package api

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

	"github.com/gin-gonic/gin"
	"github.com/openteam/server/internal/pkg/resp"
	"github.com/openteam/server/internal/store"
	"gorm.io/gorm"
	"gorm.io/gorm/clause"
)

// AdminUsers GET /api/v1/admin/users — 用户列表（搜索、分页）。
func (h *Handler) AdminUsers(c *gin.Context) {
	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
	size, _ := strconv.Atoi(c.DefaultQuery("page_size", "20"))
	if page < 1 {
		page = 1
	}
	if size < 1 || size > 100 {
		size = 20
	}
	q := h.a.DB.Model(&store.User{})
	if kw := c.Query("q"); kw != "" {
		q = q.Where("username LIKE ? OR email LIKE ?", "%"+kw+"%", "%"+kw+"%")
	}
	var total int64
	q.Count(&total)
	var users []store.User
	q.Order("id DESC").Offset((page - 1) * size).Limit(size).Find(&users)
	out := make([]gin.H, 0, len(users))
	for _, u := range users {
		out = append(out, h.publicUser(&u))
	}
	resp.OK(c, gin.H{"items": out, "total": total, "page": page, "page_size": size})
}

// AdminPatchUser PATCH /api/v1/admin/users/:id — 角色/状态。
func (h *Handler) AdminPatchUser(c *gin.Context) {
	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
	if err != nil {
		resp.Fail(c, http.StatusBadRequest, "invalid user id")
		return
	}
	var req struct {
		Role   *string `json:"role"`
		Status *string `json:"status"`
	}
	if err := c.ShouldBindJSON(&req); err != nil {
		resp.Fail(c, http.StatusBadRequest, "invalid input")
		return
	}
	updates := map[string]any{}
	if req.Role != nil {
		if *req.Role != store.RoleUser && *req.Role != store.RoleAdmin {
			resp.Fail(c, http.StatusBadRequest, "role must be user or admin")
			return
		}
		updates["role"] = *req.Role
	}
	if req.Status != nil {
		if *req.Status != store.UserStatusActive && *req.Status != store.UserStatusDisabled {
			resp.Fail(c, http.StatusBadRequest, "status must be active or disabled")
			return
		}
		updates["status"] = *req.Status
	}
	if len(updates) == 0 {
		resp.OK(c, gin.H{"ok": true})
		return
	}
	res := h.a.DB.Model(&store.User{}).Where("id = ?", id).Updates(updates)
	if res.Error != nil {
		resp.Fail(c, http.StatusInternalServerError, "failed to update user")
		return
	}
	if res.RowsAffected == 0 {
		resp.Fail(c, http.StatusNotFound, "user not found")
		return
	}
	resp.OK(c, gin.H{"ok": true})
}

// AdminAdjustBalance POST /api/v1/admin/users/:id/balance — 手动调余额（写流水）。
func (h *Handler) AdminAdjustBalance(c *gin.Context) {
	admin := sessionUser(c)
	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
	if err != nil {
		resp.Fail(c, http.StatusBadRequest, "invalid user id")
		return
	}
	var req struct {
		Amount float64 `json:"amount" binding:"required"`
		Remark string  `json:"remark"`
	}
	if err := c.ShouldBindJSON(&req); err != nil {
		resp.Fail(c, http.StatusBadRequest, "invalid input: amount required")
		return
	}
	if req.Amount == 0 {
		resp.Fail(c, http.StatusBadRequest, "amount must not be zero")
		return
	}

	err = h.a.DB.Transaction(func(tx *gorm.DB) error {
		var u store.User
		if err := tx.Clauses(clause.Locking{Strength: "UPDATE"}).First(&u, id).Error; err != nil {
			return err
		}
		newBalance := u.Balance + req.Amount
		if err := tx.Model(&store.User{}).Where("id = ?", id).Update("balance", newBalance).Error; err != nil {
			return err
		}
		ref := "admin:" + strconv.FormatUint(u.ID, 10) + ":" + time.Now().Format("20060102150405")
		_ = admin.ID // 流水里不冗余管理员 ID；需要时再加
		return tx.Create(&store.BalanceLog{
			UserID:       u.ID,
			Change:       req.Amount,
			BalanceAfter: newBalance,
			Type:         store.BalanceTypeAdminAdjust,
			RefID:        ref,
			Remark:       req.Remark,
		}).Error
	})
	if err != nil {
		resp.Fail(c, http.StatusNotFound, "user not found or failed to adjust")
		return
	}
	resp.OK(c, gin.H{"ok": true})
}

// AdminConfig GET /api/v1/admin/config — 全部系统配置。
func (h *Handler) AdminConfig(c *gin.Context) {
	var cfgs []store.SystemConfig
	if err := h.a.DB.Find(&cfgs).Error; err != nil {
		resp.Fail(c, http.StatusInternalServerError, "failed to load config")
		return
	}
	out := gin.H{}
	for _, cfg := range cfgs {
		out[cfg.Key] = json.RawMessage(cfg.Value)
	}
	resp.OK(c, gin.H{"config": out})
}

// AdminPutConfig PUT /api/v1/admin/config — 整表覆盖（upsert）。
func (h *Handler) AdminPutConfig(c *gin.Context) {
	var req map[string]json.RawMessage
	if err := c.ShouldBindJSON(&req); err != nil {
		resp.Fail(c, http.StatusBadRequest, "invalid input")
		return
	}
	err := h.a.DB.Transaction(func(tx *gorm.DB) error {
		for k, v := range req {
			cfg := store.SystemConfig{Key: k, Value: string(v)}
			if err := tx.Save(&cfg).Error; err != nil {
				return err
			}
		}
		return nil
	})
	if err != nil {
		resp.Fail(c, http.StatusInternalServerError, "failed to save config")
		return
	}
	resp.OK(c, gin.H{"ok": true})
}