package v1

import (
	"net/http"

	"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"
)

// AgentCapacityHandler handles AgentCapacityPolicy CRUD operations.
// Reference: Chatwoot enterprise/app/controllers/api/v1/agent_capacity_policies_controller.rb
type AgentCapacityHandler struct {
	svc *service.AgentCapacityPolicyService
}

// NewAgentCapacityHandler creates a new AgentCapacityPolicy handler.
func NewAgentCapacityHandler(svc *service.AgentCapacityPolicyService) *AgentCapacityHandler {
	return &AgentCapacityHandler{svc: svc}
}

// List returns all agent capacity policies for an account.
// GET /api/v1/accounts/:account_id/agent_capacity_policies
func (h *AgentCapacityHandler) 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)
	policies, total, err := h.svc.List(c.Request.Context(), accountID, pg.Page, pg.PerPage)
	if err != nil {
		applogger.L().Errorf("List agent capacity policies for account %d: %v", accountID, err)
		handleServiceError(c, err)
		return
	}

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

// Create creates a new agent capacity policy for an account.
// POST /api/v1/accounts/:account_id/agent_capacity_policies
// Request body uses Chatwoot-style wrapper: { "agent_capacity_policy": { "name": "...", ... } }
func (h *AgentCapacityHandler) Create(c *gin.Context) {
	accountID := getAccountID(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusUnauthorized, response.ErrUnauthorized, "account not identified")
		return
	}

	var wrapper struct {
		AgentCapacityPolicy service.CreateAgentCapacityPolicyRequest `json:"agent_capacity_policy"`
	}
	if err := c.ShouldBindJSON(&wrapper); err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrValidation, err.Error())
		return
	}

	policy, err := h.svc.Create(c.Request.Context(), accountID, wrapper.AgentCapacityPolicy)
	if err != nil {
		applogger.L().Errorf("Create agent capacity policy for account %d: %v", accountID, err)
		handleServiceError(c, err)
		return
	}

	response.Created(c, policy)
}

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

	id, err := parseUintParam(c, "id")
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid id")
		return
	}

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

	response.OK(c, policy)
}

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

	id, err := parseUintParam(c, "id")
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid id")
		return
	}

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

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

	response.OK(c, policy)
}

// Delete deletes an agent capacity policy.
// DELETE /api/v1/accounts/:account_id/agent_capacity_policies/:id
func (h *AgentCapacityHandler) Delete(c *gin.Context) {
	accountID := getAccountID(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusUnauthorized, response.ErrUnauthorized, "account not identified")
		return
	}

	id, err := parseUintParam(c, "id")
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid id")
		return
	}

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

	response.NoContent(c)
}

// RegisterAgentCapacityRoutes registers agent capacity policy routes on a gin.RouterGroup.
func RegisterAgentCapacityRoutes(rg *gin.RouterGroup, h *AgentCapacityHandler) {
	policies := rg.Group("/agent_capacity_policies")
	{
		policies.GET("/", h.List)
		policies.POST("/", h.Create)
		policies.GET("/:id", h.Get)
		policies.PUT("/:id", h.Update)
		policies.DELETE("/:id", h.Delete)
	}
}