package main

import (
	"context"
	"encoding/json"
	"errors"
	"os"
	"path/filepath"
	"regexp"
	"slices"
	"sort"
	"strings"
	"testing"
	"time"

	oc "git.novox.be/novox/mesh-contracts/operator-and-conversation/go/seats/operatorchannel"
	stdio "git.novox.be/novox/mesh-sdk/go"

	"claude-licence-manager/internal/licences"
)

// runtime is a fixture of the runtime's bus-state and log calls (design 39 parts §3): it answers every read from what
// a test seeds, and fails the test on any write or append the tools bundle makes.
type runtime struct {
	t      *testing.T
	states map[string]map[string]json.RawMessage
	logs   map[string][]stdio.LogEntry
}

func newRuntime(t *testing.T) *runtime {
	rt := &runtime{t: t, states: map[string]map[string]json.RawMessage{}, logs: map[string][]stdio.LogEntry{}}
	for _, s := range licences.States {
		rt.states[s] = map[string]json.RawMessage{}
	}
	for _, l := range licences.Logs {
		rt.logs[l] = nil
	}
	return rt
}

// seedState and seedLog keep what the manager wrote before the tools were asked.
func (rt *runtime) seedState(state, key string, v any) {
	raw, _ := json.Marshal(v)
	rt.states[state][key] = raw
}

func (rt *runtime) seedLog(log, key string, v any) {
	raw, _ := json.Marshal(v)
	rt.logs[log] = append(rt.logs[log], stdio.LogEntry{Sequence: uint64(len(rt.logs[log]) + 1), Key: key, Value: raw})
}

func (rt *runtime) reader() *Reader {
	r := &Reader{States: map[string]licences.State{}, Logs: map[string]licences.Log{}}
	for s := range rt.states {
		r.States[s] = keptState{rt, s}
	}
	for l := range rt.logs {
		r.Logs[l] = keptLog{rt, l}
	}
	return r
}

type keptState struct {
	rt   *runtime
	name string
}

func (s keptState) wrote(how, key string) error {
	s.rt.t.Errorf("the tools bundle %s %s.%s: it writes nothing", how, s.name, key)
	return errors.New("refused: the tools bundle writes nothing")
}

func (s keptState) Get(key string) (*stdio.StateEntry, error) {
	v, ok := s.rt.states[s.name][key]
	if !ok {
		return nil, nil
	}
	return &stdio.StateEntry{Key: key, Value: v, Revision: 1}, nil
}
func (s keptState) Put(key string, _ any) (uint64, error) { return 0, s.wrote("put", key) }
func (s keptState) PutTTL(key string, _ any, _ time.Duration) (uint64, error) {
	return 0, s.wrote("put", key)
}
func (s keptState) Create(key string, _ any) (uint64, error) { return 0, s.wrote("created", key) }
func (s keptState) CreateTTL(key string, _ any, _ time.Duration) (uint64, error) {
	return 0, s.wrote("created", key)
}
func (s keptState) Delete(key string) error { return s.wrote("deleted", key) }
func (s keptState) Keys() ([]string, error) {
	keys := []string{}
	for k := range s.rt.states[s.name] {
		keys = append(keys, k)
	}
	sort.Strings(keys)
	return keys, nil
}
func (s keptState) History(key string) ([]stdio.StateRevision, error) { return nil, nil }

type keptLog struct {
	rt   *runtime
	name string
}

func (l keptLog) Append(key string, _ any) (uint64, error) {
	l.rt.t.Errorf("the tools bundle appended to %s.%s: it writes nothing", l.name, key)
	return 0, errors.New("refused: the tools bundle writes nothing")
}

func (l keptLog) Read(from uint64, keys string, _ int) (*stdio.LogPage, error) {
	page := &stdio.LogPage{Last: uint64(len(l.rt.logs[l.name]))}
	for _, e := range l.rt.logs[l.name] {
		if e.Sequence >= from && (keys == "" || e.Key == keys) {
			page.Entries = append(page.Entries, e)
		}
	}
	return page, nil
}

