package main

import (
	"encoding/json"
	"fmt"
	"io"
	"os"
	"path/filepath"
	"strings"
)

type VsServerConfigOptions struct {
	Version         string `json:"Version"`
	ServerName      string `json:"ServerName"`
	Port            int    `json:"Port"`
	IpAddress       string `json:"IpAddress"`
	MaxClients      int    `json:"MaxClients"`
	Password        string `json:"Password"`
	DefaultRole     string `json:"DefaultRole"`
	GuestRole       string `json:"GuestRole"`
	PreApprovedRole string `json:"PreApprovedRole"`
}

func PrepareInstanceConfig(templateVersion string, instanceConfigPath string, options VsServerConfigOptions, cfg *AppConfig) error {
	return SyncInstanceConfig(templateVersion, instanceConfigPath, options, cfg)
}

func SyncInstanceConfig(templateVersion string, instanceConfigPath string, options VsServerConfigOptions, cfg *AppConfig) error {
	templatePath := filepath.Join(cfg.Storage.ConfigTemplatesDir, templateVersion, "serverconfig.json")

	if _, err := os.Stat(instanceConfigPath); os.IsNotExist(err) {
		if err := os.MkdirAll(filepath.Dir(instanceConfigPath), 0755); err != nil {
			return fmt.Errorf("failed creating instance directory tree: %w", err)
		}

		source, err := os.Open(templatePath)
		if err != nil {
			return fmt.Errorf("failed opening baseline template file: %w", err)
		}
		defer source.Close()

		destination, err := os.Create(instanceConfigPath)
		if err != nil {
			return fmt.Errorf("failed creating target instance configuration: %w", err)
		}

		_, err = io.Copy(destination, source)
		destination.Close()
		if err != nil {
			return fmt.Errorf("failed cloning configuration template payload: %w", err)
		}
	}

	data, err := os.ReadFile(instanceConfigPath)
	if err != nil {
		return fmt.Errorf("failed reading configuration data: %w", err)
	}

	var rawConfig map[string]interface{}
	if err := json.Unmarshal(data, &rawConfig); err != nil {
		return fmt.Errorf("failed parsing configuration JSON payload: %w", err)
	}

	rawConfig["ServerName"] = options.ServerName
	rawConfig["Port"] = options.Port
	rawConfig["MaxClients"] = options.MaxClients

	if options.Password != "" {
		rawConfig["Password"] = options.Password
	} else {
		rawConfig["Password"] = nil
	}

	instanceDir := filepath.Dir(instanceConfigPath)
	if worldConfig, ok := rawConfig["WorldConfig"].(map[string]interface{}); ok {
		worldConfig["SaveFileLocation"] = filepath.Join(instanceDir, "Saves", "default.vcdbs")
	}

	if modPaths, ok := rawConfig["ModPaths"].([]interface{}); ok {
		for i, pathVal := range modPaths {
			if strPath, ok := pathVal.(string); ok && (strings.Contains(strPath, "/vs-manager/instances/") || filepath.IsAbs(strPath)) && strPath != "Mods" {
				modPaths[i] = filepath.Join(instanceDir, "Mods")
			}
		}
	}

	updatedData, err := json.MarshalIndent(rawConfig, "", "  ")
	if err != nil {
		return fmt.Errorf("failed marshaling updated configuration adjustments: %w", err)
	}

	return os.WriteFile(instanceConfigPath, updatedData, 0644)
}