package main

import (
	"sort"
	"time"
)

// ChannelStatus is one channel as the status says it.
type ChannelStatus struct {
	Name         string `json:"name"`
	CanSend      bool   `json:"can_send"`
	NotReady     string `json:"not_ready,omitempty"`
	LastError    string `json:"last_error,omitempty"`
	LastSent     string `json:"last_sent,omitempty"`
	SentLastHour int    `json:"sent_last_hour"`
	Cap          int    `json:"cap_per_hour"`
	Held         int    `json:"held"` // waiting for their window, the digest or the cap
}

// Status is the holder's whole account of itself.
type Status struct {
	Verdict      string          `json:"verdict"`
	Channels     []ChannelStatus `json:"channels"`
	Open         int             `json:"open"`
	Silenced     int             `json:"silenced"`
	Unsent       []string        `json:"unsent,omitempty"`
	Refused      int             `json:"refused_since_start"`
	Unreadable   int             `json:"unreadable_events_since_start"`
	LastBad      string          `json:"last_unreadable,omitempty"`
	Heard        map[string]int  `json:"events_heard_since_start"`
	LastHeard    string          `json:"last_event_heard,omitempty"`
	Listening    string          `json:"listening"`
	StateRead    string          `json:"state_read,omitempty"`       // when the open conditions were last read from the controller
	StateUnread  string          `json:"state_unreadable,omitempty"` // why they could not be, lately
	History      int             `json:"events_already_in_state"`    // older than the reading: not acted on
	Stale        int             `json:"events_taken_as_state"`      // older than the freshness bound: recorded, never said
	Grace        bool            `json:"in_start_grace,omitempty"`
	StateProblem string          `json:"state_problem,omitempty"`
	TimeZone     string          `json:"time_zone"` // the zone every time in a message is said in
	Rules        []string        `json:"rules"`
}

// Status answers at once from what the holder keeps.
func (h *Holder) Status(listening string) Status {
	now := h.Now()
	var st Status
	for _, ch := range h.channels() {
		cs := ChannelStatus{Name: ch.Name(), Cap: CapPerHour, SentLastHour: h.sentLastHour(ch.Name())}
		if err := ch.Ready(); err != nil {
			cs.NotReady = err.Error()
		} else {
			cs.CanSend = true
		}
		h.mu.Lock()
		cs.LastError = h.chanErr[ch.Name()]
		if t, ok := h.chanOK[ch.Name()]; ok {
			cs.LastSent = t.UTC().Format(time.RFC3339)
		}
		cs.Held = len(h.outbox[ch.Name()])
		h.mu.Unlock()
		if cs.LastError != "" {
			cs.CanSend = false
		}
		st.Channels = append(st.Channels, cs)
	}
	h.mu.Lock()
	for _, r := range h.open {
		if !r.Cleared.IsZero() {
			continue
		}
		st.Open++
		if r.silenced(now) {
			st.Silenced++
		}
		if r.Pending != "" {
			st.Unsent = append(st.Unsent, r.Key+" ("+r.Pending+")")
		}
	}
	st.Refused = len(h.refusals)
	st.Unreadable = h.unreadable
	st.LastBad = h.lastBad
	st.Heard = map[string]int{}
	for k, v := range h.heard {
		st.Heard[k] = v
	}
	if !h.lastHeard.IsZero() {
		st.LastHeard = h.lastHeard.UTC().Format(time.RFC3339)
	}
	st.StateProblem = h.storeErr
	if !h.syncedAt.IsZero() {
		st.StateRead = h.syncedAt.UTC().Format(time.RFC3339)
	}
	st.StateUnread = h.syncErr
	st.History, st.Stale = h.history, h.stale
	st.Grace = h.inGrace(now)
	h.mu.Unlock()
	sort.Strings(st.Unsent)
	st.Listening = listening
	st.TimeZone = h.zone().String()
	st.Rules = []string{
		"a message reads in one glance: the condition's headline as its title, its explanation, and since when in the operator's time zone; no key, id, commit or command — those stay in the controller's conditions and in this holder's history (novox/hq ADR 0253)",
		"a clearance is one line: the condition's resolved line and how long it was open",
		"history is never news: what is open is read from the controller on start, every 10 min and when an old event arrives; an event older than that reading is not acted on, one older than 10 min by its own time is state, never a message",
		"a clearing of something never said says nothing; an urgent condition open and never said is said, all of them in one message",
		"nothing is sent in the first minute after start but that one message",
		"urgent: Telegram and the desktop; warning: the desktop where a session answers, otherwise Telegram",
		"bursts are one message: what arrives within 30 s goes out together, a digest when it is several; urgent goes at once when the channel was quiet for 30 s",
		"the desktop is gentle: warnings at most one message every 15 min",
		"deduplicated by the condition's key; reminded once after 1 h (urgent) or 12 h (warning); cleared by editing the first message",
		"at most 20 messages an hour per channel, a last line of defence: reached, it is said once and the rest held for one digest",
		"refused: anything carrying an address, a path or a secret; channel-refused is sent with the words withheld",
		"silenced conditions send nothing; silence is `conditions silence` through the mesh",
	}
	anyCan := false
	for _, c := range st.Channels {
		anyCan = anyCan || c.CanSend
	}
	switch {
	case !anyCan:
		st.Verdict = "CANNOT SEND: no channel can reach the operator — see channels"
	case len(st.Unsent) > 0:
		st.Verdict = "BEHIND: some messages could not be sent yet and are tried every minute"
	case listening != "listening":
		st.Verdict = "NOT LISTENING: condition events are not reaching this holder — " + listening
	case st.StateProblem != "":
		st.Verdict = "STATE: open messages are held in memory only — " + st.StateProblem
	default:
		st.Verdict = "ok"
		for _, c := range st.Channels {
			if !c.CanSend {
				st.Verdict = "ok on one channel: " + c.Name + " cannot send"
			}
		}
	}
	return st
}

