package main

import (
	"encoding/json"
	"fmt"
	"log"
	"os"
	"os/exec"
	"strings"
	"text/template"
)

type Protocol struct {
	Types   map[string]map[string]*Type
	Actions map[string]map[string]*Action
}

type Type struct {
	Fields  map[string]*DataType
	Request bool `json:"-"`
	Doc     string
}

type DataType struct {
	List      bool
	Type      string
	Version   string
	FieldName string
	Doc       string
}

type Action struct {
	FnName   string
	Request  string
	Response string
	Doc      string
}

type StructsTemplateInput struct {
	Types          map[string]*Type
	Version        string
	ImportVersions []string
}

type ActionsTemplateInput struct {
	Actions   map[string]*Action
	Version   string
	Responses bool
}

var typeMap = map[string]string{
	"int":     "int32",
	"Integer": "int32",
	"Boolean": "bool",
	"long":    "int64",
	"Long":    "int64",
	"UUID":    "string",
	"boolean": "bool",
	"String":  "string",
	"Map":     "map[string]string", // TODO: make signald print the actual key and value types
}

var fieldNameMap = map[string]string{
	"id":               "ID",
	"recipientGroupId": "RecipientGroupID",
	"uuid":             "UUID",
	"gv1-migration":    "Gv1Migration",
}

func (d *DataType) fixForVersion(field, version string) {
	response, ok := typeMap[d.Type]
	if ok {
		if d.Type == "byte" && d.List {
			d.List = false
		}
		d.Type = response
	} else {
		if d.Version == version || d.Version == "" {
			d.Type = fmt.Sprintf("*%s", d.Type)
		} else {
			d.Type = fmt.Sprintf("*%s.%s", d.Version, d.Type)
		}
	}

	fieldName, ok := fieldNameMap[field]
	if ok {
		d.FieldName = fieldName
	} else {
		components := strings.Split(field, "_")
		for i, c := range components {
			components[i] = strings.Title(c)
		}
		d.FieldName = strings.Join(components, "")
	}
}

func main() {
	var response Protocol
	err := json.NewDecoder(os.Stdin).Decode(&response)
	if err != nil {
		log.Fatal(err, "\nError parsing stdin")
	}

	tmpl, err := template.ParseGlob("tools/generator/*.tmpl")
	if err != nil {
		log.Fatal(err, "\nError parsing templates from tools/generator/*.tmpl")
	}

	for version, actions := range response.Actions {
		inputs := ActionsTemplateInput{Version: version, Responses: false}
		for action, a := range actions {
			actions[action].FnName = strings.Title(action)
			if a.Request != "" {
				response.Types[version][a.Request].Request = true
			}
			if a.Response != "" {
				inputs.Responses = true
			}
			if r, ok := typeMap[a.Response]; ok {
				a.Response = r
			}
		}
		inputs.Actions = actions
		outputDir := fmt.Sprintf("signald/client-protocol/%s", version)
		err = os.MkdirAll(outputDir, os.ModePerm)
		if err != nil {
			log.Fatal("Error creating", outputDir, err)
		}
		outputFilename := fmt.Sprintf("%s/%s", outputDir, "requests.go")
		log.Println("Opening", outputFilename)
		f, err := os.Create(outputFilename)
		if err != nil {
			log.Fatal(err, "\nfailed to open output file ", outputFilename)
		}
		err = tmpl.ExecuteTemplate(f, "requests.go.tmpl", inputs)
		if err != nil {
			log.Fatal(err, "\nfailed to render template")
		}
		err = exec.Command("gofmt", "-w", outputFilename).Run()
		if err != nil {
			log.Fatal(err, " error running gofmt on ", outputFilename)
		}
		fmt.Println(outputFilename)
	}

	for version, types := range response.Types {
		inputs := StructsTemplateInput{Version: version}
		for typeName, t := range types {
			for fieldName, field := range t.Fields {
				types[typeName].Fields[fieldName].fixForVersion(fieldName, version)
				if field.Version != "" && field.Version != version {
					found := false
					for _, v := range inputs.ImportVersions {
						if v == field.Version {
							found = true
							break
						}
					}
					if !found {
						inputs.ImportVersions = append(inputs.ImportVersions, field.Version)
					}
				}
			}
		}
		inputs.Types = types
		outputDir := fmt.Sprintf("signald/client-protocol/%s", version)
		err = os.MkdirAll(outputDir, os.ModePerm)
		if err != nil {
			log.Fatal("Error creating", outputDir, err)
		}
		outputFilename := fmt.Sprintf("%s/%s", outputDir, "structs.go")
		log.Println("Opening", outputFilename)
		f, err := os.Create(outputFilename)
		if err != nil {
			log.Fatal(err, "\nfailed to open output file ", outputFilename)
		}
		err = tmpl.ExecuteTemplate(f, "structs.go.tmpl", inputs)
		if err != nil {
			log.Fatal(err, "\nfailed to render template")
		}
		err = exec.Command("gofmt", "-w", outputFilename).Run()
		if err != nil {
			log.Fatal(err, " error running gofmt on ", outputFilename)
		}
		fmt.Println(outputFilename)
	}
}