package v1

import (
	"net/http"
	"strconv"

	"github.com/gin-gonic/gin"

	"github.com/gochat/gochat/internal/model"
	"github.com/gochat/gochat/internal/repository"
	"github.com/gochat/gochat/pkg/response"
)

// PlatformAccountUserHandler handles Platform API account_user endpoints (AccessToken auth).
// Reference: Chatwoot Platform::Api::V1::AccountUsersController — AccessToken authenticated
//
// Manages the association between users and accounts from the Platform API context.
// Both the account and the user must be within the PlatformApp's permissible scope.
type PlatformAccountUserHandler struct {
	accountRepo     *repository.AccountRepo
	userRepo        *repository.UserRepo
	permissibleRepo *repository.PermissibleRepo
}

// NewPlatformAccountUserHandler creates a new PlatformAccountUser handler.
func NewPlatformAccountUserHandler(
	accountRepo *repository.AccountRepo,
	userRepo *repository.UserRepo,
	permissibleRepo *repository.PermissibleRepo,
) *PlatformAccountUserHandler {
	return &PlatformAccountUserHandler{
		accountRepo:     accountRepo,
		userRepo:        userRepo,
		permissibleRepo: permissibleRepo,
	}
}

// Index lists account_users for a specific account.
// GET /platform/api/v1/accounts/:account_id/account_users
// Reference: Chatwoot Platform::Api::V1::AccountUsersController#index
// Requires: Account must be within PlatformApp's permissible scope.
func (h *PlatformAccountUserHandler) Index(c *gin.Context) {
	accountID, err := parseUintAnyParam(c, "account_id", "id")
	if err != nil || accountID == 0 {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid account ID")
		return
	}

	platformAppID := getPlatformAppID(c)

	// Verify PlatformApp has permissible access to this account
	perm, err := h.permissibleRepo.FindByPlatformAppAndResource(c.Request.Context(), platformAppID, model.PermissibleTypeAccount, accountID)
	if err != nil || perm == nil {
		response.AbortWithStatusError(c, http.StatusForbidden, response.ErrForbidden, "non permissible resource")
		return
	}

	accountUsers, _, err := h.accountRepo.FindAgentsByAccount(c.Request.Context(), accountID, 0, 100)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusInternalServerError, response.ErrInternal, err.Error())
		return
	}

	c.JSON(http.StatusOK, accountUsers)
}

// Create adds a user to an account.
// POST /platform/api/v1/accounts/:account_id/account_users
// Reference: Chatwoot Platform::Api::V1::AccountUsersController#create
// Requires: Both account and user must be within PlatformApp's permissible scope.
func (h *PlatformAccountUserHandler) Create(c *gin.Context) {
	accountID, err := parseUintAnyParam(c, "account_id", "id")
	if err != nil || accountID == 0 {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid account ID")
		return
	}

	platformAppID := getPlatformAppID(c)

	// Verify PlatformApp has permissible access to this account
	perm, err := h.permissibleRepo.FindByPlatformAppAndResource(c.Request.Context(), platformAppID, model.PermissibleTypeAccount, accountID)
	if err != nil || perm == nil {
		response.AbortWithStatusError(c, http.StatusForbidden, response.ErrForbidden, "non permissible resource")
		return
	}

	var req struct {
		UserID uint    `json:"user_id" form:"user_id" binding:"required"`
		Role   *string `json:"role,omitempty" form:"role"`
	}
	if err := c.ShouldBind(&req); err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, err.Error())
		return
	}

	acctUser, err := h.accountRepo.UpsertAccountUser(c.Request.Context(), accountID, req.UserID, req.Role)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusInternalServerError, response.ErrInternal, err.Error())
		return
	}

	c.JSON(http.StatusOK, acctUser)
}

// Destroy removes a user from an account.
// DELETE /platform/api/v1/accounts/:account_id/account_users/:id
// Reference: Chatwoot Platform::Api::V1::AccountUsersController#destroy
// Requires: Account must be within PlatformApp's permissible scope.
func (h *PlatformAccountUserHandler) Destroy(c *gin.Context) {
	accountID, err := parseUintAnyParam(c, "account_id", "id")
	if err != nil || accountID == 0 {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid account ID")
		return
	}

	userID, err := platformAccountUserID(c)
	if err != nil || userID == 0 {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid user ID")
		return
	}

	platformAppID := getPlatformAppID(c)

	// Verify PlatformApp has permissible access to this account
	perm, err := h.permissibleRepo.FindByPlatformAppAndResource(c.Request.Context(), platformAppID, model.PermissibleTypeAccount, accountID)
	if err != nil || perm == nil {
		response.AbortWithStatusError(c, http.StatusForbidden, response.ErrForbidden, "non permissible resource")
		return
	}

	if err := h.accountRepo.RemoveUserFromAccount(c.Request.Context(), accountID, userID); err != nil {
		response.AbortWithStatusError(c, http.StatusInternalServerError, response.ErrInternal, err.Error())
		return
	}

	c.Status(http.StatusOK)
}

func platformAccountUserID(c *gin.Context) (uint, error) {
	if raw := c.Param("user_id"); raw != "" {
		id, err := strconv.ParseUint(raw, 10, 32)
		return uint(id), err
	}
	var req struct {
		UserID uint `json:"user_id" form:"user_id"`
	}
	if err := c.ShouldBind(&req); err != nil {
		return 0, err
	}
	return req.UserID, nil
}