generate is coo

.gitignore

@@ -1 +1,2 @@
 **/*.sw*
+/src/state/fsm/template

src/state/fsm/.template/events.go

@@ -0,0 +1,44 @@
+package template
+
+import (
+	"context"
+	"gitea/price-is-wrong/src/lib/db"
+	template "gitea/price-is-wrong/src/state/fsm/template/internal"
+	"io"
+)
+
+func (t *Template) TODO(ctx context.Context, id int) error {
+	return io.EOF
+}
+
+func (t *Template) upsertEvent(ctx context.Context, e template.Event) error {
+	if err := upsertEvent(ctx, p.id, e); err != nil {
+		return err
+	}
+
+	p2, err := openID(ctx, p.id)
+	if err != nil {
+		return err
+	}
+
+	*p = *p2
+	return nil
+}
+
+func upsertEvent(ctx context.Context, templateID int, e template.Event) error {
+	b, err := template.MarshalEvent(e)
+	if err != nil {
+		return err
+	}
+
+	_, err = db.From(ctx).ExecContext(ctx, `
+      INSERT INTO template_events (template_id, payload) VALUES (?, ?)
+   `, templateID, b)
+	return err
+}
+
+func (t *Template) apply(e template.Event) error {
+	switch e := e.(type) {
+	}
+	return nil
+}

src/state/fsm/.template/internal/event.go

@@ -0,0 +1,20 @@
+package template
+
+import (
+	"fmt"
+	"gitea/price-is-wrong/src/lib/event"
+)
+
+type Event interface{}
+
+func ParseEvent(b []byte) (Event, error) {
+	typesToPointers := map[string]any{
+		"*any": &b,
+	}
+	t, err := event.Parse(b, typesToPointers)
+	return typesToPointers[t], err
+}
+
+func MarshalEvent(e Event) ([]byte, error) {
+	return event.Serialize(fmt.Sprintf("%T", e), e)
+}

src/state/fsm/.template/open.go

@@ -0,0 +1,115 @@
+package template
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+	"gitea/price-is-wrong/src/lib/db"
+	template "gitea/price-is-wrong/src/state/fsm/template/internal"
+)
+
+type Template struct {
+	id          int
+	Host        int
+	Contestants Player
+}
+
+type Player struct {
+	ID int
+}
+
+func Open(ctx context.Context, name string) (*Template, error) {
+	if err := initialize(ctx); err != nil {
+		return nil, fmt.Errorf("failed to initialize template: %w", err)
+	}
+
+	if result, err := open(ctx, name); err != nil {
+		return nil, err
+	} else if result == nil {
+		if err := create(ctx, name); err != nil {
+			return nil, err
+		}
+	}
+
+	return mustOpen(ctx, name)
+}
+
+func mustOpen(ctx context.Context, name string) (*Template, error) {
+	result, err := open(ctx, name)
+	if err != nil {
+		return nil, err
+	}
+	if result == nil {
+		return nil, fmt.Errorf("no template found with name %s", name)
+	}
+	return result, nil
+}
+
+func open(ctx context.Context, name string) (*Template, error) {
+	row := db.From(ctx).QueryRow(`SELECT id FROM templates WHERE name=?`, name)
+	if err := row.Err(); err != nil {
+		return nil, fmt.Errorf("no template found with name %s", name)
+	}
+
+	var id sql.NullInt32
+	if err := row.Scan(&id); err == sql.ErrNoRows || !id.Valid {
+		return nil, nil
+	} else if err != nil {
+		return nil, fmt.Errorf("failed to scan id from templates: %w", err)
+	}
+
+	return openID(ctx, int(id.Int32))
+}
+
+func openID(ctx context.Context, id int) (*Template, error) {
+	rows, err := db.From(ctx).QueryContext(ctx, `
+      SELECT payload
+      FROM template_events
+      WHERE template_events.template_id=?
+      ORDER BY id
+   `, id)
+	if err != nil {
+		return nil, fmt.Errorf("failed to query event payloads for id %d: %w", id, err)
+	}
+	defer rows.Close()
+
+	result := Template{id: id}
+	for rows.Next() {
+		var b []byte
+		if err := rows.Scan(&b); err != nil {
+			return nil, fmt.Errorf("failed to scan event: %w", err)
+		}
+		event, err := template.ParseEvent(b)
+		if err != nil {
+			return nil, fmt.Errorf("failed to parse event: %w", err)
+		}
+		if err := result.apply(event); err != nil {
+			return nil, fmt.Errorf("failed to apply event %s: %w", b, err)
+		}
+	}
+
+	return &result, rows.Err()
+}
+
+func create(ctx context.Context, name string) error {
+	_, err := db.From(ctx).ExecContext(ctx, `
+      INSERT INTO templates (name) VALUES (?)
+   `, name)
+	return err
+}
+
+func initialize(ctx context.Context) error {
+	_, err := db.From(ctx).ExecContext(ctx, `
+      CREATE TABLE IF NOT EXISTS templates (
+         id INTEGER PRIMARY KEY,
+         name TEXT
+      );
+      CREATE TABLE IF NOT EXISTS template_events (
+         id INTEGER PRIMARY KEY,
+         template_id NUMBER,
+         payload TEXT,
+         FOREIGN KEY (template_id) REFERENCES templates (id)
+      );
+   `)
+	return err
+}

src/state/fsm/generate.go

@@ -0,0 +1,3 @@
+package fsm
+
+//go:generate cp -r ./.template ./template