package main

// The mirror list and its refresher (novox/hq to-be 42 Phase 1). On 2026-10-04 every machine's list
// had been generated once — by a tool no longer installed, or by a hosting provider's installer — and
// never again. The module installs reflector, owns its configuration and enables its weekly timer;
// this reads the list and the refresher's last run, and starts a refresh on demand.

import (
	"strings"
)

// Where the list is and how reflector is told to write it.
const (
	Mirrorlist    = "/etc/pacman.d/mirrorlist"
	ReflectorConf = "/etc/xdg/reflector/reflector.conf"
)

// Mirrors is the mirror list and its refresher.
type Mirrors struct {
	Servers     []string          `json:"servers"`
	Commented   int               `json:"commented_servers"`
	GeneratedBy string            `json:"generated_by,omitempty"`
	When        string            `json:"generated_when,omitempty"`
	Reflector   []string          `json:"reflector_options"`
	Timer       map[string]string `json:"reflector_timer,omitempty"`
	LastRun     map[string]string `json:"reflector_last_run,omitempty"`
	Refreshing  bool              `json:"refresh_started"`
	Note        string            `json:"note,omitempty"`
}

// ParseMirrorlist reads the servers in force, those commented out, and the generator's header.
func ParseMirrorlist(text string) Mirrors {
	m := Mirrors{Servers: []string{}, Reflector: []string{}}
	for _, l := range lines(text) {
		l = strings.TrimSpace(l)
		switch {
		case strings.HasPrefix(l, "Server"):
			if _, v, ok := strings.Cut(l, "="); ok {
				m.Servers = append(m.Servers, strings.TrimSpace(v))
			}
		case strings.HasPrefix(strings.TrimLeft(l, "# "), "Server"):
			m.Commented++
		case strings.Contains(l, "generated by Reflector"):
			m.GeneratedBy = "reflector"
		case strings.HasPrefix(l, "# When:"):
			m.When = strings.TrimSpace(strings.TrimPrefix(l, "# When:"))
		case strings.HasPrefix(l, "## Generated on"):
			m.GeneratedBy, m.When = "the distribution's mirrorlist", strings.TrimSpace(strings.TrimPrefix(l, "## Generated on"))
		}
	}
	return m
}

// MirrorList answers the list, reflector's options, its timer and its last run; refresh starts
// reflector now, without waiting, since ranking mirrors by rate takes longer than a call may.
func (m *Machine) MirrorList(refresh bool) (Mirrors, error) {
	text, err := m.ReadFile(Mirrorlist)
	if err != nil {
		return Mirrors{}, err
	}
	out := ParseMirrorlist(string(text))
	if conf, err := m.ReadFile(ReflectorConf); err == nil {
		for _, l := range lines(string(conf)) {
			if l = strings.TrimSpace(l); !strings.HasPrefix(l, "#") {
				out.Reflector = append(out.Reflector, l)
			}
		}
	}
	if t, err := m.unitProps("reflector.timer", "LoadState", "ActiveState", "UnitFileState", "LastTriggerUSec", "NextElapseUSecRealtime"); err == nil {
		out.Timer = t
	}
	if s, err := m.unitProps("reflector.service", "LoadState", "ActiveState", "Result", "ExecMainExitTimestamp", "ExecMainStatus"); err == nil {
		out.LastRun = s
	}
	if out.Timer["LoadState"] == "not-found" {
		out.Note = "reflector is not installed here; the module installs it"
	}
	if refresh {
		if _, err := m.Root("systemctl", "start", "--no-block", "reflector.service"); err != nil {
			return out, err
		}
		out.Refreshing = true
		out.Note = "reflector is ranking mirrors now; call again in a minute for the new list"
	}
	return out, nil
}