Refactor to simplify dot config

TODO.md

@@ -66,8 +66,6 @@
 - [ ] See if its possible to implement sql queryrows with https://go.dev/wiki/RangefuncExperiment
   - Not until caddy releases 2.8.0 and upgrades to 1.22.
 - [ ] Add command that pre-compresses static files
-- [ ] Schema migration? https://david.rothlis.net/declarative-schema-migration-for-sqlite/
-- [ ] Schema generator: https://gitlab.com/Screwtapello/sqlite-schema-diagram/-/blob/main/sqlite-schema-diagram.sql?ref_type=heads
 - [ ] Add a way to register additional routes dynamically during init
 - [ ] Organize docs according to https://diataxis.fr/
 - [ ] Research alternative template loading strategies:

cmd/main.go

@@ -5,9 +5,6 @@ package main
 import (
 	"github.com/infogulch/xtemplate/app"
 
-	_ "github.com/infogulch/xtemplate/providers"
-	_ "github.com/infogulch/xtemplate/providers/nats"
-
 	_ "github.com/mattn/go-sqlite3"
 )
 

config.go

@@ -8,6 +8,8 @@ import (
 	"html/template"
 	"io/fs"
 	"log/slog"
+
+	"github.com/nats-io/nats-server/v2/server"
 )
 
 func New() (c *Config) {
@@ -26,19 +28,26 @@ type Config struct {
 	// File extension to search for to find template files. Default `.html`.
 	TemplateExtension string `json:"template_extension,omitempty" arg:"--template-ext" default:".html"`
 
+	// Whether html templates are minified at load time. Default `true`.
+	Minify bool `json:"minify,omitempty" arg:"-m,--minify" default:"true"`
+
+	Databases       []DotDBConfig     `json:"databases" arg:"-"`
+	Flags           []DotFlagsConfig  `json:"flags" arg:"-"`
+	Directories     []DotDirConfig    `json:"directories" arg:"-"`
+	KVs             []DotKVProvider   `json:"kvs" arg:"-"`
+	Nats            []DotNatsProvider `json:"nats" arg:"-"`
+	CustomProviders []DotProvider     `json:"-" arg:"-"`
+
+	// Whether to start a bult-in nats server
+	StartInternalNatsServer bool            `json:"start_internal_nats_server" default:"false"`
+	NatsServerOpts          *server.Options `arg:"-"`
+
 	// Left template action delimiter. Default `{{`.
 	LDelim string `json:"left,omitempty" arg:"--ldelim" default:"{{"`
 
 	// Right template action delimiter. Default `}}`.
 	RDelim string `json:"right,omitempty" arg:"--rdelim" default:"}}"`
 
-	// Whether html templates are minified at load time. Default `true`.
-	Minify bool `json:"minify,omitempty" arg:"-m,--minify" default:"true"`
-
-	// A list of additional custom fields to add to the template dot value
-	// `{{.}}`.
-	Dot []DotConfig `json:"dot" arg:"-d,--dot,separate"`
-
 	// Additional functions to add to the template execution context.
 	FuncMaps []template.FuncMap `json:"-" arg:"-"`
 
@@ -50,6 +59,40 @@ type Config struct {
 	Logger *slog.Logger `json:"-" arg:"-"`
 }
 
+func (config *Config) CheckName(name string) error {
+	for _, d := range config.Databases {
+		if name == d.FieldName() {
+			return fmt.Errorf("field name '%s' conflicts with database field name '%s'", name, d.FieldName())
+		}
+	}
+	for _, f := range config.Flags {
+		if name == f.FieldName() {
+			return fmt.Errorf("field name '%s' conflicts with flags field name '%s'", name, f.FieldName())
+		}
+	}
+	for _, d := range config.Directories {
+		if name == d.FieldName() {
+			return fmt.Errorf("field name '%s' conflicts with directory field name '%s'", name, d.FieldName())
+		}
+	}
+	for _, kv := range config.KVs {
+		if name == kv.FieldName() {
+			return fmt.Errorf("field name '%s' conflicts with flags field name '%s'", name, kv.FieldName())
+		}
+	}
+	for _, d := range config.Nats {
+		if name == d.FieldName() {
+			return fmt.Errorf("field name '%s' conflicts with directory field name '%s'", name, d.FieldName())
+		}
+	}
+	for _, d := range config.CustomProviders {
+		if name == d.FieldName() {
+			return fmt.Errorf("field name '%s' conflicts with directory field name '%s'", name, d.FieldName())
+		}
+	}
+	return nil
+}
+
 // FillDefaults sets default values for unset fields
 func (config *Config) Defaults() *Config {
 	if config.TemplatesDir == "" {
@@ -117,17 +160,12 @@ func WithFuncMaps(fm ...template.FuncMap) Option {
 	}
 }
 