func (l keptLog) Last(key string) (*stdio.LogEntry, error) {
	var last *stdio.LogEntry
	for _, e := range l.rt.logs[l.name] {
		if e.Key == key {
			last = &e
		}
	}
	return last, nil
}

func (l keptLog) Info() (*stdio.LogInfo, error) {
	n := uint64(len(l.rt.logs[l.name]))
	return &stdio.LogInfo{Entries: n, Last: n, First: min(n, 1), MaxBytes: 64 << 20}, nil
}

func (l keptLog) Newest(string) ([]stdio.LogEntry, error) {
	by := map[string]stdio.LogEntry{}
	for _, e := range l.rt.logs[l.name] {
		by[e.Key] = e
	}
	out := []stdio.LogEntry{}
	for _, e := range by {
		out = append(out, e)
	}
	return out, nil
}

// run is one tool's answer as JSON, decoded into a generic form.
func run(t *testing.T, r *Reader, name string, args map[string]any) any {
	t.Helper()
	for _, tool := range r.Tools() {
		if tool.Name != name {
			continue
		}
		got, err := tool.Run(args)
		if err != nil {
			t.Fatalf("%s %v answered %v", name, args, err)
		}
		raw, _ := json.Marshal(got)
		var v any
		_ = json.Unmarshal(raw, &v)
		return v
	}
	t.Fatalf("the tools bundle registers no %s", name)
	return nil
}

// design 39 parts §3, §4: the tools bundle registers exactly the four reading tools; its code emits nothing,
// subscribes to no event, asks no heartbeat, calls neither the vendor nor the vault, and asks nothing but mesh-config.
func TestTheToolsBundleRegistersTheFourReadingToolsAndActsOnNothing(t *testing.T) {
	var names []string
	for _, tool := range newRuntime(t).reader().Tools() {
		names = append(names, tool.Name)
	}
	sort.Strings(names)
	if want := []string{"licences_conditions", "licences_kept", "licences_settings", "licences_switches"}; !slices.Equal(names, want) {
		t.Fatalf("the tools bundle registers %v, not %v", names, want)
	}
	files, _ := filepath.Glob("*.go")
	acts := regexp.MustCompile(`stdio\.(Emit|Subscribe|SeatPublish|Publish|Heartbeat|Watch)\b|\.(Put|PutTTL|Create|CreateTTL|Delete|Append)\(|os\.(WriteFile|Create|OpenFile)|http\.`)
	asked := regexp.MustCompile(`stdio\.Ask\("([^"]+)"`)
	for _, f := range files {
		if strings.HasSuffix(f, "_test.go") {
			continue
		}
		src, err := os.ReadFile(f)
		if err != nil {
			t.Fatal(err)
		}
		for _, m := range acts.FindAllString(string(src), -1) {
			t.Errorf("%s calls %s: the tools bundle acts on nothing", f, m)
		}
		for _, m := range asked.FindAllStringSubmatch(string(src), -1) {
			if m[1] != "seat:mesh-config.config" {
				t.Errorf("%s asks %s: the tools bundle asks only mesh-config", f, m[1])
			}
		}
	}
}

