{{/*
Copyright 2019-present Facebook Inc. All rights reserved.
This source code is licensed under the Apache 2.0 license found
in the LICENSE file in the root directory of this source tree.
*/}}

{{ define "client" }}

{{ $pkg := base $.Config.Package }}
{{ template "header" $ }}

import (
	"log"

	"{{ $.Config.Package }}/migrate"
	{{ range $_, $n := $.Nodes }}
		"{{ $n.Config.Package }}/{{ $n.Package }}"
	{{- end }}

	"github.com/facebookincubator/ent/dialect"
	{{ range $_, $import := $.Storage.Imports -}}
		"{{ $import }}"
	{{ end -}}
)

// Client is the client that holds all ent builders.
type Client struct {
	config
	{{- if $.SupportMigrate }}
		// Schema is the client for creating, migrating and dropping schema.
		Schema *migrate.Schema
	{{- end }}
	{{- range $n := $.Nodes }}
		// {{ $n.Name }} is the client for interacting with the {{ $n.Name }} builders.
		{{ $n.Name }} *{{ $n.Name }}Client
	{{- end }}
	{{ template "client/fields/additional" $ }}
}

// NewClient creates a new client configured with the given options.
func NewClient(opts ...Option) *Client {
	cfg := config{log: log.Println, hooks: &hooks{}}
	cfg.options(opts...)
	client := &Client{config: cfg}
	client.init()
	return client
}

func (c *Client) init() {
	{{- if $.SupportMigrate }}
		c.Schema = migrate.NewSchema(c.driver)
	{{- end }}
	{{- range $n := $.Nodes }}
    	c.{{ $n.Name }} =  New{{ $n.Name }}Client(c.config)
	{{- end }}
}

// Open opens a connection to the database specified by the driver name and a
// driver-specific data source name, and returns a new client attached to it.
// Optional parameters can be added for configuring the client.
func Open(driverName, dataSourceName string, options ...Option) (*Client, error) {
	switch driverName {
	case {{ join $.Storage.Dialects ", " }}:
		{{- $tmpl := printf "dialect/%s/client/open" $.Storage -}}
		{{- xtemplate $tmpl . -}}
	default:
		return nil, fmt.Errorf("unsupported driver: %q", driverName)
	}
}

// Tx returns a new transactional client.
func (c *Client) Tx(ctx context.Context) (*Tx, error) {
	if _, ok := c.driver.(*txDriver); ok {
		return nil, fmt.Errorf("{{ $pkg }}: cannot start a transaction within a transaction")
	}
	tx, err := newTx(ctx, c.driver)
	if err != nil {
		return nil, fmt.Errorf("{{ $pkg }}: starting a transaction: %v", err)
	}
	cfg := config{driver: tx, log: c.log, debug: c.debug, hooks: c.hooks}
	return &Tx{
		config: cfg,
		{{ range $_, $n := $.Nodes -}}
			{{ $n.Name }}: New{{ $n.Name }}Client(cfg),
		{{ end -}}
	}, nil
}

{{- /* If the storage driver supports TxOptions (like SQL) */}}
{{- $tmpl = printf "dialect/%s/txoptions" $.Storage }}
{{- if hasTemplate $tmpl }}
    {{- xtemplate $tmpl . }}
{{- end }}

// Debug returns a new debug-client. It's used to get verbose logging on specific operations.
//
//	client.Debug().
//		{{ (index $.Nodes 0).Name }}.
//		Query().
//		Count(ctx)
//
func (c *Client) Debug() *Client {
	if c.debug {
		return c
	}
	cfg := config{driver: dialect.Debug(c.driver, c.log), log: c.log, debug: true, hooks: c.hooks}
	client := &Client{config: cfg}
	client.init()
	return client
}

// Close closes the database connection and prevents new queries from starting.
func (c *Client) Close() error {
	return c.driver.Close()
}

// Use adds the mutation hooks to all the entity clients.
// In order to add hooks to a specific client, call: `client.Node.Use(...)`.
func (c *Client) Use(hooks ...Hook) {
	{{- range $_, $n := $.Nodes }}
		c.{{ $n.Name }}.Use(hooks...)
	{{- end }}
}


{{ range $_, $n := $.Nodes }}
{{ $client := print $n.Name "Client" }}
// {{ $client }} is a client for the {{ $n.Name }} schema.
type {{ $client }} struct {
	config
}

{{ $rec := $n.Receiver }}{{ if eq $rec "c" }}{{ $rec = printf "%.2s" $n.Name | lower }}{{ end }}

// New{{ $client }} returns a client for the {{ $n.Name }} from the given config.
func New{{ $client }}(c config) *{{ $client }} {
	return &{{ $client }}{config: c}
}

