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/response"
)

// AssignmentPolicyHandler handles AssignmentPolicy CRUD + auto-assignment actions.
// Reference: Chatwoot app/controllers/api/v1/assignment_policies_controller.rb
type AssignmentPolicyHandler struct {
	svc *service.AssignmentPolicyService
}

// ListAccountPolicies returns all assignment policies for the account.
// GET /api/v1/accounts/:id/assignment_policies
func (h *AssignmentPolicyHandler) ListAccountPolicies(c *gin.Context) {
	accountID := getAccountID(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusUnauthorized, response.ErrUnauthorized, "account not identified")
		return
	}

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

	c.JSON(http.StatusOK, policies)
}

// NewAssignmentPolicyHandler creates a new AssignmentPolicy handler.
func NewAssignmentPolicyHandler(svc *service.AssignmentPolicyService) *AssignmentPolicyHandler {
	return &AssignmentPolicyHandler{svc: svc}
}

// GetAccountPolicy returns the account-level assignment policy.
// GET /api/v1/accounts/:id/assignment_policy
func (h *AssignmentPolicyHandler) GetAccountPolicy(c *gin.Context) {
	accountID := getAccountID(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusUnauthorized, response.ErrUnauthorized, "account not identified")
		return
	}

	var policyID uint
	if raw := c.Param("policy_id"); raw != "" {
		id, err := strconv.ParseUint(raw, 10, 32)
		if err != nil {
			response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid policy ID")
			return
		}
		policyID = uint(id)
	}

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

	payload, svcErr := h.svc.SerializePolicy(c.Request.Context(), policy)
	if svcErr != nil {
		handleServiceError(c, svcErr)
		return
	}
	c.JSON(http.StatusOK, payload)
}

// CreateAccountPolicy creates the account-level assignment policy.
// POST /api/v1/accounts/:id/assignment_policy
func (h *AssignmentPolicyHandler) CreateAccountPolicy(c *gin.Context) {
	accountID := getAccountID(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusUnauthorized, response.ErrUnauthorized, "account not identified")
		return
	}

	req, err := bindAssignmentPolicyCreate(c)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, err.Error())
		return
	}

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

	payload, svcErr := h.svc.SerializePolicy(c.Request.Context(), policy)
	if svcErr != nil {
		handleServiceError(c, svcErr)
		return
	}
	c.JSON(http.StatusOK, payload)
}

// UpdateAccountPolicy updates the account-level assignment policy.
// PUT /api/v1/accounts/:id/assignment_policy
func (h *AssignmentPolicyHandler) UpdateAccountPolicy(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("policy_id"), 10, 32)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid policy ID")
		return
	}

	req, err := bindAssignmentPolicyUpdate(c)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, err.Error())
		return
	}

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

	payload, svcErr := h.svc.SerializePolicy(c.Request.Context(), policy)
	if svcErr != nil {
		handleServiceError(c, svcErr)
		return
	}
	c.JSON(http.StatusOK, payload)
}

// DeleteAccountPolicy deletes the account-level assignment policy.
// DELETE /api/v1/accounts/:id/assignment_policy/:policy_id
func (h *AssignmentPolicyHandler) DeleteAccountPolicy(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("policy_id"), 10, 32)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid policy ID")
		return
	}

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

	c.Status(http.StatusOK)
}

// GetInboxPolicy returns the inbox-level assignment policy override.
// GET /api/v1/accounts/:id/inboxes/:inbox_id/assignment_policy
func (h *AssignmentPolicyHandler) GetInboxPolicy(c *gin.Context) {
	accountID := getAccountID(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusUnauthorized, response.ErrUnauthorized, "account not identified")
		return
	}

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

	policy, svcErr := h.svc.GetInboxPolicy(c.Request.Context(), accountID, uint(inboxID))
	if svcErr != nil {
		applogger.L().Errorf("Get inbox assignment policy for inbox %d: %v", inboxID, svcErr)
		handleServiceError(c, svcErr)
		return
	}

	payload, svcErr := h.svc.SerializePolicy(c.Request.Context(), policy)
	if svcErr != nil {
		handleServiceError(c, svcErr)
		return
	}
	c.JSON(http.StatusOK, payload)
}

// ListPolicyInboxes returns Chatwoot `{ inboxes: [...] }` payload for a policy.
// GET /api/v1/accounts/:id/assignment_policies/:policy_id/inboxes
func (h *AssignmentPolicyHandler) ListPolicyInboxes(c *gin.Context) {
	accountID := getAccountID(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusUnauthorized, response.ErrUnauthorized, "account not identified")
		return
	}
	policyID, err := strconv.ParseUint(c.Param("policy_id"), 10, 32)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid policy ID")
		return
	}

	inboxes, svcErr := h.svc.ListPolicyInboxes(c.Request.Context(), accountID, uint(policyID))
	if svcErr != nil {
		handleServiceError(c, svcErr)
		return
	}
	c.JSON(http.StatusOK, gin.H{"inboxes": inboxes})
}

