package v1

import (
	"net/http"
	"time"

	"github.com/gin-gonic/gin"

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

// AnalyticsHandler handles reporting/analytics API endpoints.
// Reference: Chatwoot app/controllers/api/v1/reports_controller.rb
type AnalyticsHandler struct {
	svc *service.AnalyticsService
}

func NewAnalyticsHandler(svc *service.AnalyticsService) *AnalyticsHandler {
	return &AnalyticsHandler{svc: svc}
}

// parseAccountID extracts account_id from URL params.
func parseAccountID(c *gin.Context) (uint, bool) {
	id := getAccountID(c)
	if id == 0 {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid account_id")
		return 0, false
	}
	return id, true
}

// parseDateRange extracts since/unsince from query params.
func parseDateRange(c *gin.Context) (since, until time.Time, ok bool) {
	sinceStr := c.Query("since")
	untilStr := c.Query("until")

	if sinceStr == "" || untilStr == "" {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "since and until query params are required")
		return time.Time{}, time.Time{}, false
	}

	since, err := time.Parse(time.RFC3339, sinceStr)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid since date format")
		return time.Time{}, time.Time{}, false
	}

	until, err = time.Parse(time.RFC3339, untilStr)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid until date format")
		return time.Time{}, time.Time{}, false
	}

	return since, until, true
}

// Summary returns account-level aggregated metrics.
// GET /api/v1/accounts/:account_id/reports/summary
func (h *AnalyticsHandler) Summary(c *gin.Context) {
	accountID, ok := parseAccountID(c)
	if !ok {
		return
	}
	since, until, ok := parseDateRange(c)
	if !ok {
		return
	}

	result, err := h.svc.GetSummary(c.Request.Context(), accountID, since, until)
	if err != nil {
		applogger.L().Errorf("Summary report: %v", err)
		response.AbortWithStatusError(c, http.StatusInternalServerError, response.ErrInternal, "failed to generate summary report")
		return
	}

	response.OK(c, result)
}

// AgentMetrics returns metrics grouped by agent.
// GET /api/v1/accounts/:account_id/reports/agents
func (h *AnalyticsHandler) AgentMetrics(c *gin.Context) {
	accountID, ok := parseAccountID(c)
	if !ok {
		return
	}
	since, until, ok := parseDateRange(c)
	if !ok {
		return
	}

	result, err := h.svc.GetAgentMetrics(c.Request.Context(), accountID, since, until)
	if err != nil {
		applogger.L().Errorf("Agent metrics report: %v", err)
		response.AbortWithStatusError(c, http.StatusInternalServerError, response.ErrInternal, "failed to generate agent metrics")
		return
	}

	response.OK(c, result)
}

// InboxMetrics returns metrics grouped by inbox.
// GET /api/v1/accounts/:account_id/reports/inboxes
func (h *AnalyticsHandler) InboxMetrics(c *gin.Context) {
	accountID, ok := parseAccountID(c)
	if !ok {
		return
	}
	since, until, ok := parseDateRange(c)
	if !ok {
		return
	}

	result, err := h.svc.GetInboxMetrics(c.Request.Context(), accountID, since, until)
	if err != nil {
		applogger.L().Errorf("Inbox metrics report: %v", err)
		response.AbortWithStatusError(c, http.StatusInternalServerError, response.ErrInternal, "failed to generate inbox metrics")
		return
	}

	response.OK(c, result)
}

// LabelMetrics returns metrics grouped by label.
// GET /api/v1/accounts/:account_id/reports/labels
func (h *AnalyticsHandler) LabelMetrics(c *gin.Context) {
	accountID, ok := parseAccountID(c)
	if !ok {
		return
	}
	since, until, ok := parseDateRange(c)
	if !ok {
		return
	}

	result, err := h.svc.GetLabelMetrics(c.Request.Context(), accountID, since, until)
	if err != nil {
		applogger.L().Errorf("Label metrics report: %v", err)
		response.AbortWithStatusError(c, http.StatusInternalServerError, response.ErrInternal, "failed to generate label metrics")
		return
	}

	response.OK(c, result)
}

// TeamMetrics returns metrics grouped by team.
// GET /api/v1/accounts/:account_id/reports/teams
func (h *AnalyticsHandler) TeamMetrics(c *gin.Context) {
	accountID, ok := parseAccountID(c)
	if !ok {
		return
	}
	since, until, ok := parseDateRange(c)
	if !ok {
		return
	}

	result, err := h.svc.GetTeamMetrics(c.Request.Context(), accountID, since, until)
	if err != nil {
		applogger.L().Errorf("Team metrics report: %v", err)
		response.AbortWithStatusError(c, http.StatusInternalServerError, response.ErrInternal, "failed to generate team metrics")
		return
	}

	response.OK(c, result)
}

// ConversationTraffic returns daily conversation traffic time-series.
// GET /api/v1/accounts/:account_id/reports/conversation_traffic
func (h *AnalyticsHandler) ConversationTraffic(c *gin.Context) {
	accountID, ok := parseAccountID(c)
	if !ok {
		return
	}
	since, until, ok := parseDateRange(c)
	if !ok {
		return
	}

	result, err := h.svc.GetConversationTraffic(c.Request.Context(), accountID, since, until)
	if err != nil {
		applogger.L().Errorf("Conversation traffic report: %v", err)
		response.AbortWithStatusError(c, http.StatusInternalServerError, response.ErrInternal, "failed to generate conversation traffic")
		return
	}

