package main

import (
	"context"
	"encoding/json"
	"os"
	"path/filepath"
	"strings"
	"testing"
	"time"
)

type recorder struct {
	created  []Provision
	removed  []string
	held     bool
	failing  error
	holdsErr error
}

func (r *recorder) Create(_ context.Context, p Provision) error {
	if r.failing != nil {
		return r.failing
	}
	r.created = append(r.created, p)
	return nil
}

func (r *recorder) Remove(_ context.Context, as string, _ map[string]any) error {
	r.removed = append(r.removed, as)
	return nil
}

func (r *recorder) Holds(context.Context, Provision) (bool, error) {
	if r.holdsErr != nil {
		return false, r.holdsErr
	}
	return r.held, nil
}

type world struct {
	t        *testing.T
	dir      string
	receives string
	now      time.Time
	h        *Harness
	a        *recorder
	said     []string
}

func newWorld(t *testing.T) *world {
	w := &world{t: t, dir: t.TempDir(), now: time.Date(2026, 10, 5, 12, 0, 0, 0, time.UTC), a: &recorder{held: true}}
	w.receives = filepath.Join(w.dir, "mesh.json")
	w.h = &Harness{Resource: "postgres-database", Receives: w.receives, Adapter: w.a,
		Now: func() time.Time { return w.now },
		Log: func(f string, a ...any) { w.said = append(w.said, f) }}
	return w
}

func (w *world) give(given ...map[string]any) {
	for _, g := range given {
		secret := filepath.Join(w.dir, g["as"].(string)+".secret")
		if err := os.WriteFile(secret, []byte("pw-"+g["as"].(string)+"\n"), 0o600); err != nil {
			w.t.Fatal(err)
		}
		g["secret"] = secret
	}
	if given == nil {
		given = []map[string]any{}
	}
	raw, _ := json.Marshal(map[string]any{"requirement": "postgres-database", "given": given})
	if err := os.WriteFile(w.receives, raw, 0o600); err != nil {
		w.t.Fatal(err)
	}
}

func TestAConsumerIsCreatedOnceUnderTheMeshsLoginAndPassword(t *testing.T) {
	w := newWorld(t)
	w.give(map[string]any{"as": "mesh_ace_letta", "node": "ace", "values": map[string]any{"name": "letta"}})
	w.h.Reconcile(ctx)
	w.h.Reconcile(ctx)
	if len(w.a.created) != 1 {
		t.Fatalf("created %d times", len(w.a.created))
	}
	p := w.a.created[0]
	if p.As != "mesh_ace_letta" || p.Password != "pw-mesh_ace_letta" || p.Consumer != "ace" {
		t.Fatalf("%+v", p)
	}
}

func TestAddingExtensionsAppliesTheConsumerAgain(t *testing.T) {
	w := newWorld(t)
	w.give(map[string]any{"as": "mesh_ace_letta", "values": map[string]any{"name": "letta"}})
	w.h.Reconcile(ctx)
	w.give(map[string]any{"as": "mesh_ace_letta", "values": map[string]any{"name": "letta", "extensions": []any{"vector"}}})
	w.h.Reconcile(ctx)
	if len(w.a.created) != 2 {
		t.Fatalf("created %d times", len(w.a.created))
	}
	if ext, _ := Extensions(w.a.created[1].Values); len(ext) != 1 || ext[0] != "vector" {
		t.Fatal(ext)
	}
}

func TestAConsumerNoLongerAskedForIsWithdrawn(t *testing.T) {
	w := newWorld(t)
	w.give(map[string]any{"as": "a"}, map[string]any{"as": "b"})
	w.h.Reconcile(ctx)
	w.give(map[string]any{"as": "a"})
	w.h.Reconcile(ctx)
	if strings.Join(w.a.removed, ",") != "b" {
		t.Fatal(w.a.removed)
	}
	// Only a file that says nobody asks withdraws everybody.
	w.give()
	w.h.Reconcile(ctx)
	if strings.Join(w.a.removed, ",") != "b,a" {
		t.Fatal(w.a.removed)
	}
}