// design 39 bus-and-switch §37/AC1, design 39 parts §3: a switch by usage and one by a person are answered, newest
// first, with their causes, a switch by usage with the reading that moved them; licence and consumer narrow the
// answer; nothing is written.
func TestSwitchesAnswersBothCauses(t *testing.T) {
	rt := newRuntime(t)
	rt.seedLog(licences.EntryAudit, "switched", map[string]any{"at": "2026-11-12T10:00:00Z", "from": "a", "to": "b",
		"consumers": []string{"ace", "g14"}, "by": "usage", "why": "a at 99 %", "window": "weekly", "pct": 99,
		"resetsAt": "2026-11-14T09:00:00Z", "room": 60})
	rt.seedLog(licences.EntryAudit, "bound", map[string]any{"at": "2026-11-12T10:00:30Z", "consumer": "ace"})
	rt.seedLog(licences.EntryAudit, "switched", map[string]any{"at": "2026-11-12T10:01:00Z", "from": "b", "to": "c",
		"consumers": []string{"ace"}, "by": "a person", "why": "the switch verb"})
	r := rt.reader()
	got := run(t, r, "licences_switches", nil).([]any)
	if len(got) != 2 {
		t.Fatalf("switches %v", got)
	}
	person, usage := got[0].(map[string]any), got[1].(map[string]any)
	if person["by"] != "a person" || person["why"] != "the switch verb" || person["to"] != "c" || person["reading"] != nil ||
		usage["by"] != "usage" || usage["reading"].(map[string]any)["window"] != "weekly" || usage["from"] != "a" {
		t.Fatalf("switches %v", got)
	}
	if got := run(t, r, "licences_switches", map[string]any{"licence": "c"}).([]any); len(got) != 1 {
		t.Fatalf("of c %v", got)
	}
	if got := run(t, r, "licences_switches", map[string]any{"consumer": "g14"}).([]any); len(got) != 1 ||
		got[0].(map[string]any)["by"] != "usage" {
		t.Fatalf("of g14 %v", got)
	}
	if got := run(t, r, "licences_switches", map[string]any{"since": "2026-11-12T10:00:30Z"}).([]any); len(got) != 1 {
		t.Fatalf("since %v", got)
	}
}

// design 39 bus-and-switch §37, §12: a switch carried over from the old table keeps the old field names (consumer,
// licence) and is answered with `to` and `consumers`, and found by them.
func TestSwitchesAnswersCarriedEntries(t *testing.T) {
	rt := newRuntime(t)
	rt.seedLog(licences.EntryAudit, "switched", map[string]any{"at": "2026-11-11T21:10:33Z", "consumer": "n1",
		"licence": "d@example.org", "from": "c@example.org", "by": "a@example.org"})
	r := rt.reader()
	for _, args := range []map[string]any{nil, {"consumer": "n1"}, {"licence": "d@example.org"}} {
		got := run(t, r, "licences_switches", args).([]any)
		if len(got) != 1 {
			t.Fatalf("%v: %v", args, got)
		}
		e := got[0].(map[string]any)
		if e["to"] != "d@example.org" || e["from"] != "c@example.org" || e["by"] != "a@example.org" ||
			len(e["consumers"].([]any)) != 1 || e["consumers"].([]any)[0] != "n1" {
			t.Fatalf("%v: %v", args, e)
		}
	}
}

// design 39 bus-and-switch §40/AC1, B18, design 39 parts §3: a value set at node level is answered with its level, the
// rest with the default, each with its value and default, and an invalid one saying why, read from the settings file;
// mesh-config not answering is an error, never the default.
func TestSettingsAnswersTheLevel(t *testing.T) {
	r := newRuntime(t).reader()
	r.SettingsFile = filepath.Join(t.TempDir(), "settings.json")
	if err := os.WriteFile(r.SettingsFile, []byte(`{"switch_at_pct": 80, "warn_at_pct": 85, "usage_minutes": 900}`), 0o600); err != nil {
		t.Fatal(err)
	}
	r.ConfigLevels = func(context.Context) (map[string]string, error) {
		return map[string]string{"switch_at_pct": "node", "warn_at_pct": "mesh", "cadence_minutes": "default"}, nil
	}
	by := map[string]map[string]any{}
	for _, s := range run(t, r, "licences_settings", nil).([]any) {
		f := s.(map[string]any)
		by[f["setting"].(string)] = f
	}
	str := func(v any) string { s, _ := v.(string); return s }
	if len(by) != len(licences.Defaults.Values()) || by["switch_at_pct"]["level"] != "node" ||
		by["switch_at_pct"]["value"] != 80.0 || by["switch_at_pct"]["default"] != 99.0 ||
		by["usage_minutes"]["level"] != "default" || by["usage_minutes"]["value"] != 5.0 ||
		!strings.Contains(str(by["usage_minutes"]["invalid"]), "outside its bound") ||
		!strings.Contains(str(by["room_below_pct"]["invalid"]), "above switch_at_pct 80") ||
		!strings.Contains(str(by["warn_at_pct"]["invalid"]), "85") || by["switch_auto"]["invalid"] != nil {
		t.Fatalf("settings %v", by)
	}
	r.ConfigLevels = func(context.Context) (map[string]string, error) { return nil, errors.New("no responders") }
	for _, tool := range r.Tools() {
		if tool.Name == "licences_settings" {
			if _, err := tool.Run(nil); err == nil {
				t.Fatal("mesh-config not answering is answered as the default")
			}
		}
	}
}

