package db

import (
	"encoding/json"
	"encoding/xml"
	"fmt"
	"github.com/pelletier/go-toml/v2"
	"gopkg.in/ini.v1"
	"gopkg.in/yaml.v3"
	"os"
	"strconv"
	"strings"
)

// AppConfig 程序启动配置
type AppConfig struct {
	Name            string            `json:"name,omitempty"             yaml:"name,omitempty"             toml:"name,multiline,omitempty"             xml:"name,omitempty"             ini:"name,omitempty"`            // 应用名称
	Description     string            `json:"description,omitempty"      yaml:"description,omitempty"      toml:"description,multiline,omitempty"      xml:"description,omitempty"      ini:"description,omitempty"`     // 应用描述
	Script          string            `json:"script,omitempty"           yaml:"script,omitempty"           toml:"script,multiline,omitempty"           xml:"script,omitempty"           ini:"script,omitempty"`          // 执行脚本
	Args            []string          `json:"args,omitempty"             yaml:"args,omitempty"             toml:"args,multiline,omitempty"             xml:"args,omitempty"             ini:"args,omitempty"`            // 启动参数
	Stdin           string            `json:"stdin,omitempty"            yaml:"stdin,omitempty"            toml:"stdin,multiline,omitempty"            xml:"stdin,omitempty"            ini:"stdin,omitempty"`           // 标准输入数据
	Cwd             string            `json:"Cwd,omitempty"              yaml:"Cwd,omitempty"              toml:"Cwd,multiline,omitempty"              xml:"Cwd,omitempty"              ini:"cwd,omitempty"`             // 工作目录
	Env             map[string]string `json:"env,omitempty"              yaml:"env,omitempty"              toml:"env,multiline,omitempty"              xml:"env,omitempty"              ini:"env,omitempty"`             // 自定义环境变量
	Interpreter     string            `json:"interpreter,omitempty"      yaml:"interpreter,omitempty"      toml:"interpreter,multiline,omitempty"      xml:"interpreter,omitempty"      ini:"interpreter,omitempty"`     // 脚本解释程序
	InterpreterArgs []string          `json:"interpreter_args,omitempty" yaml:"interpreter_args,omitempty" toml:"interpreter_args,multiline,omitempty" xml:"interpreter_args,omitempty" ini:"interpreterArgs,omitempty"` // 解释程序参数
	RerunOnError    *RerunOnError     `json:"rerunOnError"               yaml:"rerunOnError,omitempty"     toml:"rerunOnError,multiline,omitempty"     xml:"rerunOnError,omitempty"     ini:"rerunOnError,omitempty"`    // 错误重启策略
	Custom          map[string]any    `json:"custom,omitempty"           yaml:"custom,omitempty"           toml:"custom,multiline,omitempty"           xml:"custom,omitempty"           ini:"custom,omitempty"`          // 其它自定义参数
}

type Unmarshaller func(data []byte, v any) error

func ParseInput(input string) ([]*App, error) {
	var configs []AppConfig
	var err error
	var app *App

	if IsAppID(input) {
		var id int
		if id, err = strconv.Atoi(input); err != nil {
			return nil, fmt.Errorf("invalid identifier")
		}
		app, err = FindApp(WithAppID(uint(id)))
	} else if strings.HasSuffix(input, ".pmt.json") {
		configs, err = Unmarshal(input, json.Unmarshal)
	} else if strings.HasSuffix(input, ".pmt.toml") {
		configs, err = Unmarshal(input, toml.Unmarshal)
	} else if strings.HasSuffix(input, ".pmt.yaml") {
		configs, err = Unmarshal(input, yaml.Unmarshal)
	} else if strings.HasSuffix(input, ".pmt.xml") {
		configs, err = Unmarshal(input, xml.Unmarshal)
	} else if strings.HasSuffix(input, ".pmt.ini") {
		configs, err = Unmarshal(input, func(data []byte, v any) error {
			if info, err := ini.Load(data); err != nil {
				return err
			} else {
				return info.MapTo(v)
			}
		})
	} else if file, ex := os.Stat(input); ex == nil {
		if file.IsDir() {
			return nil, fmt.Errorf("unsupported directoty entry")
		}

		if app, err = scriptToApp(input); err != nil {
			return nil, err
		}
	} else {
		app, err = FindApp(WithAppName(input))
	}
	if err != nil {
		return nil, err
	}
	if app != nil {
		return []*App{app}, nil
	}
	if len(configs) == 0 {
		return nil, fmt.Errorf("not found")
	}
	var apps []*App
	for _, cfg := range configs {
		apps = append(apps, optionsToApp(&cfg))
	}
	return apps, err
}

func scriptToApp(script string) (*App, error) {
	name := ToSnakeCase(script)
	app, err := FindApp(WithAppName(name))
	if err == nil {
		if app.Script != script {
			return nil, fmt.Errorf("应用 %s 已存在", script)
		}
		return app, nil
	}
	return &App{
		PID:    -1,
		Name:   name,
		Script: script,
	}, nil
}

func optionsToApp(opts *AppConfig) *App {
	return &App{
		PID:             -1,
		Name:            opts.Name,
		Description:     opts.Description,
		Script:          opts.Script,
		Command:         nil,
		Arguments:       opts.Args,
		Stdin:           opts.Stdin,
		Cwd:             opts.Cwd,
		Environments:    opts.Env,
		Interpreter:     opts.Interpreter,
		InterpreterArgs: opts.InterpreterArgs,
		RerunOnError:    opts.RerunOnError,
		Options:         opts.Custom,
	}
}

// Unmarshal 读取配置文件
func Unmarshal(file string, unmarshal Unmarshaller) ([]AppConfig, error) {
	bts, err := os.ReadFile(file)
	if err != nil {
		return nil, err
	}

	var config AppConfig
	if err = unmarshal(bts, &config); err == nil {
		return []AppConfig{config}, nil
	}

	var configs []AppConfig
	if unmarshal(bts, &configs) == nil {
		return configs, nil
	}

	return nil, err
}