package api

import (
	"net/http"

	"github.com/jackc/pgx/v5/pgtype"

	"git.fabledsword.com/bvandeusen/minstrel/internal/db/dbq"
)

// adminQueueView is one queue that waits on a person: how many, and since
// when the oldest of them has waited (null when the queue is empty).
type adminQueueView struct {
	Count int64   `json:"count"`
	Since *string `json:"since"`
}

// adminSummaryView is what the admin rail and the Overview's verdict read
// (#5605): every queue an admin acts on, in one response, so each admin page
// pays one cheap read for its rail.
type adminSummaryView struct {
	Requests   adminQueueView `json:"requests"`
	Reports    adminQueueView `json:"reports"`
	Duplicates adminQueueView `json:"duplicates"`
	Suspect    adminQueueView `json:"suspect"`
	Missing    adminQueueView `json:"missing"`
}

func queueView(count int64, since pgtype.Timestamptz) adminQueueView {
	v := adminQueueView{Count: count}
	if count > 0 && since.Valid {
		s := formatTimestamp(since)
		v.Since = &s
	}
	return v
}

func adminSummaryFrom(row dbq.AdminSummaryRow) adminSummaryView {
	return adminSummaryView{
		Requests:   queueView(row.Requests, row.RequestsSince),
		Reports:    queueView(row.Reports, row.ReportsSince),
		Duplicates: queueView(row.Duplicates, row.DuplicatesSince),
		Suspect:    queueView(row.Suspect, row.SuspectSince),
		Missing:    queueView(row.Missing, row.MissingSince),
	}
}

// handleGetAdminSummary implements GET /api/admin/summary.
func (h *handlers) handleGetAdminSummary(w http.ResponseWriter, r *http.Request) {
	row, err := dbq.New(h.pool).AdminSummary(r.Context())
	if err != nil {
		h.logger.Error("admin: summary", "err", err)
		writeAdminJSONErr(w, http.StatusInternalServerError, "server_error")
		return
	}
	writeJSON(w, http.StatusOK, adminSummaryFrom(row))
}