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"
)

// CampaignHandler handles Campaign CRUD + trigger actions.
// Reference: Chatwoot app/controllers/api/v1/campaigns_controller.rb
type CampaignHandler struct {
	svc *service.CampaignService
}

// NewCampaignHandler creates a new Campaign handler.
func NewCampaignHandler(svc *service.CampaignService) *CampaignHandler {
	return &CampaignHandler{svc: svc}
}

// List returns all campaigns for an account.
// GET /api/v1/accounts/:id/campaigns
func (h *CampaignHandler) 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)
	campaigns, total, err := h.svc.List(c.Request.Context(), accountID, pg.Offset, pg.PerPage)
	if err != nil {
		applogger.L().Errorf("List campaigns for account %d: %v", accountID, err)
		handleServiceError(c, err)
		return
	}

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

// Get returns a single campaign by ID.
// GET /api/v1/accounts/:id/campaigns/:campaign_id
func (h *CampaignHandler) 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("campaign_id"), 10, 32)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid campaign ID")
		return
	}

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

	response.OK(c, campaign)
}

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

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

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

	response.Created(c, campaign)
}

// Update updates an existing campaign.
// PUT /api/v1/accounts/:id/campaigns/:campaign_id
func (h *CampaignHandler) 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("campaign_id"), 10, 32)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid campaign ID")
		return
	}

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

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

	response.OK(c, campaign)
}

// Delete soft-deletes a campaign.
// DELETE /api/v1/accounts/:id/campaigns/:campaign_id
func (h *CampaignHandler) 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("campaign_id"), 10, 32)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid campaign ID")
		return
	}

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

	response.NoContent(c)
}

// Start triggers a campaign execution.
// POST /api/v1/accounts/:id/campaigns/:campaign_id/start
func (h *CampaignHandler) Start(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("campaign_id"), 10, 32)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid campaign ID")
		return
	}

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

	response.OK(c, gin.H{"message": "campaign triggered successfully"})
}

// Stop marks a campaign as completed.
// POST /api/v1/accounts/:id/campaigns/:campaign_id/stop
func (h *CampaignHandler) Stop(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("campaign_id"), 10, 32)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid campaign ID")
		return
	}

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

	response.OK(c, gin.H{"message": "campaign stopped successfully"})
}