package main

import (
	"bytes"
	"fmt"
	"io/ioutil"
	"os"
	"strings"
	"text/template"
)

type readInfo struct {
	baseType   string
	targetType string
	path       string
}

var readFuncs = map[string][]*readInfo{
	"scopes": {
		{
			baseType:   "Scope",
			targetType: "Scope",
			path:       "scopes",
		},
	},
	"authtokens": {
		{
			baseType:   "AuthToken",
			targetType: "AuthToken",
			path:       "auth-tokens",
		},
	},
	"groups": {
		{
			baseType:   "Group",
			targetType: "Group",
			path:       "groups",
		},
	},
	"users": {
		{
			baseType:   "User",
			targetType: "User",
			path:       "users",
		},
	},
	"roles": {
		{
			baseType:   "Role",
			targetType: "Role",
			path:       "roles",
		},
	},
	"hosts": {
		{
			baseType:   "HostCatalog",
			targetType: "HostCatalog",
			path:       "host-catalogs",
		},
	},
}

func writeReadFuncs() {
	for outPkg, funcs := range readFuncs {
		outFile := os.Getenv("GEN_BASEPATH") + fmt.Sprintf("/api/%s/read.gen.go", outPkg)
		outBuf := bytes.NewBuffer([]byte(fmt.Sprintf(
			`// Code generated by "make api"; DO NOT EDIT.
package %s
`, outPkg)))
		for _, readInfo := range funcs {
			readFuncTemplate.Execute(outBuf, struct {
				BaseType   string
				TargetType string
				TargetName string
				Path       string
			}{
				BaseType:   readInfo.baseType,
				TargetType: readInfo.targetType,
				TargetName: strings.Split(readInfo.targetType, ".")[strings.Count(readInfo.targetType, ".")],
				Path:       readInfo.path,
			})
		}
		if err := ioutil.WriteFile(outFile, outBuf.Bytes(), 0644); err != nil {
			fmt.Printf("error writing file %q: %v\n", outFile, err)
			os.Exit(1)
		}
	}
}

var readFuncTemplate = template.Must(template.New("").Parse(
	`
func (s {{ .BaseType }}) Read{{ .TargetName }}(ctx context.Context, id string) (*{{ .TargetType }}, *api.Error, error) {
	if id == "" {
		return nil, nil, fmt.Errorf("empty ID value passed into Read{{ .TargetName }} request")
	}
	
	if s.Client == nil {
		return nil, nil, fmt.Errorf("nil client in Read{{ .TargetName }} request")
	}
	
	var opts []api.Option
	if s.Scope.Id != "" {
		// If it's explicitly set here, override anything that might be in the
		// client
		opts = append(opts, api.WithScopeId(s.Scope.Id))
	}

	req, err := s.Client.NewRequest(ctx, "GET", fmt.Sprintf("%s/%s", "{{ .Path }}", id), nil, opts...)
	if err != nil {
		return nil, nil, fmt.Errorf("error creating Read{{ .TargetName }} request: %w", err)
	}

	resp, err := s.Client.Do(req)
	if err != nil {
		return nil, nil, fmt.Errorf("error performing client request during Read{{ .TargetName }} call: %w", err)
	}

	target := new({{ .TargetType }})
	apiErr, err := resp.Decode(target)
	if err != nil {
		return nil, nil, fmt.Errorf("error decoding Read{{ .TargetName }} repsonse: %w", err)
	}

	{{ if (eq .TargetType "Scope") }}
	target.Client = s.Client.Clone()
	target.Client.SetScopeId(target.Id)
	{{ else }}
	target.Client = s.Client
	{{ end }}

	return target, apiErr, nil
}
`))