func TestNothingReadIsNotNobodyAsking(t *testing.T) {
	for name, content := range map[string]string{
		"unreadable": "",
		"not JSON":   "{",
		"no given":   `{"requirement": "postgres-database"}`,
		"another":    `{"requirement": "mssql-database", "given": []}`,
	} {
		t.Run(name, func(t *testing.T) {
			w := newWorld(t)
			w.give(map[string]any{"as": "a"})
			w.h.Reconcile(ctx)
			if content == "" {
				os.Remove(w.receives)
			} else {
				os.WriteFile(w.receives, []byte(content), 0o600)
			}
			w.h.Reconcile(ctx)
			if len(w.a.removed) != 0 {
				t.Fatalf("withdrew %v on a file it could not use", w.a.removed)
			}
		})
	}
}

func TestALostConsumerIsAppliedAgainAndBraked(t *testing.T) {
	w := newWorld(t)
	w.give(map[string]any{"as": "a"})
	w.h.Reconcile(ctx)
	w.a.held = false
	w.now = w.now.Add(2 * time.Minute)
	w.h.Reconcile(ctx)
	if len(w.a.created) != 2 {
		t.Fatalf("created %d times", len(w.a.created))
	}
	// Still not held a minute later: applied again, then braked for two minutes.
	w.now = w.now.Add(61 * time.Second)
	w.h.Reconcile(ctx)
	w.now = w.now.Add(61 * time.Second)
	w.h.Reconcile(ctx)
	if len(w.a.created) != 3 {
		t.Fatalf("not braked: created %d times", len(w.a.created))
	}
}

func TestAFailingCreateIsRetriedAndSaidOnce(t *testing.T) {
	w := newWorld(t)
	w.a.failing = &pgErr{"extension \"nope\" refused, password pw-a"}
	w.give(map[string]any{"as": "a"})
	for i := 0; i < 5; i++ {
		w.h.Reconcile(ctx)
	}
	n := 0
	for _, s := range w.said {
		if strings.Contains(s, "create failed") {
			n++
		}
	}
	if n != 1 {
		t.Fatalf("said %d times", n)
	}
	w.a.failing = nil
	w.h.Reconcile(ctx)
	if len(w.a.created) != 1 {
		t.Fatal("not retried")
	}
}

type pgErr struct{ s string }

func (e *pgErr) Error() string { return e.s }

func TestScrubRemovesThePassword(t *testing.T) {
	if got := scrub(&pgErr{"bad pw a/b c and a%2Fb+c"}, "a/b c"); strings.Contains(got, "a/b c") || strings.Contains(got, "a%2Fb+c") {
		t.Fatal(got)
	}
}

func TestProvisionerCreatesTheDatabaseThenItsExtensions(t *testing.T) {
	f, c := newFake(admin)
	f.answer(`FROM pg_available_extensions`, []string{"name"}, []string{"vector"})
	var events []string
	a := provisioner{pg: c, announce: func(e string, _ map[string]string) { events = append(events, e) }}
	p := Provision{As: "mesh_ace_letta", Password: "pw", Values: map[string]any{"name": "letta", "extensions": []any{"vector"}}}
	if err := a.Create(ctx, p); err != nil {
		t.Fatal(err)
	}
	sql := f.statements()
	if !strings.HasPrefix(sql[len(sql)-1], `CREATE EXTENSION IF NOT EXISTS "vector"`) || !has(sql, `CREATE DATABASE "mesh_ace_letta"`) {
		t.Fatal(strings.Join(sql, "\n"))
	}
	if strings.Join(events, ",") != "database.provisioned" {
		t.Fatal(events)
	}

	// An extension the server does not offer: refused, and no event says it was provisioned.
	events = nil
	p.Values = map[string]any{"extensions": []any{"nope"}}
	if err := a.Create(ctx, p); err == nil || !strings.Contains(err.Error(), `"nope"`) || len(events) != 0 {
		t.Fatal(err, events)
	}
	// A malformed list: refused before the server is asked anything.
	f.reset()
	p.Values = map[string]any{"extensions": "vector"}
	if err := a.Create(ctx, p); err == nil || len(f.calls) != 0 {
		t.Fatal(err, f.calls)
	}

	f.reset()
	f.answer(`FROM pg_roles`, []string{"?column?"}, []string{"1"})
	if err := a.Remove(ctx, "mesh_ace_letta", nil); err != nil {
		t.Fatal(err)
	}
	noDrop(t, f.statements())
	if !has(f.statements(), `NOLOGIN`) {
		t.Fatal(f.statements())
	}
}