package main

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

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

// PpLabel mirrors the shape PhotoPrism's /api/v1/labels endpoint returns.
// We decode enough to filter + recalculate PhotoCount; fields the client
// doesn't render are skipped for token efficiency.
type PpLabel struct {
	UID        string `json:"UID"`
	Name       string `json:"Name"`
	Slug       string `json:"Slug"`
	CustomSlug string `json:"CustomSlug"`
	Priority   int    `json:"Priority"`
	Favorite   bool   `json:"Favorite"`
	PhotoCount int    `json:"PhotoCount"`
	Thumb      string `json:"Thumb"`
	CreatedAt  string `json:"CreatedAt"`
	UpdatedAt  string `json:"UpdatedAt"`
}

// handleLabels proxies PhotoPrism's /api/v1/labels and then post-filters
// each label's PhotoCount (and removes labels with zero count) so they
// reflect only photos under the caller's BasePath.
//
// Route: GET /api/sidecar/labels  (behind requireSession)
func handleLabels(pp *ppClient, ppDb *gorm.DB) gin.HandlerFunc {
	return func(c *gin.Context) {
		token := ctxToken(c)
		basePath := ctxBasePath(c)

		// Forward the query string (count, offset, q, all, …) to PhotoPrism.
		query := c.Request.URL.RawQuery

		// Call PhotoPrism's labels endpoint using the caller's token.
		resp, err := pp.call(c.Request.Context(), http.MethodGet, "/api/v1/labels?"+query, token, nil)
		if err != nil || !resp.OK {
			c.JSON(http.StatusBadGateway, gin.H{"error": "upstream labels request failed"})
			return
		}

		// Decode labels.
		var labels []PpLabel
		if err := json.Unmarshal(resp.Body, &labels); err != nil {
			c.JSON(http.StatusInternalServerError, gin.H{"error": "failed to parse labels"})
			return
		}

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

		// One query: count + a representative scoped thumb for every label
		// the user can see. Replaces N per-label queries with a single JOIN.
		prefix := basePath + "/%"

		type labelStat struct {
			LabelUID  string `gorm:"column:label_uid"`
			Cnt       int64  `gorm:"column:cnt"`
			ThumbHash string `gorm:"column:thumb_hash"`
		}
		var stats []labelStat
		if err := ppDb.Raw(`
			SELECT lb.label_uid                          AS label_uid,
			       COUNT(DISTINCT p.id)                  AS cnt,
			       COALESCE(MIN(f.file_hash), '')        AS thumb_hash
			FROM   photos_labels pl
			JOIN   photos p  ON pl.photo_id  = p.id
			JOIN   labels lb ON pl.label_id  = lb.id
			LEFT JOIN files f ON f.photo_uid   = p.photo_uid
			                 AND f.file_primary = 1
			                 AND f.file_missing = 0
			WHERE  (p.photo_path = ? OR p.photo_path LIKE ?)
			  AND  p.deleted_at IS NULL
			GROUP  BY lb.label_uid
			HAVING cnt > 0
		`, basePath, prefix).Scan(&stats).Error; err != nil {
			c.JSON(http.StatusBadGateway, gin.H{"error": "label stats query failed"})
			return
		}

		cntMap := make(map[string]int64, len(stats))
		thumbMap := make(map[string]string, len(stats))
		for _, s := range stats {
			cntMap[s.LabelUID] = s.Cnt
			thumbMap[s.LabelUID] = s.ThumbHash
		}

		filtered := make([]PpLabel, 0, len(stats))
		for _, l := range labels {
			cnt, ok := cntMap[l.UID]
			if !ok || cnt == 0 {
				continue
			}
			l.PhotoCount = int(cnt)
			if th := thumbMap[l.UID]; th != "" {
				l.Thumb = th
			}
			filtered = append(filtered, l)
		}

		c.JSON(http.StatusOK, filtered)
	}
}

// Now also handle the session/config count scoping.

// PpCounts mirrors PhotoPrism's session config.count block that drives
// the sidebar badges (review, archive, all, etc.).
type PpCounts struct {
	All      int `json:"all"`
	Photos   int `json:"photos"`
	Media    int `json:"media"`
	Videos   int `json:"videos"`
	Review   int `json:"review"`
	Archived int `json:"archived"`
	Hidden   int `json:"hidden"`
	Private  int `json:"private"`
	Favorites int `json:"favorites"`
}

// handleScopedCounts returns user-scoped counts for review/archive/all
// so the sidebar badges match what the user actually sees.
//
// Route: GET /api/sidecar/counts  (behind requireSession)
func handleScopedCounts(ppDb *gorm.DB) gin.HandlerFunc {
	return func(c *gin.Context) {
		basePath := ctxBasePath(c)
		if basePath == "" || ppDb == nil {
			// Admin or no DB — can't scope, return empty.
			c.JSON(http.StatusOK, PpCounts{})
			return
		}

		prefix := basePath + "/%"
		pathCond := "(p.photo_path = ? OR p.photo_path LIKE ?)"
		args := []any{basePath, prefix}

		var counts PpCounts

		// All non-deleted photos in this user's scope.
		ppDb.Raw(`SELECT COUNT(*) FROM photos p WHERE p.deleted_at IS NULL AND `+pathCond, args...).Scan(&counts.All)

		// Photos needing review (quality < 3).
		ppDb.Raw(`SELECT COUNT(*) FROM photos p WHERE p.deleted_at IS NULL AND p.photo_quality < 3 AND `+pathCond, args...).Scan(&counts.Review)

		// Archived (soft-deleted) photos.
		ppDb.Raw(`SELECT COUNT(*) FROM photos p WHERE p.deleted_at IS NOT NULL AND `+pathCond, args...).Scan(&counts.Archived)

		// Private photos.
		ppDb.Raw(`SELECT COUNT(*) FROM photos p WHERE p.deleted_at IS NULL AND p.photo_private = 1 AND `+pathCond, args...).Scan(&counts.Private)

		// Photos (type image).
		ppDb.Raw(`SELECT COUNT(*) FROM photos p WHERE p.deleted_at IS NULL AND p.photo_type IN ('image','raw','live','animated') AND `+pathCond, args...).Scan(&counts.Photos)

		// Videos.
		ppDb.Raw(`SELECT COUNT(*) FROM photos p WHERE p.deleted_at IS NULL AND p.photo_type IN ('video','hdr','burst','live') AND `+pathCond, args...).Scan(&counts.Videos)

		// Favorites.
		ppDb.Raw(`SELECT COUNT(*) FROM photos p WHERE p.deleted_at IS NULL AND p.photo_favorite = 1 AND `+pathCond, args...).Scan(&counts.Favorites)

		c.JSON(http.StatusOK, counts)
	}
}