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"
)

// SummaryReportHandler handles read-only summary report collection endpoints.
// Reference: Chatwoot resources :summary_reports, only: [] do
//
//	collection do
//	  get :agent, :team, :inbox, :label, :channel
//	end
//	end
type SummaryReportHandler struct {
	svc *service.SummaryReportService
}

// NewSummaryReportHandler creates a new SummaryReportHandler.
func NewSummaryReportHandler(svc *service.SummaryReportService) *SummaryReportHandler {
	return &SummaryReportHandler{svc: svc}
}

// Agent returns agent-level summary metrics.
// GET /api/v1/accounts/:account_id/summary_reports/agent
func (h *SummaryReportHandler) Agent(c *gin.Context) {
	accountID, ok := parseAccountID(c)
	if !ok {
		return
	}
	since, until, ok := parseSummaryDateRange(c)
	if !ok {
		return
	}

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

	c.JSON(http.StatusOK, result)
}

// Team returns team-level summary metrics.
// GET /api/v1/accounts/:account_id/summary_reports/team
func (h *SummaryReportHandler) Team(c *gin.Context) {
	accountID, ok := parseAccountID(c)
	if !ok {
		return
	}
	since, until, ok := parseSummaryDateRange(c)
	if !ok {
		return
	}

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

	c.JSON(http.StatusOK, result)
}

// Inbox returns inbox-level summary metrics.
// GET /api/v1/accounts/:account_id/summary_reports/inbox
func (h *SummaryReportHandler) Inbox(c *gin.Context) {
	accountID, ok := parseAccountID(c)
	if !ok {
		return
	}
	since, until, ok := parseSummaryDateRange(c)
	if !ok {
		return
	}

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

	c.JSON(http.StatusOK, result)
}

// Label returns label-level summary metrics.
// GET /api/v1/accounts/:account_id/summary_reports/label
func (h *SummaryReportHandler) Label(c *gin.Context) {
	accountID, ok := parseAccountID(c)
	if !ok {
		return
	}
	since, until, ok := parseSummaryDateRange(c)
	if !ok {
		return
	}

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

	c.JSON(http.StatusOK, result)
}

// Channel returns channel-level summary metrics.
// GET /api/v1/accounts/:account_id/summary_reports/channel
// Reference: Chatwoot summary_reports#channel — enforces 6-month max date range
func (h *SummaryReportHandler) Channel(c *gin.Context) {
	accountID, ok := parseAccountID(c)
	if !ok {
		return
	}
	since, until, ok := parseSummaryDateRange(c)
	if !ok {
		return
	}

	// Chatwoot enforces max 6-month date range for channel summary
	if !until.IsZero() && !since.IsZero() {
		maxRange := since.AddDate(0, 6, 0)
		if until.After(maxRange) {
			response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "date range too long, maximum 6 months")
			return
		}
	}

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

	c.JSON(http.StatusOK, result)
}

// parseSummaryDateRange extracts since/until from query params for summary reports.
func parseSummaryDateRange(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 := parseChatwootReportTime(sinceStr)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid since date format")
		return time.Time{}, time.Time{}, false
	}

	until, err = parseChatwootReportTime(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
}

// RegisterSummaryReportRoutes registers summary report routes on the given router group.
// Routes are account-scoped: GET /summary_reports/agent, /team, /inbox, /label, /channel
func RegisterSummaryReportRoutes(g *gin.RouterGroup, h *SummaryReportHandler) {
	summaryReports := g.Group("/summary_reports")
	{
		summaryReports.GET("/agent", h.Agent)
		summaryReports.GET("/team", h.Team)
		summaryReports.GET("/inbox", h.Inbox)
		summaryReports.GET("/label", h.Label)
		summaryReports.GET("/channel", h.Channel)
	}
}