package main

import (
	"encoding/json"
	"errors"
	"fmt"
	"net/http"
	"path/filepath"
	"slices"
	"strings"
	"testing"
	"time"
)

func TestPickCoreFirstThenBorrow(t *testing.T) {
	f := NewFlock(MockBrain{}, DefaultGuardrails(), nil)
	nest := Nest{ID: "launch", Crows: []string{"Pepper", "Inky"}}

	// Within the core, picks rotate.
	if got := f.pick(nest, 1); !slices.Equal(got, []string{"Pepper"}) {
		t.Fatalf("first solo pick: %v", got)
	}
	if got := f.pick(nest, 1); !slices.Equal(got, []string{"Inky"}) {
		t.Fatalf("second solo pick should rotate within the core: %v", got)
	}

	// A murder of 3 needs one more than the core: the whole core flies, plus one borrowed.
	got := f.pick(nest, 3)
	if !slices.Contains(got, "Pepper") || !slices.Contains(got, "Inky") {
		t.Fatalf("core crows should fly first: %v", got)
	}
	if got[2] != "Hugin" {
		t.Fatalf("first borrowed crow should be the first roster crow outside the core: %v", got)
	}
	// Borrowing rotates too, and never picks a core crow.
	if got := f.pick(nest, 3); got[2] != "Munin" {
		t.Fatalf("borrowing should rotate: %v", got)
	}

	// The todo nest keeps the old whole-flock rotation, unaffected by other nests.
	if got := f.pick(defaultNest, 3); !slices.Equal(got, roster[:3]) {
		t.Fatalf("todo nest should rotate the whole roster: %v", got)
	}
}

func TestPickWholeFlockCore(t *testing.T) {
	f := NewFlock(MockBrain{}, DefaultGuardrails(), nil)
	nest := Nest{ID: "all", Crows: slices.Clone(roster)}
	got := f.pick(nest, 3)
	if !slices.Equal(got, roster[:3]) {
		t.Fatalf("got %v", got)
	}
}

func TestNestValidation(t *testing.T) {
	s, _ := LoadNests(filepath.Join(t.TempDir(), "nests.json"))
	bad := []struct {
		name  string
		crows []string
	}{
		{"   ", []string{"Pepper"}},
		{strings.Repeat("a", 41), []string{"Pepper"}},
		{"!!!", []string{"Pepper"}},
		{"No crows", nil},
		{"Too many", append(slices.Clone(roster), "Hugin")},
		{"Stranger", []string{"Pepper", "Tweety"}},
		{"Sentry inside", []string{"Sentry"}},
		{"Twice", []string{"Pepper", "Pepper"}},
	}
	for _, b := range bad {
		_, err := s.Create(b.name, b.crows)
		var ne *NestError
		if err == nil || !errors.As(err, &ne) || ne.Clash {
			t.Errorf("Create(%q, %v): want invalid, got %v", b.name, b.crows, err)
		}
	}

	n, err := s.Create("  Launch -- Copy!  ", []string{"Pepper", "Inky"})
	if err != nil || n.ID != "launch-copy" || n.Name != "Launch -- Copy!" {
		t.Fatalf("got %+v, %v", n, err)
	}
	if _, err := s.Create(strings.Repeat("a", 40), []string{"Jet"}); err != nil {
		t.Fatalf("40 characters should be fine: %v", err)
	}
	for _, name := range []string{"launch copy", "TODO"} {
		_, err := s.Create(name, []string{"Jet"})
		var ne *NestError
		if !errors.As(err, &ne) || !ne.Clash {
			t.Errorf("Create(%q): want clash, got %v", name, err)
		}
	}
}

func TestNestsPersistAndCap(t *testing.T) {
	path := filepath.Join(t.TempDir(), "nests.json")
	s, _ := LoadNests(path)
	for i := 1; i < maxNests; i++ { // todo is nest number one
		if _, err := s.Create(fmt.Sprintf("Nest %d", i), []string{"Soot"}); err != nil {
			t.Fatalf("nest %d: %v", i, err)
		}
	}
	if _, err := s.Create("One too many", []string{"Soot"}); err == nil {
		t.Fatal("want the nest cap to refuse")
	}

	reloaded, err := LoadNests(path)
	if err != nil {
		t.Fatal(err)
	}
	all := reloaded.All()
	if len(all) != maxNests || all[0].ID != "todo" || all[1].ID != "nest-1" || all[maxNests-1].ID != "nest-19" {
		t.Fatalf("reload lost order or nests: %d nests, first %v", len(all), all[:2])
	}
	if n, ok := reloaded.Get("nest-7"); !ok || !slices.Equal(n.Crows, []string{"Soot"}) {
		t.Fatalf("Get after reload: %+v %v", n, ok)
	}
}

