's /api/v1/folders/originals and
// post-filters by the caller's BasePath so the folder tree only shows
// folders under the user's library root.
//
// Route: GET /api/sidecar/folders  (behind requireSession)
func handleFoldersProxy(pp *ppClient) gin.HandlerFunc {
	return func(c *gin.Context) {
		token := ctxToken(c)
		basePath := ctxBasePath(c)

		// Forward query params to PhotoPrism.
		query := c.Request.URL.RawQuery
		if query == "" {
			query = "recursive=true&uncached=true&files=false"
		}

		resp, err := pp.call(c.Request.Context(), http.MethodGet, "/api/v1/folders/originals?"+query, token, nil)
		if err != nil || !resp.OK {
			c.JSON(http.StatusBadGateway, gin.H{"error": "upstream folders request failed"})
			return
		}

		// Decode the response — PhotoPrism returns { folders: [...] }.
		var payload struct {
			Folders []map[string]any `json:"folders"`
		}
		if err := json.Unmarshal(resp.Body, &payload); err != nil {
			c.Data(resp.Status, "application/json", resp.Body)
			return
		}

		// If the user has no BasePath (admin/empty), return as-is.
		if basePath == "" {
			c.JSON(http.StatusOK, payload)
			return
		}

		prefix := basePath + "/"

		// Post-filter folders by Path field only — frontend handles BasePath
		// prefix stripping via toUserPath().
		filtered := make([]map[string]any, 0, len(payload.Folders))
		for _, f := range payload.Folders {
			rawPath, ok := f["Path"]
			if !ok {
				continue
			}
			pathStr, ok := rawPath.(string)
			if !ok {
				continue
			}
			// Keep only folders under the user's base path.
			if pathStr == basePath || strings.HasPrefix(pathStr, prefix) {
				filtered = append(filtered, f)
			}
		}

		c.JSON(http.StatusOK, gin.H{"folders": filtered})
	}
}