package controllers

import (
	"net/http"
	"strings"

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

	"fotbal-club/internal/models"
	"fotbal-club/internal/services"
)

type EngagementController struct{ DB *gorm.DB }

func NewEngagementController(db *gorm.DB) *EngagementController { return &EngagementController{DB: db} }

// GET /api/v1/engagement/profile (auth)
func (ec *EngagementController) GetProfile(c *gin.Context) {
	uid, _ := c.Get("userID")
	userID := uid.(uint)
	svc := services.NewEngagementService(ec.DB)
	up, err := svc.EnsureProfile(userID)
	if err != nil { c.JSON(http.StatusInternalServerError, gin.H{"error":"Failed to load profile"}); return }
	// Achievements count
	var achCount int64
	_ = ec.DB.Model(&models.UserAchievement{}).Where("user_id = ?", userID).Count(&achCount).Error
	c.JSON(http.StatusOK, gin.H{
		"user_id": userID,
		"points": up.Points,
		"level": up.Level,
		"xp": up.XP,
		"avatar_url": up.AvatarURL,
		"animated_avatar_url": up.AnimatedAvatarURL,
		"achievements": achCount,
	})
}

// PATCH /api/v1/engagement/avatar (auth)
func (ec *EngagementController) PatchAvatar(c *gin.Context) {
	uid, _ := c.Get("userID")
	userID := uid.(uint)
	var body struct{ AvatarURL *string `json:"avatar_url"`; AnimatedAvatarURL *string `json:"animated_avatar_url"` }
	if err := c.ShouldBindJSON(&body); err != nil { c.JSON(http.StatusBadRequest, gin.H{"error":"Invalid payload"}); return }
	updates := map[string]interface{}{}
	if body.AvatarURL != nil { updates["avatar_url"] = strings.TrimSpace(*body.AvatarURL) }
	if body.AnimatedAvatarURL != nil { updates["animated_avatar_url"] = strings.TrimSpace(*body.AnimatedAvatarURL) }
	if len(updates) == 0 { c.JSON(http.StatusBadRequest, gin.H{"error":"No changes"}); return }
	if err := ec.DB.Model(&models.UserProfile{}).Where("user_id = ?", userID).Updates(updates).Error; err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error":"Failed to update avatar"}); return
	}
	c.JSON(http.StatusOK, gin.H{"ok": true})
}

// GET /api/v1/engagement/rewards (public)
func (ec *EngagementController) GetRewards(c *gin.Context) {
	var items []models.RewardItem
	q := ec.DB.Where("active = ?", true)
	if err := q.Order("created_at DESC").Find(&items).Error; err != nil { c.JSON(http.StatusInternalServerError, gin.H{"error":"Failed to load rewards"}); return }
	c.JSON(http.StatusOK, items)
}

// POST /api/v1/engagement/redeem (auth)
func (ec *EngagementController) Redeem(c *gin.Context) {
	uid, _ := c.Get("userID")
	userID := uid.(uint)
	var body struct{ RewardID uint `json:"reward_id"` }
	if err := c.ShouldBindJSON(&body); err != nil || body.RewardID == 0 { c.JSON(http.StatusBadRequest, gin.H{"error":"Invalid payload"}); return }
	var item models.RewardItem
	if err := ec.DB.First(&item, body.RewardID).Error; err != nil { c.JSON(http.StatusNotFound, gin.H{"error":"Reward not found"}); return }
	if !item.Active { c.JSON(http.StatusBadRequest, gin.H{"error":"Reward is not active"}); return }
	if item.Stock == 0 { c.JSON(http.StatusBadRequest, gin.H{"error":"Out of stock"}); return }
	// Ensure profile
	svc := services.NewEngagementService(ec.DB)
	up, err := svc.EnsureProfile(userID)
	if err != nil { c.JSON(http.StatusInternalServerError, gin.H{"error":"Failed to load profile"}); return }
	if up.Points < item.CostPoints { c.JSON(http.StatusBadRequest, gin.H{"error":"Nedostatek bodů"}); return }
	// Transaction: deduct points, reduce stock, create redemption
	tx := ec.DB.Begin()
	if err := tx.Model(&models.UserProfile{}).Where("user_id = ? AND points >= ?", userID, item.CostPoints).UpdateColumn("points", gorm.Expr("points - ?", item.CostPoints)).Error; err != nil { tx.Rollback(); c.JSON(http.StatusInternalServerError, gin.H{"error":"Failed to deduct points"}); return }
	if item.Stock > 0 {
		if err := tx.Model(&models.RewardItem{}).Where("id = ? AND stock > 0", item.ID).UpdateColumn("stock", gorm.Expr("stock - 1")).Error; err != nil { tx.Rollback(); c.JSON(http.StatusInternalServerError, gin.H{"error":"Failed to update stock"}); return }
	}
	red := models.RewardRedemption{ UserID: userID, RewardID: item.ID, Status: "approved" }
	if strings.HasPrefix(item.Type, "merch_") || item.Type == "custom" { red.Status = "pending" }
	if err := tx.Create(&red).Error; err != nil { tx.Rollback(); c.JSON(http.StatusInternalServerError, gin.H{"error":"Failed to create redemption"}); return }
	// If avatar reward, update profile immediately
	if item.Type == "avatar_static" {
		_ = tx.Model(&models.UserProfile{}).Where("user_id = ?", userID).Update("avatar_url", item.ImageURL).Error
	}
	if item.Type == "avatar_animated" {
		_ = tx.Model(&models.UserProfile{}).Where("user_id = ?", userID).Update("animated_avatar_url", item.ImageURL).Error
	}
	if err := tx.Commit().Error; err != nil { c.JSON(http.StatusInternalServerError, gin.H{"error":"Failed to commit redemption"}); return }
	c.JSON(http.StatusOK, gin.H{"ok": true, "status": red.Status})
}