// Use adds a list of mutation hooks to the hooks stack.
// A call to `Use(f, g, h)` equals to `{{ $n.Package }}.Hooks(f(g(h())))`.
func (c *{{ $client }}) Use(hooks ...Hook) {
	c.hooks.{{ $n.Name }} = append(c.hooks.{{ $n.Name }}, hooks...)
}

// Create returns a create builder for {{ $n.Name }}.
func (c *{{ $client }}) Create() *{{ $n.Name }}Create {
	mutation := new{{ $n.MutationName }}(c.config, OpCreate)
	return &{{ $n.Name }}Create{config: c.config, hooks: c.Hooks(), mutation: mutation}
}

// Update returns an update builder for {{ $n.Name }}.
func (c *{{ $client }}) Update() *{{ $n.Name }}Update {
	mutation := new{{ $n.MutationName }}(c.config, OpUpdate)
	return &{{ $n.Name }}Update{config: c.config, hooks: c.Hooks(), mutation: mutation}
}

// UpdateOne returns an update builder for the given entity.
func (c *{{ $client }}) UpdateOne({{ $rec }} *{{ $n.Name }}) *{{ $n.Name }}UpdateOne {
	return c.UpdateOneID({{ $rec }}.ID)
}

// UpdateOneID returns an update builder for the given id.
func (c *{{ $client }}) UpdateOneID(id {{ $n.ID.Type }}) *{{ $n.Name }}UpdateOne {
	mutation := new{{ $n.MutationName }}(c.config, OpUpdateOne)
	mutation.id = &id
	return &{{ $n.Name }}UpdateOne{config: c.config, hooks: c.Hooks(), mutation: mutation}
}

// Delete returns a delete builder for {{ $n.Name }}.
func (c *{{ $client }}) Delete() *{{ $n.Name }}Delete {
	mutation := new{{ $n.MutationName }}(c.config, OpDelete)
	return &{{ $n.Name }}Delete{config: c.config, hooks: c.Hooks(), mutation: mutation}
}

// DeleteOne returns a delete builder for the given entity.
func (c *{{ $client }}) DeleteOne({{ $rec }} *{{ $n.Name }}) *{{ $n.Name }}DeleteOne {
	return c.DeleteOneID({{ $rec }}.ID)
}

// DeleteOneID returns a delete builder for the given id.
func (c *{{ $client }}) DeleteOneID(id {{ $n.ID.Type }}) *{{ $n.Name }}DeleteOne {
	builder := c.Delete().Where({{ $n.Package }}.ID(id))
	builder.mutation.id = &id
	builder.mutation.op = OpDeleteOne
	return &{{ $n.Name }}DeleteOne{builder}
}

// Create returns a query builder for {{ $n.Name }}.
func (c *{{ $client }}) Query() *{{ $n.Name }}Query {
	return &{{ $n.Name }}Query{config: c.config}
}

// Get returns a {{ $n.Name }} entity by its id.
func (c *{{ $client }}) Get(ctx context.Context, id {{ $n.ID.Type }}) (*{{ $n.Name }}, error) {
	return c.Query().Where({{ $n.Package }}.ID(id)).Only(ctx)
}

// GetX is like Get, but panics if an error occurs.
func (c *{{ $client }}) GetX(ctx context.Context, id {{ $n.ID.Type }}) *{{ $n.Name }} {
	{{ $rec }}, err := c.Get(ctx, id)
	if err != nil {
		panic(err)
	}
	return {{ $rec }}
}

{{ range $_, $e := $n.Edges }}
{{ $builder := $e.Type.QueryName }}
// Query{{ pascal $e.Name }} queries the {{ $e.Name }} edge of a {{ $n.Name }}.
func (c *{{ $client }}) Query{{ pascal $e.Name }}({{ $rec }} *{{ $n.Name }}) *{{ $builder }} {
	query := &{{ $builder }}{config: c.config}
	query.path = func(ctx context.Context) (fromV {{ $.Storage.Builder }}, _ error) {
		{{- with extend $n "Receiver" $rec "Edge" $e "Ident" "fromV" }}
			{{ $tmpl := printf "dialect/%s/query/from" $.Storage }}
			{{- xtemplate $tmpl . -}}
		{{- end -}}
		return fromV, nil
	}
	return query
}
{{ end }}

// Hooks returns the client hooks.
func (c *{{ $client }}) Hooks() []Hook {
	{{- if or $n.NumHooks $n.HasPolicy }}
		hooks := c.hooks.{{ $n.Name }}
		return append(hooks[:len(hooks):len(hooks)], {{ $n.Package }}.Hooks[:]...)
	{{- else }}
		return c.hooks.{{ $n.Name }}
	{{- end }}
}

{{ end }}
{{ end }}

{{/* A template that can be overrided in order to add additional fields to the client.*/}}
{{ define "client/fields/additional" }}{{ end }}