package web

import (
	"context"
	"net/http"
	"strconv"
	"time"

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

// LogSource reads a node's logs. Asked for by type assertion on the cluster
// source, so a source that cannot — a test's, an older one — leaves the page
// saying so rather than every Source having to grow the method.
type LogSource interface {
	NodeLogs(ctx context.Context, node, source string, lines int) adminapi.LogsView
}

type nodeLogsData struct {
	Nav Nav
	adminapi.LogsView
	OnAdminListener bool
	// Base is where this page lives, which differs between the admin
	// listener and the client-facing port.
	Base    string
	Back    string
	Count   int
	Counts  []int
	Follow  bool
	Version string
	Now     string
}

// NodeLogsPage shows the recent lines of one of a node's logs: the agent's
// own, or an engine's output.
//
// What a node did used to be learned by ssh through a jump host and a journal
// only root may read — which, when an engine install fails at two in the
// morning, is several steps between the page that says it failed and the line
// that says why.
func NodeLogsPage(src Source, onAdminListener bool, version string) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		node := r.PathValue("id")
		d := nodeLogsData{
			Nav:             navFrom(r, "cluster"),
			OnAdminListener: onAdminListener,
			Base:            "/admin/nodes/" + node + "/logs",
			Back:            "/admin",
			Counts:          []int{100, 300, 1000, 2000},
			Follow:          r.URL.Query().Get("follow") != "",
			Version:         version,
			Now:             time.Now().UTC().Format(time.RFC3339),
		}
		if onAdminListener {
			d.Base, d.Back = "/nodes/"+node+"/logs", "/"
		}
		d.Count, _ = strconv.Atoi(r.URL.Query().Get("lines"))
		if d.Count <= 0 {
			d.Count = 300
		}
		ls, ok := src.(LogSource)
		if !ok {
			d.LogsView = adminapi.LogsView{Node: node, Error: langOf(r).T("logs.cannot_read")}
		} else {
			// An error the control plane gives back is shown as it came, in
			// English.
			d.LogsView = ls.NodeLogs(r.Context(), node, r.URL.Query().Get("source"), d.Count)
		}
		noStore(w)
		render(w, r, "node_logs", d)
	}
}