// design 39 bus-and-switch §41/AC1, design 39 parts §3, §10: every bus-state entry the manifest asks for is read by
// licences_kept, with its keys or subjects, one key's value and its fill, the carry-over's record among them; an
// entry not kept is refused; nothing is written.
func TestKeptReadsEveryEntryOfTheManifest(t *testing.T) {
	raw, err := os.ReadFile("../../module.json")
	if err != nil {
		t.Fatal(err)
	}
	var m struct {
		Requires []struct {
			Name     string `json:"name"`
			Template string `json:"template"`
		} `json:"requires"`
		Logs []struct {
			Name string `json:"name"`
		} `json:"logs"`
	}
	if err := json.Unmarshal(raw, &m); err != nil {
		t.Fatal(err)
	}
	rt := newRuntime(t)
	rt.seedState(licences.EntryLicences, "a_at_example.org", licences.Licence{Name: "a@example.org", Kind: "subscription"})
	rt.seedState(licences.EntryCarried, "postgres", map[string]any{"at": "2026-11-12T09:44:59Z"})
	rt.seedLog(licences.EntryUsage, "a_at_example.org", licences.UsageEntry{At: "2026-11-12T10:00:00Z"})
	r := rt.reader()
	all := run(t, r, "licences_kept", nil).(map[string]any)
	kinds := map[string]string{}
	for _, e := range m.Requires {
		kinds[e.Name] = e.Template
	}
	for _, l := range m.Logs {
		kinds[l.Name] = "log"
	}
	for name, kind := range kinds {
		got, ok := all[name].(map[string]any)
		if !ok || got["fill"] == nil || got["kind"] != kind {
			t.Errorf("licences_kept does not read %s as a %s: %v", name, kind, all[name])
		}
	}
	if len(kinds) != 8 || len(all) != len(kinds) {
		t.Fatalf("the manifest asks for %d entries, licences_kept reads %d", len(kinds), len(all))
	}
	one := run(t, r, "licences_kept", map[string]any{"entry": "carried", "key": "postgres"}).(map[string]any)
	if v, _ := one["carried"].(map[string]any)["value"].(map[string]any); v["at"] != "2026-11-12T09:44:59Z" {
		t.Fatalf("the carry-over's record %v", one)
	}
	if subjects := all["usage"].(map[string]any)["subjects"].(map[string]any); subjects["a_at_example.org"] == nil {
		t.Fatalf("usage subjects %v", subjects)
	}
	if _, err := r.Kept("tables", ""); err == nil {
		t.Fatal("an entry not kept is answered")
	}
}

// design 39 bus-and-switch §43/AC1, design 39 parts §3: each key of conditions is answered with its body and since.
func TestConditionsAnswersEachKey(t *testing.T) {
	rt := newRuntime(t)
	for _, k := range []string{"settings.room_below_pct.invalid", "licence.a.near-limit"} {
		rt.seedState(licences.EntryConditions, k, licences.KeptCondition{Body: oc.Condition{Key: k, Headline: "h"},
			Since: "2026-11-12T10:00:00Z"})
	}
	var keys []string
	for _, c := range run(t, rt.reader(), "licences_conditions", nil).([]any) {
		f := c.(map[string]any)
		if f["since"] == "" || f["body"].(map[string]any)["headline"] == "" {
			t.Fatalf("condition %v", f)
		}
		keys = append(keys, f["body"].(map[string]any)["key"].(string))
	}
	if strings.Join(keys, ",") != "licence.a.near-limit,settings.room_below_pct.invalid" {
		t.Fatalf("keys %v", keys)
	}
}