	response.OK(c, result)
}
// BotSummary returns bot-level summary metrics.
// GET /api/v1/accounts/:account_id/reports/bot_summary
// Reference: Chatwoot reports#bot_summary
func (h *AnalyticsHandler) BotSummary(c *gin.Context) {
	accountID, ok := parseAccountID(c)
	if !ok {
		return
	}
	since, until, ok := parseDateRange(c)
	if !ok {
		return
	}

	result, err := h.svc.GetBotSummary(c.Request.Context(), accountID, since, until)
	if err != nil {
		applogger.L().Errorf("Bot summary report: %v", err)
		response.AbortWithStatusError(c, http.StatusInternalServerError, response.ErrInternal, "failed to generate bot summary")
		return
	}

	response.OK(c, result)
}

// Conversations returns conversation metrics filtered by type.
// GET /api/v1/accounts/:account_id/reports/conversations
// Reference: Chatwoot reports#conversations — requires params[:type], returns 422 if missing
func (h *AnalyticsHandler) Conversations(c *gin.Context) {
	accountID, ok := parseAccountID(c)
	if !ok {
		return
	}

	reportType := c.Query("type")
	if reportType == "" {
		// Reference: Chatwoot returns head :unprocessable_entity if type is blank
		response.AbortWithStatusError(c, http.StatusUnprocessableEntity, response.ErrBadRequest, "type parameter is required")
		return
	}

	since, until, ok := parseDateRange(c)
	if !ok {
		return
	}

	result, err := h.svc.GetConversationsByType(c.Request.Context(), accountID, reportType, since, until)
	if err != nil {
		applogger.L().Errorf("Conversations report: %v", err)
		response.AbortWithStatusError(c, http.StatusInternalServerError, response.ErrInternal, "failed to generate conversations report")
		return
	}

	response.OK(c, result)
}

// ConversationsSummary returns conversation summary report.
// GET /api/v1/accounts/:account_id/reports/conversations_summary
// Reference: Chatwoot reports#conversations_summary
func (h *AnalyticsHandler) ConversationsSummary(c *gin.Context) {
	accountID, ok := parseAccountID(c)
	if !ok {
		return
	}
	since, until, ok := parseDateRange(c)
	if !ok {
		return
	}

	result, err := h.svc.GetConversationsSummary(c.Request.Context(), accountID, since, until)
	if err != nil {
		applogger.L().Errorf("Conversations summary report: %v", err)
		response.AbortWithStatusError(c, http.StatusInternalServerError, response.ErrInternal, "failed to generate conversations summary")
		return
	}

	response.OK(c, result)
}

// BotMetrics returns bot metrics.
// GET /api/v1/accounts/:account_id/reports/bot_metrics
// Reference: Chatwoot reports#bot_metrics
func (h *AnalyticsHandler) BotMetrics(c *gin.Context) {
	accountID, ok := parseAccountID(c)
	if !ok {
		return
	}
	since, until, ok := parseDateRange(c)
	if !ok {
		return
	}

	result, err := h.svc.GetBotMetrics(c.Request.Context(), accountID, since, until)
	if err != nil {
		applogger.L().Errorf("Bot metrics report: %v", err)
		response.AbortWithStatusError(c, http.StatusInternalServerError, response.ErrInternal, "failed to generate bot metrics")
		return
	}

	response.OK(c, result)
}

// InboxLabelMatrix returns inbox-label matrix data.
// GET /api/v1/accounts/:account_id/reports/inbox_label_matrix
// Reference: Chatwoot reports#inbox_label_matrix
func (h *AnalyticsHandler) InboxLabelMatrix(c *gin.Context) {
	accountID, ok := parseAccountID(c)
	if !ok {
		return
	}

	result, err := h.svc.GetInboxLabelMatrix(c.Request.Context(), accountID)
	if err != nil {
		applogger.L().Errorf("Inbox label matrix report: %v", err)
		response.AbortWithStatusError(c, http.StatusInternalServerError, response.ErrInternal, "failed to generate inbox label matrix")
		return
	}

	response.OK(c, result)
}

// FirstResponseTimeDistribution returns first response time distribution.
// GET /api/v1/accounts/:account_id/reports/first_response_time_distribution
// Reference: Chatwoot reports#first_response_time_distribution
func (h *AnalyticsHandler) FirstResponseTimeDistribution(c *gin.Context) {
	accountID, ok := parseAccountID(c)
	if !ok {
		return
	}
	since, until, ok := parseDateRange(c)
	if !ok {
		return
	}

	result, err := h.svc.GetFirstResponseTimeDistribution(c.Request.Context(), accountID, since, until)
	if err != nil {
		applogger.L().Errorf("First response time distribution report: %v", err)
		response.AbortWithStatusError(c, http.StatusInternalServerError, response.ErrInternal, "failed to generate first response time distribution")
		return
	}

	response.OK(c, result)
}

// OutgoingMessagesCount returns outgoing message count metrics.
// GET /api/v1/accounts/:account_id/reports/outgoing_messages_count
// Reference: Chatwoot reports#outgoing_messages_count
func (h *AnalyticsHandler) OutgoingMessagesCount(c *gin.Context) {
	accountID, ok := parseAccountID(c)
	if !ok {
		return
	}
	since, until, ok := parseDateRange(c)
	if !ok {
		return
	}

	result, err := h.svc.GetOutgoingMessagesCount(c.Request.Context(), accountID, since, until)
	if err != nil {
		applogger.L().Errorf("Outgoing messages count report: %v", err)
		response.AbortWithStatusError(c, http.StatusInternalServerError, response.ErrInternal, "failed to generate outgoing messages count")
		return
	}

	response.OK(c, result)
}