package adminapi

import (
	"encoding/json"
	"fmt"
	"net/http"
	"time"

	"gitea.mynodes.xyz/ilker/llmgw/internal/control/fabrictest"
)

// FabricTestView is a bandwidth test between two nodes.
type FabricTestView struct {
	A      string     `json:"a"`
	B      string     `json:"b"`
	Fabric string     `json:"fabric"`
	OK     bool       `json:"ok"`
	Rails  []RailView `json:"rails"`
	Notes  []string   `json:"notes,omitempty"`
	Took   string     `json:"took"`
}

// RailView is one rail's result.
type RailView struct {
	A        string  `json:"a"`
	B        string  `json:"b"`
	RateGbps int     `json:"rate_gbps"`
	Gbps     float64 `json:"gbps"`
	Verdict  string  `json:"verdict"`
	Detail   string  `json:"detail,omitempty"`
}

// fabricTest measures RDMA bandwidth between two nodes, rail by rail. It
// sends traffic over the fabric for seconds a rail, so it is a POST and only
// ever run when asked.
func (a *API) fabricTest(w http.ResponseWriter, r *http.Request) {
	var body FabricTestRequest
	if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	ask := a.ctl.FabricTester()
	if ask == nil {
		writeError(w, http.StatusNotImplemented, "this control plane cannot reach its nodes' agents")
		return
	}
	inv := a.ctl.Inventory()
	na, okA := inv.Get(body.A)
	nb, okB := inv.Get(body.B)
	if !okA || !okB {
		writeError(w, http.StatusNotFound, fmt.Sprintf("no node %q", map[bool]string{true: body.B, false: body.A}[okA]))
		return
	}
	fabric, rails, notes, err := fabrictest.Plan(na, nb, body.Fabric)
	if err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	start := time.Now()
	rep := fabrictest.Run(r.Context(), ask, na, nb, fabric, rails,
		fabrictest.Options{Seconds: min(max(body.Seconds, 1), 30), Settle: 2 * time.Second})
	v := FabricTestView{A: na.ID, B: nb.ID, Fabric: fabric, OK: rep.OK(), Notes: append(notes, rep.Notes...),
		Took: time.Since(start).Round(time.Second).String()}
	for _, x := range rep.Results {
		v.Rails = append(v.Rails, RailView{x.A, x.B, x.RateGbps, x.Gbps, x.Verdict, x.Detail})
	}
	writeJSON(w, http.StatusOK, v)
}