package identityprovider

import (
	"net/http"
	"strconv"
	"strings"

	"github.com/gin-gonic/gin"
	"vpn-platform/backend/internal/model"
	"vpn-platform/backend/internal/service"
	"vpn-platform/backend/internal/store"
)

func managedTunnel(c *gin.Context) (model.Tunnel, model.IdentityProvider, string, bool) {
	id, err := strconv.ParseUint(c.Param("id"), 10, 32)
	if err != nil || id == 0 {
		c.JSON(400, gin.H{"error": "无效专线"})
		return model.Tunnel{}, model.IdentityProvider{}, "", false
	}
	var tunnel model.Tunnel
	if store.DB.First(&tunnel, id).Error != nil {
		c.JSON(404, gin.H{"error": "专线不存在"})
		return tunnel, model.IdentityProvider{}, "", false
	}
	cfg, err := store.TunnelConfig(&tunnel)
	if err != nil || tunnel.Protocol != "openvpn" || service.Str(cfg, "auth_mode") != "oidc" || service.Str(cfg, "oidc_provider") != "builtin" {
		c.JSON(400, gin.H{"error": "仅支持内置飞书 OpenVPN 专线"})
		return tunnel, model.IdentityProvider{}, "", false
	}
	idp, base, err := enabled()
	if err != nil || service.Str(cfg, "oidc_issuer") != base || service.Str(cfg, "oidc_client_id") != idp.ClientID {
		c.JSON(409, gin.H{"error": "专线与当前飞书身份服务不匹配"})
		return tunnel, idp, base, false
	}
	return tunnel, idp, base, true
}

func (p *Provider) Profiles(c *gin.Context) {
	noStore(c)
	idp, base, err := enabled()
	if err != nil {
		c.JSON(409, gin.H{"error": "飞书身份服务未启用"})
		return
	}
	var profiles []model.IdentityProfile
	if err := store.DB.Where("issuer = ? AND app_id = ?", base, idp.AppID).Order("updated_at desc").Limit(500).Find(&profiles).Error; err != nil {
		c.JSON(500, gin.H{"error": "查询用户失败"})
		return
	}
	items := make([]gin.H, 0, len(profiles))
	for _, profile := range profiles {
		items = append(items, gin.H{"subject": profile.Subject, "name": profile.Name, "updated_at": profile.UpdatedAt})
	}
	c.JSON(200, gin.H{"profiles": items})
}

func (p *Provider) Grants(c *gin.Context) {
	noStore(c)
	tunnel, idp, base, ok := managedTunnel(c)
	if !ok {
		return
	}
	var grants []model.FeishuTunnelGrant
	if err := store.DB.Where("tunnel_id = ? AND issuer = ? AND app_id = ?", tunnel.ID, base, idp.AppID).Order("created_at desc").Find(&grants).Error; err != nil {
		c.JSON(500, gin.H{"error": "查询授权失败"})
		return
	}
	if grants == nil {
		grants = []model.FeishuTunnelGrant{}
	}
	c.JSON(200, gin.H{"grants": grants})
}

func (p *Provider) AddGrant(c *gin.Context) {
	noStore(c)
	tunnel, idp, base, ok := managedTunnel(c)
	if !ok {
		return
	}
	var input struct {
		Subject string `json:"subject"`
	}
	if c.ShouldBindJSON(&input) != nil || len(input.Subject) > 256 || !strings.HasPrefix(input.Subject, idp.TenantKey+":ou_") {
		c.JSON(400, gin.H{"error": "请选择已验证的飞书成员"})
		return
	}
	var profile model.IdentityProfile
	if store.DB.Where("issuer = ? AND app_id = ? AND subject = ?", base, idp.AppID, input.Subject).First(&profile).Error != nil {
		c.JSON(400, gin.H{"error": "用户尚未完成飞书验证"})
		return
	}
	grant := model.FeishuTunnelGrant{TunnelID: tunnel.ID, Issuer: base, AppID: idp.AppID, Subject: input.Subject}
	if err := store.DB.Where(&model.FeishuTunnelGrant{TunnelID: tunnel.ID, Issuer: base, AppID: idp.AppID, Subject: input.Subject}).FirstOrCreate(&grant).Error; err != nil {
		c.JSON(500, gin.H{"error": "授权失败"})
		return
	}
	store.Audit(c.GetString("username"), "feishu_grant_added", tunnel.Name, input.Subject)
	c.JSON(http.StatusOK, gin.H{"grant": grant})
}

func (p *Provider) DeleteGrant(c *gin.Context) {
	noStore(c)
	tunnel, idp, base, ok := managedTunnel(c)
	if !ok {
		return
	}
	grantID, err := strconv.ParseUint(c.Param("grant_id"), 10, 32)
	if err != nil || grantID == 0 {
		c.JSON(400, gin.H{"error": "无效授权"})
		return
	}
	var grant model.FeishuTunnelGrant
	if store.DB.Where("id = ? AND tunnel_id = ? AND issuer = ? AND app_id = ?", grantID, tunnel.ID, base, idp.AppID).First(&grant).Error != nil {
		c.JSON(404, gin.H{"error": "授权不存在"})
		return
	}
	if err := store.DB.Delete(&grant).Error; err != nil {
		c.JSON(500, gin.H{"error": "撤销失败"})
		return
	}
	store.Audit(c.GetString("username"), "feishu_grant_removed", tunnel.Name, grant.Subject)
	c.Status(204)
}

func (p *Provider) DirectoryCheck(c *gin.Context) {
	noStore(c)
	if !secureAdmin(c) {
		c.JSON(403, gin.H{"error": "请通过可信 HTTPS 管理入口检查权限"})
		return
	}
	idp, base, err := enabled()
	if err != nil {
		c.JSON(409, gin.H{"error": "飞书身份服务未启用"})
		return
	}
	var input struct {
		Subject string `json:"subject"`
	}
	if c.ShouldBindJSON(&input) != nil || len(input.Subject) > 256 || !strings.HasPrefix(input.Subject, idp.TenantKey+":ou_") {
		c.JSON(400, gin.H{"error": "请选择已验证的飞书成员"})
		return
	}
	var profile model.IdentityProfile
	if store.DB.Where("issuer = ? AND app_id = ? AND subject = ?", base, idp.AppID, input.Subject).First(&profile).Error != nil {
		c.JSON(404, gin.H{"error": "用户尚未完成飞书验证"})
		return
	}
	secret, err := store.DecryptSecret(idp.AppSecret)
	if err != nil {
		c.JSON(503, gin.H{"error": "读取飞书配置失败"})
		return
	}
	name, source, err := fetchDirectoryNameWithSource(c.Request.Context(), idp.AppID, secret, strings.TrimPrefix(input.Subject, idp.TenantKey+":"))
	if err != nil {
		c.JSON(200, gin.H{"available": false, "hint": "请在飞书开放平台检查 contact:user.base:readonly 权限、应用发布状态和通讯录可见范围"})
		return
	}
	c.JSON(200, gin.H{"available": true, "name": name, "source": source})
}