-func WithProvider(name string, p DotProvider) Option {
+func WithProvider(p DotProvider) Option {
 	return func(c *Config) error {
-		for _, d := range c.Dot {
-			if d.Name == name {
-				if d.DotProvider != p {
-					return fmt.Errorf("tried to assign different providers the same name. name: %s; old: %v; new: %v", d.Name, d.DotProvider, p)
-				}
-				return nil
-			}
+		if err := c.CheckName(p.FieldName()); err != nil {
+			return err
 		}
-		c.Dot = append(c.Dot, DotConfig{Name: name, DotProvider: p})
+		c.CustomProviders = append(c.CustomProviders, p)
 		return nil
 	}
 }

dot.go

@@ -1,36 +1,16 @@
 package xtemplate
 
 import (
-	"bytes"
 	"context"
-	"encoding"
-	"encoding/json"
 	"fmt"
 	"net/http"
 	"net/http/httptest"
 	"reflect"
-	"slices"
 	"sync"
 )
 
-var registrations map[string]RegisteredDotProvider = make(map[string]RegisteredDotProvider)
-
-func RegisterDot(r RegisteredDotProvider) {
-	name := r.Type()
-	if old, ok := registrations[name]; ok {
-		panic(fmt.Sprintf("DotProvider name already registered: %s (%v)", name, old))
-	}
-	registrations[name] = r
-}
-
-type DotConfig struct {
-	Name        string `json:"name"`
-	Type        string `json:"type"`
-	DotProvider `json:"-"`
-}
-
 type Request struct {
-	DotConfig
+	DotProvider
 	ServerCtx context.Context
 	W         http.ResponseWriter
 	R         *http.Request
@@ -41,125 +21,42 @@ type DotProvider interface {
 	// also returns an error. Value will be called with mock values at least
 	// once and still must not panic.
 	Value(Request) (any, error)
-}
 
-type RegisteredDotProvider interface {
-	DotProvider
-	Type() string
-	New() DotProvider
+	FieldName() string
 }
 
 type CleanupDotProvider interface {
 	DotProvider
 	Cleanup(any, error) error
 }
 
-var _ encoding.TextMarshaler = &DotConfig{}
-
-func (d *DotConfig) MarshalText() ([]byte, error) {
-	var parts [][]byte
-	if r, ok := d.DotProvider.(RegisteredDotProvider); ok {
-		parts = [][]byte{[]byte(d.Name), {':'}, []byte(r.Type())}
-	} else {
-		return nil, fmt.Errorf("dot provider cannot be marshalled: %v (%T)", d.DotProvider, d.DotProvider)
-	}
-	if m, ok := d.DotProvider.(encoding.TextMarshaler); ok {
-		b, err := m.MarshalText()
-		if err != nil {
-			return nil, err
-		}
-		parts = append(parts, []byte{':'}, b)
-	}
-	return slices.Concat(parts...), nil
-}
-
-var _ encoding.TextUnmarshaler = &DotConfig{}
-
-func (d *DotConfig) UnmarshalText(b []byte) error {
-	parts := bytes.SplitN(b, []byte{':'}, 3)
-	if len(parts) < 2 {
-		return fmt.Errorf("failed to parse DotConfig not enough sections. required format: NAME:PROVIDER_NAME[:PROVIDER_CONFIG]")
-	}
-	name, providerType := string(parts[0]), string(parts[1])
-	reg, ok := registrations[providerType]
-	if !ok {
-		return fmt.Errorf("dot provider with name '%s' is not registered", providerType)
-	}
-	d.Name = name
-	d.Type = providerType
-	d.DotProvider = reg.New()
-	if unm, ok := d.DotProvider.(encoding.TextUnmarshaler); ok {
-		var rest []byte
-		if len(parts) == 3 {
-			rest = parts[2]
-		}
-		err := unm.UnmarshalText(rest)
-		if err != nil {
-			return fmt.Errorf("failed to configure provider %s: %w", providerType, err)
-		}
-	}
-	return nil
-}
-
-var _ json.Marshaler = &DotConfig{}
-
-func (d *DotConfig) MarshalJSON() ([]byte, error) {
-	type T DotConfig
-	return json.Marshal((*T)(d))
-}
-
-var _ json.Unmarshaler = &DotConfig{}
-
-func (d *DotConfig) UnmarshalJSON(b []byte) error {
-	type T DotConfig
-	dc := T{}
-	if err := json.Unmarshal(b, &dc); err != nil {
-		return err
-	}
-	r, ok := registrations[dc.Type]
-	if !ok {
-		return fmt.Errorf("no provider registered with the type '%s': %+v", dc.Type, dc)
-	}
-	p := r.New()
-	if err := json.Unmarshal(b, p); err != nil {
-		return fmt.Errorf("failed to decode provider %s (%v): %w", dc.Type, p, err)
-	}
-	d.Name = dc.Name
-	d.Type = dc.Type
-	d.DotProvider = p
-	return nil
-}
-
-func makeDot(dcs []DotConfig) dot {
-	fields := make([]reflect.StructField, 0, len(dcs))
+func makeDot(dps []DotProvider) dot {
+	fields := make([]reflect.StructField, 0, len(dps))
 	cleanups := []cleanup{}
 	mockHttpRequest := httptest.NewRequest("GET", "/", nil)
-	for i, dc := range dcs {
-		mockRequest := Request{dc, context.Background(), mockResponseWriter{}, mockHttpRequest}
-		a, _ := dc.DotProvider.Value(mockRequest)
+	for i, dp := range dps {
+		mockRequest := Request{dp, context.Background(), mockResponseWriter{}, mockHttpRequest}
+		a, _ := dp.Value(mockRequest)
 		t := reflect.TypeOf(a)
 		if t.Kind() == reflect.Interface && t.NumMethod() == 0 {
 			t = t.Elem()
 		}
 		f := reflect.StructField{
-			Name:      dc.Name,
+			Name:      dp.FieldName(),
 			Type:      t,
 			Anonymous: false, // alas
 		}
-		if f.Name == "" {
-			f.Name = f.Type.Name()
-		}
 		fields = append(fields, f)
-		if cdp, ok := dc.DotProvider.(CleanupDotProvider); ok {
+		if cdp, ok := dp.(CleanupDotProvider); ok {
 			cleanups = append(cleanups, cleanup{i, cdp})
 		}
 	}
 	typ := reflect.StructOf(fields)
-	return dot{dcs, cleanups, &sync.Pool{New: func() any { v := reflect.New(typ).Elem(); return &v }}}
+	return dot{dps, cleanups, &sync.Pool{New: func() any { v := reflect.New(typ).Elem(); return &v }}}
 }
 