// GET /api/v1/engagement/achievements (auth)
func (ec *EngagementController) GetAchievements(c *gin.Context) {
    uid, _ := c.Get("userID")
    userID := uid.(uint)
    // Ensure defaults and award any newly satisfied achievements
    svc := services.NewEngagementService(ec.DB)
    _ = svc.CheckAndAwardAchievements(userID)

    // Load active achievement definitions
    var defs []models.Achievement
    _ = ec.DB.Where("active = ?", true).Order("id ASC").Find(&defs).Error

    // Load user's completed achievements
    var userAch []models.UserAchievement
    _ = ec.DB.Where("user_id = ?", userID).Find(&userAch).Error
    achieved := map[uint]models.UserAchievement{}
    for _, ua := range userAch { achieved[ua.AchievementID] = ua }

    // Counters for progress
    var commentCount int64
    _ = ec.DB.Model(&models.Comment{}).Where("user_id = ?", userID).Count(&commentCount).Error
    var voteCount int64
    _ = ec.DB.Model(&models.PollVote{}).Where("user_id = ?", userID).Count(&voteCount).Error
    hasNewsletter := false
    _ = ec.DB.Model(&models.NewsletterSubscription{}).Select("1").Where("LOWER(email) = (SELECT LOWER(email) FROM users WHERE id = ?) AND is_active = ?", userID, true).Limit(1).Scan(&hasNewsletter).Error

    // Build response
    items := make([]gin.H, 0, len(defs))
    for _, d := range defs {
        if ua, ok := achieved[d.ID]; ok {
            items = append(items, gin.H{
                "id": d.ID,
                "code": d.Code,
                "title": d.Title,
                "description": d.Description,
                "points": d.Points,
                "xp": d.XP,
                "icon": d.Icon,
                "achieved": true,
                "achieved_at": ua.CreatedAt,
            })
        } else {
            items = append(items, gin.H{
                "id": d.ID,
                "code": d.Code,
                "title": d.Title,
                "description": d.Description,
                "points": d.Points,
                "xp": d.XP,
                "icon": d.Icon,
                "achieved": false,
            })
        }
    }

    c.JSON(http.StatusOK, gin.H{
        "achievements": items,
        "counters": gin.H{
            "comments": commentCount,
            "votes": voteCount,
            "newsletter": hasNewsletter,
        },
    })
}

// Admin: list rewards
// GET /api/v1/admin/engagement/rewards
func (ec *EngagementController) AdminListRewards(c *gin.Context) {
    var items []models.RewardItem
    q := ec.DB.Model(&models.RewardItem{})
    if v := strings.TrimSpace(c.Query("active")); v != "" {
        if v == "true" || v == "1" { q = q.Where("active = ?", true) }
        if v == "false" || v == "0" { q = q.Where("active = ?", false) }
    }
    if err := q.Order("created_at DESC").Find(&items).Error; err != nil {
        c.JSON(http.StatusInternalServerError, gin.H{"error":"Failed to load rewards"}); return
    }
    c.JSON(http.StatusOK, gin.H{"items": items})
}