// AddPolicyInbox associates an inbox with a policy through the nested policy route.
// POST /api/v1/accounts/:id/assignment_policies/:policy_id/inboxes
func (h *AssignmentPolicyHandler) AddPolicyInbox(c *gin.Context) {
	accountID := getAccountID(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusUnauthorized, response.ErrUnauthorized, "account not identified")
		return
	}
	policyID, err := strconv.ParseUint(c.Param("policy_id"), 10, 32)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid policy ID")
		return
	}
	var req service.CreateInboxPolicyRequest
	if err := c.ShouldBindJSON(&req); err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, err.Error())
		return
	}
	req.AssignmentPolicyID = uint(policyID)
	policy, svcErr := h.svc.CreateInboxPolicy(c.Request.Context(), accountID, req)
	if svcErr != nil {
		handleServiceError(c, svcErr)
		return
	}
	payload, svcErr := h.svc.SerializePolicy(c.Request.Context(), policy)
	if svcErr != nil {
		handleServiceError(c, svcErr)
		return
	}
	c.JSON(http.StatusOK, payload)
}

// RemovePolicyInbox removes the current policy association from an inbox.
// DELETE /api/v1/accounts/:id/assignment_policies/:policy_id/inboxes/:inbox_id
func (h *AssignmentPolicyHandler) RemovePolicyInbox(c *gin.Context) {
	accountID := getAccountID(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusUnauthorized, response.ErrUnauthorized, "account not identified")
		return
	}
	inboxID, err := strconv.ParseUint(c.Param("inbox_id"), 10, 32)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid inbox ID")
		return
	}
	if svcErr := h.svc.DeleteInboxPolicy(c.Request.Context(), uint(inboxID), accountID); svcErr != nil {
		handleServiceError(c, svcErr)
		return
	}
	c.Status(http.StatusOK)
}

// CreateInboxPolicy creates an inbox-level assignment policy override.
// POST /api/v1/accounts/:id/inboxes/:inbox_id/assignment_policy
func (h *AssignmentPolicyHandler) CreateInboxPolicy(c *gin.Context) {
	accountID := getAccountID(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusUnauthorized, response.ErrUnauthorized, "account not identified")
		return
	}

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

	var req service.CreateInboxPolicyRequest
	req.InboxID = uint(inboxID) // Set from URL param
	if err := bindAssignmentPolicyBody(c, &req); err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, err.Error())
		return
	}

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

	payload, svcErr := h.svc.SerializePolicy(c.Request.Context(), policy)
	if svcErr != nil {
		handleServiceError(c, svcErr)
		return
	}
	c.JSON(http.StatusOK, payload)
}

// UpdateInboxPolicy updates an inbox-level assignment policy override.
// PUT /api/v1/accounts/:id/inboxes/:inbox_id/assignment_policy/:policy_id
func (h *AssignmentPolicyHandler) UpdateInboxPolicy(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("policy_id"), 10, 32)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid policy ID")
		return
	}

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

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

	response.OK(c, policy)
}

// DeleteInboxPolicy deletes an inbox-level assignment policy override.
// DELETE /api/v1/accounts/:id/inboxes/:inbox_id/assignment_policy/:policy_id
func (h *AssignmentPolicyHandler) DeleteInboxPolicy(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("policy_id"), 10, 32)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid policy ID")
		return
	}

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

	c.Status(http.StatusOK)
}

// DeleteCurrentInboxPolicy removes the policy association for the URL inbox.
// DELETE /api/v1/accounts/:id/inboxes/:inbox_id/assignment_policy
func (h *AssignmentPolicyHandler) DeleteCurrentInboxPolicy(c *gin.Context) {
	accountID := getAccountID(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusUnauthorized, response.ErrUnauthorized, "account not identified")
		return
	}
	inboxID, err := strconv.ParseUint(c.Param("inbox_id"), 10, 32)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid inbox ID")
		return
	}
	if svcErr := h.svc.DeleteInboxPolicy(c.Request.Context(), uint(inboxID), accountID); svcErr != nil {
		handleServiceError(c, svcErr)
		return
	}
	c.Status(http.StatusOK)
}

func bindAssignmentPolicyCreate(c *gin.Context) (*service.CreatePolicyRequest, error) {
	var req service.CreatePolicyRequest
	if err := bindChatwootPayload(c, "assignment_policy", &req); err != nil {
		return nil, err
	}
	return &req, nil
}

func bindAssignmentPolicyUpdate(c *gin.Context) (*service.UpdatePolicyRequest, error) {
	var req service.UpdatePolicyRequest
	if err := bindChatwootPayload(c, "assignment_policy", &req); err != nil {
		return nil, err
	}
	return &req, nil
}

func bindAssignmentPolicyBody(c *gin.Context, req *service.CreateInboxPolicyRequest) error {
	var body struct {
		AssignmentPolicyID uint `json:"assignment_policy_id"`
	}
	if err := c.ShouldBindJSON(&body); err != nil {
		return err
	}
	req.AssignmentPolicyID = body.AssignmentPolicyID
	return nil
}