package api

import (
	"net/http"
	"time"

	"github.com/thepeterstone/claudomator/internal/storage"
)

// parseWindow resolves a ?window= query param to a lookback duration,
// defaulting to def when absent/unrecognized. Mirrors
// handleGetDashboardStats' "24h vs 7d" special-casing, generalized with a
// few friendly aliases plus a time.ParseDuration fallback for anything else
// (e.g. "2h", "90m").
func parseWindow(v string, def time.Duration) time.Duration {
	switch v {
	case "":
		return def
	case "5h":
		return 5 * time.Hour
	case "24h":
		return 24 * time.Hour
	case "7d":
		return 7 * 24 * time.Hour
	default:
		if d, err := time.ParseDuration(v); err == nil && d > 0 {
			return d
		}
		return def
	}
}

// handleGetEscalationFunnel returns the (escalation_rung, agent) aggregate
// that drives the budget dashboard's escalation funnel — the harness's core
// "resolve locally, escalate only when needed" story made visible.
// GET /api/escalation-funnel?window=24h|5h|7d|<Go duration>
//
// Defaults to a 24h window: wider than the budget accountant's 5h rolling
// spend window (which exists to gate live dispatch), since this is a
// historical/observability view, not a live gate — 24h gives a more
// representative sample of rung distribution without requiring the caller
// to know the accountant's configured window.
func (s *Server) handleGetEscalationFunnel(w http.ResponseWriter, r *http.Request) {
	window := parseWindow(r.URL.Query().Get("window"), 24*time.Hour)
	since := time.Now().Add(-window)

	buckets, err := s.store.QueryEscalationFunnel(since)
	if err != nil {
		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": err.Error()})
		return
	}
	if buckets == nil {
		buckets = []storage.EscalationBucket{}
	}
	writeJSON(w, http.StatusOK, buckets)
}

// handleGetSpendTimeseries returns cost-per-provider bucketed over time —
// hourly for windows of a day or less, daily otherwise (mirroring
// QueryDashboardStats' own hourly-throughput/daily-billing split).
// GET /api/spend-timeseries?window=24h|5h|7d|<Go duration>
func (s *Server) handleGetSpendTimeseries(w http.ResponseWriter, r *http.Request) {
	window := parseWindow(r.URL.Query().Get("window"), 24*time.Hour)
	since := time.Now().Add(-window)

	points, err := s.store.QuerySpendTimeseries(since, window <= 26*time.Hour)
	if err != nil {
		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": err.Error()})
		return
	}
	if points == nil {
		points = []storage.SpendPoint{}
	}
	writeJSON(w, http.StatusOK, points)
}