// OpenMessage is one open message as `open` answers it.
type OpenMessage struct {
	Key      string   `json:"key"`
	Severity string   `json:"severity"`
	Summary  string   `json:"summary"`
	Subject  string   `json:"subject,omitempty"`
	Since    string   `json:"since"`
	Origin   string   `json:"origin"`
	SentOn   []string `json:"sent_on,omitempty"`
	Silenced string   `json:"silenced_until,omitempty"`
	Reminded bool     `json:"reminded"`
	Unsent   string   `json:"unsent,omitempty"`
	Held     bool     `json:"held,omitempty"`
	History  bool     `json:"never_said,omitempty"`
	Refused  string   `json:"refused,omitempty"`
	Count    int      `json:"times_opened"`
}

// Open is what is unresolved now, urgent first, oldest first.
func (h *Holder) Open() []OpenMessage {
	now := h.Now()
	h.mu.Lock()
	defer h.mu.Unlock()
	queued := map[string]bool{}
	for _, list := range h.outbox {
		for _, it := range list {
			queued[it.Key] = true
		}
	}
	var out []OpenMessage
	for _, r := range h.open {
		if !r.Cleared.IsZero() {
			continue
		}
		o := OpenMessage{Key: r.Key, Severity: r.Severity, Summary: r.Summary, Subject: r.Subject,
			Since: r.Raised.UTC().Format(time.RFC3339), Origin: r.Origin, Reminded: r.Reminded,
			Unsent: r.Pending, Held: r.Folded || queued[r.Key], History: r.History, Refused: r.Refused, Count: r.Count}
		for ch := range r.Sent {
			o.SentOn = append(o.SentOn, ch)
		}
		sort.Strings(o.SentOn)
		if r.silenced(now) {
			o.Silenced = r.SilencedTill.UTC().Format(time.RFC3339)
		}
		out = append(out, o)
	}
	sort.Slice(out, func(i, j int) bool {
		if out[i].Severity != out[j].Severity {
			return out[i].Severity == Urgent
		}
		return out[i].Since < out[j].Since
	})
	return out
}

