package v1

import (
	"net/http"
	"strconv"

	"github.com/gin-gonic/gin"

	"github.com/gochat/gochat/internal/model"
	"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
	}

	_ = total
	c.JSON(http.StatusOK, serializeTeams(c, h.svc, teams))
}

// 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 := parseTeamIDParam(c)
	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
	}

	c.JSON(http.StatusOK, serializeTeamForAccount(c, h.svc, 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
	}

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

	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
	}

	c.JSON(http.StatusOK, serializeTeamForAccount(c, h.svc, 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 := parseTeamIDParam(c)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid team ID")
		return
	}

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

	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
	}

	c.JSON(http.StatusOK, serializeTeamForAccount(c, h.svc, 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 := parseTeamIDParam(c)
	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
	}

	c.Status(http.StatusOK)
}

// 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 := parseTeamIDParam(c)
	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
	}

	_, 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
	}
	members, svcErr := h.svc.ListMembers(c.Request.Context(), uint(id), accountID)
	if svcErr != nil {
		handleServiceError(c, svcErr)
		return
	}

	c.JSON(http.StatusOK, serializeTeamMemberAgents(accountID, 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 := parseTeamIDParam(c)
	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
	}

	c.Status(http.StatusOK)
}

// 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 := parseTeamIDParam(c)
	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
	}

	c.JSON(http.StatusOK, serializeTeamMemberAgents(accountID, 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 := parseTeamIDParam(c)
	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
	}

	c.JSON(http.StatusOK, serializeTeamMemberAgents(accountID, members))
}

func parseTeamIDParam(c *gin.Context) (uint64, error) {
	value := c.Param("team_id")
	if value == "" {
		value = c.Param("id")
	}
	return strconv.ParseUint(value, 10, 32)
}

func serializeTeams(c *gin.Context, svc *service.TeamService, teams []model.Team) []map[string]any {
	payload := make([]map[string]any, 0, len(teams))
	for i := range teams {
		payload = append(payload, serializeTeamForAccount(c, svc, &teams[i]))
	}
	return payload
}

func serializeTeamForAccount(c *gin.Context, svc *service.TeamService, team *model.Team) map[string]any {
	if team == nil {
		return map[string]any{}
	}
	payload := map[string]any{
		"id":                team.ID,
		"name":              team.Name,
		"description":       team.Description,
		"allow_auto_assign": team.AllowAutoAssignment,
		"account_id":        team.AccountID,
		"is_member":         false,
	}
	userID := getUserID(c)
	if userID != 0 && svc != nil && svc.DB() != nil {
		var count int64
		svc.DB().WithContext(c.Request.Context()).Model(&model.TeamMember{}).Where("team_id = ? AND user_id = ?", team.ID, userID).Count(&count)
		payload["is_member"] = count > 0
	}
	return payload
}

func serializeTeamMemberAgents(accountID uint, members []model.TeamMember) []map[string]any {
	payload := make([]map[string]any, 0, len(members))
	for i := range members {
		member := members[i]
		payload = append(payload, serializeAgentUser(&member.User, accountID, "", member.AvailabilityStatus, false, 0))
	}
	return payload
}