package v1

import (
	"net/http"
	"strconv"

	"github.com/gin-gonic/gin"

	"github.com/gochat/gochat/internal/service"
	applogger "github.com/gochat/gochat/pkg/logger"
	"github.com/gochat/gochat/pkg/pagination"
	"github.com/gochat/gochat/pkg/response"
)

// TeamHandler handles Team CRUD + members.
// Reference: Chatwoot app/controllers/api/v1/teams_controller.rb
type TeamHandler struct {
	svc *service.TeamService
}

// NewTeamHandler creates a new Team handler.
func NewTeamHandler(svc *service.TeamService) *TeamHandler {
	return &TeamHandler{svc: svc}
}

// List returns all teams for an account.
// GET /api/v1/accounts/:account_id/teams
func (h *TeamHandler) List(c *gin.Context) {
	accountID := getAccountID(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusUnauthorized, response.ErrUnauthorized, "account not identified")
		return
	}

	pg := pagination.Parse(c)
	teams, total, err := h.svc.List(c.Request.Context(), accountID, pg.Offset, pg.PerPage)
	if err != nil {
		applogger.L().Errorf("List teams for account %d: %v", accountID, err)
		handleServiceError(c, err)
		return
	}

	response.OKWithMeta(c, teams, pg.Page, pg.PerPage, total)
}

// Get returns a single team by ID.
// GET /api/v1/accounts/:account_id/teams/:id
func (h *TeamHandler) Get(c *gin.Context) {
	accountID := getAccountID(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusUnauthorized, response.ErrUnauthorized, "account not identified")
		return
	}

	id, err := strconv.ParseUint(c.Param("id"), 10, 32)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid team ID")
		return
	}

	team, svcErr := h.svc.Get(c.Request.Context(), uint(id), accountID)
	if svcErr != nil {
		applogger.L().Errorf("Get team %d for account %d: %v", id, accountID, svcErr)
		handleServiceError(c, svcErr)
		return
	}

	response.OK(c, team)
}

// Create creates a new team within an account.
// POST /api/v1/accounts/:account_id/teams
func (h *TeamHandler) Create(c *gin.Context) {
	accountID := getAccountID(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusUnauthorized, response.ErrUnauthorized, "account not identified")
		return
	}

	// Chatwoot: params.require(:team) → request body must be {"team": {...}}
	var wrapper struct {
		Team service.CreateTeamRequest `json:"team"`
	}
	if err := c.ShouldBindJSON(&wrapper); err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, err.Error())
		return
	}
	req := wrapper.Team

	team, svcErr := h.svc.Create(c.Request.Context(), accountID, req)
	if svcErr != nil {
		applogger.L().Errorf("Create team for account %d: %v", accountID, svcErr)
		handleServiceError(c, svcErr)
		return
	}

	response.Created(c, team)
}

// Update updates an existing team.
// PUT /api/v1/accounts/:account_id/teams/:id
func (h *TeamHandler) Update(c *gin.Context) {
	accountID := getAccountID(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusUnauthorized, response.ErrUnauthorized, "account not identified")
		return
	}

	id, err := strconv.ParseUint(c.Param("id"), 10, 32)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid team ID")
		return
	}

	// Chatwoot: params.require(:team) → request body must be {"team": {...}}
	var wrapper struct {
		Team service.UpdateTeamRequest `json:"team"`
	}
	if err := c.ShouldBindJSON(&wrapper); err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, err.Error())
		return
	}
	req := wrapper.Team

	team, svcErr := h.svc.Update(c.Request.Context(), uint(id), accountID, req)
	if svcErr != nil {
		applogger.L().Errorf("Update team %d for account %d: %v", id, accountID, svcErr)
		handleServiceError(c, svcErr)
		return
	}

	response.OK(c, team)
}

// Delete soft-deletes a team.
// DELETE /api/v1/accounts/:account_id/teams/:id
func (h *TeamHandler) Delete(c *gin.Context) {
	accountID := getAccountID(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusUnauthorized, response.ErrUnauthorized, "account not identified")
		return
	}

	id, err := strconv.ParseUint(c.Param("id"), 10, 32)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid team ID")
		return
	}

	if svcErr := h.svc.Delete(c.Request.Context(), uint(id), accountID); svcErr != nil {
		applogger.L().Errorf("Delete team %d for account %d: %v", id, accountID, svcErr)
		handleServiceError(c, svcErr)
		return
	}

	response.NoContent(c)
}

// AddMembers adds users to a team.
// POST /api/v1/accounts/:account_id/teams/:id/members
func (h *TeamHandler) AddMembers(c *gin.Context) {
	accountID := getAccountID(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusUnauthorized, response.ErrUnauthorized, "account not identified")
		return
	}

	id, err := strconv.ParseUint(c.Param("id"), 10, 32)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid team ID")
		return
	}

	var req service.TeamMemberRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, err.Error())
		return
	}

	members, svcErr := h.svc.AddMembers(c.Request.Context(), uint(id), accountID, req.UserIDs)
	if svcErr != nil {
		applogger.L().Errorf("Add members to team %d for account %d: %v", id, accountID, svcErr)
		handleServiceError(c, svcErr)
		return
	}

	response.OK(c, members)
}

// RemoveMembers removes a user from a team.
// DELETE /api/v1/accounts/:account_id/teams/:id/members/:user_id
func (h *TeamHandler) RemoveMembers(c *gin.Context) {
	accountID := getAccountID(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusUnauthorized, response.ErrUnauthorized, "account not identified")
		return
	}

	id, err := strconv.ParseUint(c.Param("id"), 10, 32)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid team ID")
		return
	}

	userID, err := strconv.ParseUint(c.Param("user_id"), 10, 32)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid user ID")
		return
	}

	if svcErr := h.svc.RemoveMember(c.Request.Context(), uint(id), uint(userID), accountID); svcErr != nil {
		applogger.L().Errorf("Remove member %d from team %d for account %d: %v", userID, id, accountID, svcErr)
		handleServiceError(c, svcErr)
		return
	}

	response.NoContent(c)
}

// ListMembers retrieves all members of a team.
// GET /api/v1/accounts/:account_id/teams/:id/members
func (h *TeamHandler) ListMembers(c *gin.Context) {
	accountID := getAccountID(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusUnauthorized, response.ErrUnauthorized, "account not identified")
		return
	}

	id, err := strconv.ParseUint(c.Param("id"), 10, 32)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid team ID")
		return
	}

	members, svcErr := h.svc.ListMembers(c.Request.Context(), uint(id), accountID)
	if svcErr != nil {
		applogger.L().Errorf("List members for team %d for account %d: %v", id, accountID, svcErr)
		handleServiceError(c, svcErr)
		return
	}

	response.OK(c, members)
}

// UpdateMembers adds/removes members to match the provided user_ids list.
// PATCH /api/v1/accounts/:account_id/teams/:team_id/team_members
// Reference: Chatwoot team_members#update — calculates add/remove diffs from user_ids
func (h *TeamHandler) UpdateMembers(c *gin.Context) {
	accountID := getAccountID(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusUnauthorized, response.ErrUnauthorized, "account not identified")
		return
	}

	teamID, err := strconv.ParseUint(c.Param("team_id"), 10, 32)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid team ID")
		return
	}

	var req service.TeamMemberRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, err.Error())
		return
	}

	members, svcErr := h.svc.UpdateMembers(c.Request.Context(), uint(teamID), accountID, req.UserIDs)
	if svcErr != nil {
		applogger.L().Errorf("Update members for team %d for account %d: %v", teamID, accountID, svcErr)
		handleServiceError(c, svcErr)
		return
	}

	response.OK(c, members)
}