// Admin: create reward
// POST /api/v1/admin/engagement/rewards
func (ec *EngagementController) AdminCreateReward(c *gin.Context) {
    var body struct{
        Name string `json:"name"`
        Type string `json:"type"`
        CostPoints int64 `json:"cost_points"`
        ImageURL string `json:"image_url"`
        Stock int `json:"stock"`
        Active *bool `json:"active"`
        Metadata map[string]interface{} `json:"metadata"`
    }
    if err := c.ShouldBindJSON(&body); err != nil || strings.TrimSpace(body.Name) == "" || strings.TrimSpace(body.Type) == "" {
        c.JSON(http.StatusBadRequest, gin.H{"error":"Invalid payload"}); return
    }
    item := models.RewardItem{ Name: strings.TrimSpace(body.Name), Type: strings.TrimSpace(body.Type), CostPoints: body.CostPoints, ImageURL: strings.TrimSpace(body.ImageURL), Stock: body.Stock, Active: true }
    if body.Active != nil { item.Active = *body.Active }
    if body.Metadata != nil { item.Metadata = body.Metadata }
    if err := ec.DB.Create(&item).Error; err != nil { c.JSON(http.StatusInternalServerError, gin.H{"error":"Failed to create reward"}); return }
    c.JSON(http.StatusOK, item)
}

// Admin: update reward
// PUT /api/v1/admin/engagement/rewards/:id
func (ec *EngagementController) AdminUpdateReward(c *gin.Context) {
    id := c.Param("id")
    var body struct{
        Name *string `json:"name"`
        Type *string `json:"type"`
        CostPoints *int64 `json:"cost_points"`
        ImageURL *string `json:"image_url"`
        Stock *int `json:"stock"`
        Active *bool `json:"active"`
        Metadata map[string]interface{} `json:"metadata"`
    }
    if err := c.ShouldBindJSON(&body); err != nil { c.JSON(http.StatusBadRequest, gin.H{"error":"Invalid payload"}); return }
    updates := map[string]interface{}{}
    if body.Name != nil { updates["name"] = strings.TrimSpace(*body.Name) }
    if body.Type != nil { updates["type"] = strings.TrimSpace(*body.Type) }
    if body.CostPoints != nil { updates["cost_points"] = *body.CostPoints }
    if body.ImageURL != nil { updates["image_url"] = strings.TrimSpace(*body.ImageURL) }
    if body.Stock != nil { updates["stock"] = *body.Stock }
    if body.Active != nil { updates["active"] = *body.Active }
    if body.Metadata != nil { updates["metadata"] = body.Metadata }
    if len(updates) == 0 { c.JSON(http.StatusBadRequest, gin.H{"error":"No changes"}); return }
    if err := ec.DB.Model(&models.RewardItem{}).Where("id = ?", id).Updates(updates).Error; err != nil {
        c.JSON(http.StatusInternalServerError, gin.H{"error":"Failed to update reward"}); return
    }
    c.JSON(http.StatusOK, gin.H{"ok": true})
}

// Admin: delete reward
// DELETE /api/v1/admin/engagement/rewards/:id
func (ec *EngagementController) AdminDeleteReward(c *gin.Context) {
    id := c.Param("id")
    if err := ec.DB.Delete(&models.RewardItem{}, "id = ?", id).Error; err != nil {
        c.JSON(http.StatusInternalServerError, gin.H{"error":"Failed to delete reward"}); return
    }
    c.JSON(http.StatusOK, gin.H{"ok": true})
}

// Admin: list redemptions
// GET /api/v1/admin/engagement/redemptions
func (ec *EngagementController) AdminListRedemptions(c *gin.Context) {
    var items []models.RewardRedemption
    q := ec.DB.Model(&models.RewardRedemption{})
    if v := strings.TrimSpace(c.Query("status")); v != "" { q = q.Where("status = ?", v) }
    if err := q.Order("created_at DESC").Find(&items).Error; err != nil {
        c.JSON(http.StatusInternalServerError, gin.H{"error":"Failed to load redemptions"}); return
    }
    c.JSON(http.StatusOK, gin.H{"items": items})
}

// Admin: update redemption status (approve/reject/fulfill)
// PATCH /api/v1/admin/engagement/redemptions/:id
func (ec *EngagementController) AdminUpdateRedemptionStatus(c *gin.Context) {
    id := c.Param("id")
    var body struct{ Action string `json:"action"` }
    if err := c.ShouldBindJSON(&body); err != nil { c.JSON(http.StatusBadRequest, gin.H{"error":"Invalid payload"}); return }
    action := strings.ToLower(strings.TrimSpace(body.Action))
    var newStatus string
    switch action {
    case "approve": newStatus = "approved"
    case "reject": newStatus = "rejected"
    case "fulfill": newStatus = "fulfilled"
    default:
        c.JSON(http.StatusBadRequest, gin.H{"error":"Invalid action"}); return
    }
    if err := ec.DB.Model(&models.RewardRedemption{}).Where("id = ?", id).Update("status", newStatus).Error; err != nil {
        c.JSON(http.StatusInternalServerError, gin.H{"error":"Failed to update status"}); return
    }
    c.JSON(http.StatusOK, gin.H{"ok": true, "status": newStatus})
}