package admin

import (
	"net/http"
	"strconv"

	"github.com/Wei-Shaw/sub2api/internal/pkg/pagination"
	"github.com/Wei-Shaw/sub2api/internal/pkg/response"
	"github.com/Wei-Shaw/sub2api/internal/service"

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

// SoraHandler handles admin Sora statistics and management
type SoraHandler struct {
	soraGenService   *service.SoraGenerationService
	soraQuotaService *service.SoraQuotaService
	userRepo         service.UserRepository
}

// NewSoraHandler creates a new admin Sora handler
func NewSoraHandler(
	soraGenService *service.SoraGenerationService,
	soraQuotaService *service.SoraQuotaService,
	userRepo service.UserRepository,
) *SoraHandler {
	return &SoraHandler{
		soraGenService:   soraGenService,
		soraQuotaService: soraQuotaService,
		userRepo:         userRepo,
	}
}

// SoraSystemStatsResponse 系统级 Sora 统计
type SoraSystemStatsResponse struct {
	TotalUsers        int64            `json:"total_users"`
	TotalGenerations  int64            `json:"total_generations"`
	TotalStorageBytes int64            `json:"total_storage_bytes"`
	ActiveGenerations int64            `json:"active_generations"`
	ByStatus          map[string]int64 `json:"by_status"`
	ByModel           map[string]int64 `json:"by_model"`
}

// GetSystemStats 获取 Sora 系统统计
// GET /api/v1/admin/sora/stats
func (h *SoraHandler) GetSystemStats(c *gin.Context) {
	ctx := c.Request.Context()

	// 获取所有用户的 Sora 统计
	users, _, err := h.userRepo.List(ctx, pagination.PaginationParams{Page: 1, PageSize: 10000})
	if err != nil {
		response.Error(c, 500, "Failed to get users")
		return
	}

	var totalStorageBytes int64
	byStatus := make(map[string]int64)
	byModel := make(map[string]int64)

	// 遍历用户统计
	// NOTE: Per-user storage tracking removed; totalStorageBytes now sourced from SoraGenerationService if needed.
	_ = users // suppress unused warning until real aggregation is implemented

	resp := SoraSystemStatsResponse{
		TotalUsers:        int64(len(users)),
		TotalGenerations:  0,
		TotalStorageBytes: totalStorageBytes,
		ActiveGenerations: 0,
		ByStatus:          byStatus,
		ByModel:           byModel,
	}

	response.Success(c, resp)
}

// SoraUserStatsResponse 用户级 Sora 统计
type SoraUserStatsResponse struct {
	UserID             int64  `json:"user_id"`
	Username           string `json:"username"`
	Email              string `json:"email"`
	QuotaBytes         int64  `json:"quota_bytes"`
	UsedBytes          int64  `json:"used_bytes"`
	AvailableBytes     int64  `json:"available_bytes"`
	QuotaSource        string `json:"quota_source"`
	GenerationsCount   int64  `json:"generations_count"`
	ActiveCount        int64  `json:"active_count"`
	TotalFileSizeBytes int64  `json:"total_file_size_bytes"`
}

// ListUserStats 获取用户 Sora 使用统计列表
// GET /api/v1/admin/sora/users
func (h *SoraHandler) ListUserStats(c *gin.Context) {
	ctx := c.Request.Context()
	page, pageSize := response.ParsePagination(c)
	search := c.Query("search")

	filters := service.UserListFilters{
		Search: search,
	}

	users, result, err := h.userRepo.ListWithFilters(ctx, pagination.PaginationParams{
		Page:     page,
		PageSize: pageSize,
	}, filters)
	if err != nil {
		response.Error(c, 500, "Failed to get users")
		return
	}

	results := make([]SoraUserStatsResponse, len(users))
	for i, u := range users {
		quota, _ := h.soraQuotaService.GetQuota(ctx, u.ID)
		activeCount, _ := h.soraGenService.CountActiveByUser(ctx, u.ID)

		quotaBytes := int64(0)
		availableBytes := int64(0)
		quotaSource := "unlimited"

		if quota != nil {
			quotaBytes = quota.QuotaBytes
			availableBytes = quota.AvailableBytes
			quotaSource = quota.QuotaSource
		}

		results[i] = SoraUserStatsResponse{
			UserID:             u.ID,
			Username:           u.Username,
			Email:              u.Email,
			QuotaBytes:         quotaBytes,
			UsedBytes:          0, // per-user usage removed; use SoraGenerationService for real data
			AvailableBytes:     availableBytes,
			QuotaSource:        quotaSource,
			GenerationsCount:   0,
			ActiveCount:        activeCount,
			TotalFileSizeBytes: 0, // per-user usage removed; use SoraGenerationService for real data
		}
	}

	response.Paginated(c, results, result.Total, page, pageSize)
}

// SoraGenerationAdminResponse 管理员视角的生成记录
type SoraGenerationAdminResponse struct {
	ID            int64   `json:"id"`
	UserID        int64   `json:"user_id"`
	Username      string  `json:"username"`
	Email         string  `json:"email"`
	Model         string  `json:"model"`
	Prompt        string  `json:"prompt"`
	MediaType     string  `json:"media_type"`
	Status        string  `json:"status"`
	StorageType   string  `json:"storage_type"`
	MediaURL      string  `json:"media_url"`
	FileSizeBytes int64   `json:"file_size_bytes"`
	ErrorMessage  string  `json:"error_message"`
	CreatedAt     string  `json:"created_at"`
	CompletedAt   *string `json:"completed_at"`
}

// ListGenerations 获取 Sora 生成记录列表（管理员视角）
// GET /api/v1/admin/sora/generations
func (h *SoraHandler) ListGenerations(c *gin.Context) {
	// 简化实现：返回空列表
	// 完整实现需要扩展 repository 支持 admin 级别的查询
	response.Paginated(c, []SoraGenerationAdminResponse{}, int64(0), 1, 20)
}

// ClearUserStorage 清除用户的 Sora 存储空间（已弃用）。
//
// Deprecated: Per-user storage tracking has been removed.
// This endpoint now returns 410 Gone. Per-user Sora storage quota tracking was
// fully removed in the Sora storage refactoring. Storage management is now
// handled at the system-default level via SoraQuotaService.
//
// DELETE /api/v1/admin/sora/users/:id/storage
func (h *SoraHandler) ClearUserStorage(c *gin.Context) {
	userID, err := strconv.ParseInt(c.Param("id"), 10, 64)
	if err != nil {
		response.BadRequest(c, "Invalid user ID")
		return
	}

	// Verify user exists before responding
	ctx := c.Request.Context()
	if _, err := h.userRepo.GetByID(ctx, userID); err != nil {
		response.ErrorFrom(c, err)
		return
	}

	c.Header("Deprecation", "true")
	c.Header("Sunset", "2026-12-31")
	c.Header("Warning", `299 - "Gone: per-user storage tracking removed, see SoraQuotaService"`)
	c.JSON(http.StatusGone, gin.H{
		"error":     "This endpoint is no longer available",
		"message":   "Per-user Sora storage quota tracking has been removed. Storage is now managed at system level.",
		"sunset":    "2026-12-31",
		"deprecated": true,
	})
}