// History is what went out, newest first, and the refusals.
func (h *Holder) History(limit int) map[string]any {
	h.mu.Lock()
	defer h.mu.Unlock()
	sends := []Sent{}
	for i := len(h.recent) - 1; i >= 0 && len(sends) < limit; i-- {
		sends = append(sends, h.recent[i])
	}
	refusals := []RefusalNote{}
	for i := len(h.refusals) - 1; i >= 0 && len(refusals) < limit; i-- {
		refusals = append(refusals, h.refusals[i])
	}
	return map[string]any{"sends": sends, "refusals": refusals}
}

// Test sends a test message on one channel or both, through the content rule and the cap.
func (h *Holder) Test(channel, text string) map[string]string {
	h.work.Lock()
	defer h.work.Unlock()
	if text == "" {
		text = "a test from the operator-channel's holder: this channel reaches you"
	}
	out := map[string]string{}
	if refusal, ok := Check(text); !ok {
		out["refused"] = "it carried " + refusal.String() + "; nothing was sent"
		return out
	}
	m := Message{Title: "Test message: " + text, Body: "Nothing is wrong; this was asked for."}
	for _, ch := range h.channels() {
		if channel != "" && channel != "both" && channel != ch.Name() {
			continue
		}
		if err := ch.Ready(); err != nil {
			out[ch.Name()] = "not sent: " + err.Error()
			continue
		}
		if !h.allow(ch.Name()) {
			out[ch.Name()] = "not sent: the channel is at its cap of 20 an hour"
			continue
		}
		if h.sendNow(ch, "messenger.test", "test", m) {
			out[ch.Name()] = "sent"
		} else {
			h.mu.Lock()
			out[ch.Name()] = "failed: " + h.chanErr[ch.Name()]
			h.mu.Unlock()
		}
	}
	return out
}

// Notify takes a message from a module that uses the seat (research 028 Q5, modules as sources):
// the same shape, rule, cap and deduplication as a condition. Its key is put under `notify.` so it
// can never be taken for one of the controller's conditions.
func (h *Holder) Notify(key, severity, summary, subject string, clear bool, plain ...string) (map[string]any, error) {
	if key == "" {
		return nil, errorf("key is required: the same key is the same message")
	}
	if len(key) < 7 || key[:7] != "notify." {
		key = "notify." + key
	}
	h.work.Lock()
	defer h.work.Unlock()
	h.mu.Lock()
	h.init()
	h.mu.Unlock()
	if clear {
		h.cleared(key, false)
		return map[string]any{"key": key, "cleared": true}, nil
	}
	switch severity {
	case Urgent, Warning:
	case "":
		return nil, errorf("severity is required: urgent or warning")
	default:
		return nil, errorf("severity %q is neither urgent nor warning", severity)
	}
	if summary == "" {
		return nil, errorf("summary is required: one line in the mesh's words")
	}
	rec := Record{Key: key, Kind: "notice", Subject: subject, Severity: severity, Summary: summary,
		Origin: "notify", More: "operator-channel.open"}
	// The plain words a module may give (novox/hq ADR 0253): a headline, an explanation, a resolved line.
	for i, w := range plain {
		switch i {
		case 0:
			rec.Headline = w
		case 1:
			rec.Explanation = w
		case 2:
			rec.Resolved = w
		}
	}
	h.raised(rec, false)
	h.mu.Lock()
	r := h.open[key]
	var sent []string
	refused, pending := "", ""
	if r != nil {
		for ch := range r.Sent {
			sent = append(sent, ch)
		}
		refused, pending = r.Refused, r.Pending
	}
	h.mu.Unlock()
	sort.Strings(sent)
	held := h.queued(key)
	return map[string]any{"key": key, "sent_on": sent, "held": held, "refused": refused, "unsent": pending}, nil
}