func TestServerNests(t *testing.T) {
	ts, _ := newTestServer(t, DefaultGuardrails(), time.Minute)

	var got struct {
		Roster []string `json:"roster"`
		Nests  []Nest   `json:"nests"`
	}
	getJSON(t, ts.URL+"/api/nests", &got)
	if !slices.Equal(got.Roster, roster) || len(got.Nests) != 1 || got.Nests[0].ID != "todo" || got.Nests[0].Crows == nil {
		t.Fatalf("GET /api/nests: %+v", got)
	}

	code, out := post(t, ts.URL+"/api/nests", `{"name":"Launch copy","crows":["Pepper","Inky"]}`)
	if code != http.StatusCreated || out["nest_id"] != "launch-copy" {
		t.Fatalf("create: %d %v", code, out)
	}
	if code, out := post(t, ts.URL+"/api/nests", `{"name":"launch  COPY","crows":["Jet"]}`); code != http.StatusConflict || out["message"] == nil {
		t.Fatalf("clash: want 409 with message, got %d %v", code, out)
	}
	if code, out := post(t, ts.URL+"/api/nests", `{"name":"Bad","crows":["Elder"]}`); code != http.StatusBadRequest || out["message"] == nil {
		t.Fatalf("bad crow: want 400 with message, got %d %v", code, out)
	}
	if code, _ := post(t, ts.URL+"/api/nests", `{"name":"x","crows":`+strings.Repeat(" ", maxBody)+`[]}`); code != http.StatusRequestEntityTooLarge {
		t.Fatalf("want 413, got %d", code)
	}
	getJSON(t, ts.URL+"/api/nests", &got)
	if len(got.Nests) != 2 || got.Nests[1].ID != "launch-copy" {
		t.Fatalf("after create: %+v", got.Nests)
	}

	if code, out := post(t, ts.URL+"/api/lists", `{"text":"Write a poem","requester":"t","nest_id":"nope"}`); code != http.StatusNotFound || out["message"] == nil {
		t.Fatalf("unknown nest: want 404 with message, got %d %v", code, out)
	}
}

func TestServerBorrowedEvents(t *testing.T) {
	ts, _ := newTestServer(t, DefaultGuardrails(), time.Minute)
	post(t, ts.URL+"/api/nests", `{"name":"Launch copy","crows":["Pepper","Inky"]}`)
	yes := true

	// "should" makes the mock Sentry call a murder of 3: the 2-crow core plus one borrowed.
	_, out := post(t, ts.URL+"/api/lists", `{"text":"Should we launch on a Tuesday","requester":"t","nest_id":"launch-copy"}`)
	events, _ := stream(t, ts, out["list_id"].(string), &yes)
	if events[0].Data["nest_id"] != "launch-copy" {
		t.Fatalf("list.started nest_id: %v", events[0].Data)
	}
	borrowed := flights(t, events)
	if !slices.Equal(borrowed["Pepper"], []bool{false}) || !slices.Equal(borrowed["Inky"], []bool{false}) ||
		!slices.Equal(borrowed["Hugin"], []bool{true}) || !slices.Equal(borrowed["Sentry"], []bool{false}) ||
		!slices.Equal(borrowed["Elder"], []bool{false}) {
		t.Fatalf("borrowed flags: %v", borrowed)
	}

	// The todo nest (the default) never borrows.
	_, out = post(t, ts.URL+"/api/lists", `{"text":"Should we launch on a Tuesday","requester":"t"}`)
	events, _ = stream(t, ts, out["list_id"].(string), &yes)
	if events[0].Data["nest_id"] != "todo" {
		t.Fatalf("default nest_id: %v", events[0].Data)
	}
	for crow, flags := range flights(t, events) {
		if slices.Contains(flags, true) {
			t.Fatalf("%s borrowed in the todo nest", crow)
		}
	}
}

// flights maps each crow to the borrowed flag of each of its crow.flying events.
func flights(t *testing.T, events []sseEvent) map[string][]bool {
	m := map[string][]bool{}
	for _, e := range events {
		if e.Name != "crow.flying" {
			continue
		}
		b, ok := e.Data["borrowed"].(bool)
		if !ok {
			t.Fatalf("crow.flying without a borrowed bool: %v", e.Data)
		}
		c := e.Data["crow"].(string)
		m[c] = append(m[c], b)
	}
	return m
}

func getJSON(t *testing.T, url string, v any) {
	resp, err := http.Get(url)
	if err != nil {
		t.Fatal(err)
	}
	defer resp.Body.Close()
	if resp.StatusCode != http.StatusOK {
		t.Fatalf("GET %s: %d", url, resp.StatusCode)
	}
	if err := json.NewDecoder(resp.Body).Decode(v); err != nil {
		t.Fatal(err)
	}
}