package auth

import (
	"net/http"
	"time"

	"tyto/internal/database"

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

// RolesAPI provides HTTP handlers for role management.
type RolesAPI struct {
	db   database.Database
	auth *Authorizer
}

// NewRolesAPI creates a new roles API handler.
func NewRolesAPI(db database.Database, auth *Authorizer) *RolesAPI {
	return &RolesAPI{
		db:   db,
		auth: auth,
	}
}

// RegisterRoutes registers role management routes.
func (a *RolesAPI) RegisterRoutes(group *gin.RouterGroup, authMiddleware *Middleware) {
	roles := group.Group("/roles")
	roles.Use(authMiddleware.Required())
	{
		// View roles (requires roles:view)
		roles.GET("", a.auth.RequirePermission(PermRolesView), a.handleListRoles)
		roles.GET("/:id", a.auth.RequirePermission(PermRolesView), a.handleGetRole)

		// Manage roles (requires roles:manage)
		roles.POST("", a.auth.RequirePermission(PermRolesManage), a.handleCreateRole)
		roles.PUT("/:id", a.auth.RequirePermission(PermRolesManage), a.handleUpdateRole)
		roles.DELETE("/:id", a.auth.RequirePermission(PermRolesManage), a.handleDeleteRole)
	}
}

// RoleResponse represents a role in API responses.
type RoleResponse struct {
	ID          string   `json:"id"`
	Name        string   `json:"name"`
	Description string   `json:"description,omitempty"`
	Permissions []string `json:"permissions"`
	IsSystem    bool     `json:"isSystem"`
	CreatedAt   string   `json:"createdAt"`
}

func roleToResponse(r *database.Role) RoleResponse {
	return RoleResponse{
		ID:          r.ID,
		Name:        r.Name,
		Description: r.Description,
		Permissions: r.Permissions,
		IsSystem:    r.IsSystem,
		CreatedAt:   r.CreatedAt.Format(time.RFC3339),
	}
}

func (a *RolesAPI) handleListRoles(c *gin.Context) {
	roles, err := a.db.ListRoles(c.Request.Context())
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "failed to list roles"})
		return
	}

	response := make([]RoleResponse, len(roles))
	for i, r := range roles {
		response[i] = roleToResponse(r)
	}

	c.JSON(http.StatusOK, response)
}

func (a *RolesAPI) handleGetRole(c *gin.Context) {
	id := c.Param("id")

	role, err := a.db.GetRole(c.Request.Context(), id)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "failed to get role"})
		return
	}

	if role == nil {
		c.JSON(http.StatusNotFound, gin.H{"error": "role not found"})
		return
	}

	c.JSON(http.StatusOK, roleToResponse(role))
}

// CreateRoleRequest represents a role creation request.
type CreateRoleRequest struct {
	Name        string   `json:"name" binding:"required,min=2,max=64"`
	Description string   `json:"description"`
	Permissions []string `json:"permissions" binding:"required,min=1"`
}

func (a *RolesAPI) handleCreateRole(c *gin.Context) {
	var req CreateRoleRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid request"})
		return
	}

	// Validate permissions
	if !a.validatePermissions(req.Permissions) {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid permissions"})
		return
	}

	role := &database.Role{
		ID:          generateID(),
		Name:        req.Name,
		Description: req.Description,
		Permissions: req.Permissions,
		IsSystem:    false,
		CreatedAt:   time.Now().UTC(),
	}

	if err := a.db.CreateRole(c.Request.Context(), role); err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "failed to create role"})
		return
	}

	c.JSON(http.StatusCreated, roleToResponse(role))
}

// UpdateRoleRequest represents a role update request.
type UpdateRoleRequest struct {
	Name        string   `json:"name" binding:"required,min=2,max=64"`
	Description string   `json:"description"`
	Permissions []string `json:"permissions" binding:"required,min=1"`
}

func (a *RolesAPI) handleUpdateRole(c *gin.Context) {
	id := c.Param("id")

	role, err := a.db.GetRole(c.Request.Context(), id)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "failed to get role"})
		return
	}

	if role == nil {
		c.JSON(http.StatusNotFound, gin.H{"error": "role not found"})
		return
	}

	if role.IsSystem {
		c.JSON(http.StatusForbidden, gin.H{"error": "cannot modify system role"})
		return
	}

	var req UpdateRoleRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid request"})
		return
	}

	// Validate permissions
	if !a.validatePermissions(req.Permissions) {
		c.JSON(http.StatusBadRequest, gin.H{"error": "invalid permissions"})
		return
	}

	role.Name = req.Name
	role.Description = req.Description
	role.Permissions = req.Permissions

	if err := a.db.UpdateRole(c.Request.Context(), role); err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "failed to update role"})
		return
	}

	c.JSON(http.StatusOK, roleToResponse(role))
}

func (a *RolesAPI) handleDeleteRole(c *gin.Context) {
	id := c.Param("id")

	role, err := a.db.GetRole(c.Request.Context(), id)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "failed to get role"})
		return
	}

	if role == nil {
		c.JSON(http.StatusNotFound, gin.H{"error": "role not found"})
		return
	}

	if role.IsSystem {
		c.JSON(http.StatusForbidden, gin.H{"error": "cannot delete system role"})
		return
	}

	if err := a.db.DeleteRole(c.Request.Context(), id); err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "failed to delete role"})
		return
	}

	c.JSON(http.StatusOK, gin.H{"message": "role deleted"})
}

// validatePermissions checks if all permissions are valid.
func (a *RolesAPI) validatePermissions(perms []string) bool {
	validPerms := make(map[string]bool)
	for _, p := range AllPermissions() {
		validPerms[string(p)] = true
	}
	validPerms["*"] = true // Wildcard is valid

	for _, p := range perms {
		// Check exact match
		if validPerms[p] {
			continue
		}

		// Check category wildcard (e.g., "agents:*")
		if len(p) > 2 && p[len(p)-2:] == ":*" {
			prefix := p[:len(p)-1]
			found := false
			for valid := range validPerms {
				if len(valid) > len(prefix) && valid[:len(prefix)] == prefix {
					found = true
					break
				}
			}
			if found {
				continue
			}
		}

		return false
	}

	return true
}