 type dot struct {
-	dcs      []DotConfig
+	dps      []DotProvider
 	cleanups []cleanup
 	pool     *sync.Pool
 }
@@ -172,11 +69,11 @@ type cleanup struct {
 func (d *dot) value(sctx context.Context, w http.ResponseWriter, r *http.Request) (val *reflect.Value, err error) {
 	val = d.pool.Get().(*reflect.Value)
 	val.SetZero()
-	for i, dc := range d.dcs {
+	for i, dp := range d.dps {
 		var a any
-		a, err = dc.Value(Request{dc, sctx, w, r})
+		a, err = dp.Value(Request{dp, sctx, w, r})
 		if err != nil {
-			err = fmt.Errorf("failed to construct dot value for %s (%v): %w", dc.Name, dc.DotProvider, err)
+			err = fmt.Errorf("failed to construct dot value for %s (%v): %w", dp.FieldName(), dp, err)
 			val.SetZero()
 			d.pool.Put(val)
 			val = nil

providers/db.go → dot_db.go

@@ -1,4 +1,4 @@
-package providers
+package xtemplate
 
 import (
 	"context"

dot_db_config.go

@@ -0,0 +1,55 @@
+package xtemplate
+
+import (
+	"database/sql"
+	"errors"
+	"fmt"
+)
+
+func WithDB(name string, db *sql.DB, opt *sql.TxOptions) Option {
+	return func(c *Config) error {
+		if db == nil {
+			return fmt.Errorf("cannot create database provider with nil sql.DB. name: %s", name)
+		}
+		if err := c.CheckName(name); err != nil {
+			return err
+		}
+		c.Databases = append(c.Databases, DotDBConfig{Name: name, DB: db, TxOptions: opt})
+		return nil
+	}
+}
+
+type DotDBConfig struct {
+	*sql.DB        `json:"-"`
+	*sql.TxOptions `json:"-"`
+	Name           string `json:"name"`
+	Driver         string `json:"driver"`
+	Connstr        string `json:"connstr"`
+	MaxOpenConns   int    `json:"max_open_conns"`
+}
+
+var _ CleanupDotProvider = &DotDBConfig{}
+
+func (d *DotDBConfig) FieldName() string { return d.Name }
+func (d *DotDBConfig) Value(r Request) (any, error) {
+	if d.DB == nil {
+		db, err := sql.Open(d.Driver, d.Connstr)
+		if err != nil {
+			return &DotDB{}, fmt.Errorf("failed to open database with driver name '%s': %w", d.Driver, err)
+		}
+		db.SetMaxOpenConns(d.MaxOpenConns)
+		if err := db.Ping(); err != nil {
+			return &DotDB{}, fmt.Errorf("failed to ping database on open: %w", err)
+		}
+		d.DB = db
+	}
+	return &DotDB{d.DB, GetLogger(r.R.Context()), r.R.Context(), d.TxOptions, nil}, nil
+}
+func (dp *DotDBConfig) Cleanup(v any, err error) error {
+	d := v.(*DotDB)
+	if err != nil {
+		return errors.Join(err, d.rollback())
+	} else {
+		return errors.Join(err, d.commit())
+	}
+}