package worker

import (
	"encoding/json"
	"fmt"
	"os"
	"path/filepath"

	"gorm.io/driver/sqlite"
	"gorm.io/gorm"
)

type Logger interface {
	Write(line string)
}

type RootConfig struct {
	Data struct {
		Driver string `json:"driver"`
		Path   string `json:"path"`
	} `json:"data"`
	Log struct {
		Path string `json:"log_root_path"`
	} `json:"log"`
}

type Function struct {
	ID           uint `gorm:"primaryKey"`
	FunctionName string
	Version      string
	Path         string
	DeletedAt    gorm.DeletedAt `gorm:"index"`
}

type FuncConfig struct {
	Name    string `json:"name"`
	Version string `json:"version"`
	Entry   string `json:"entry"`
	Runtime string `json:"runtime"`
	Log     struct {
		Output string `json:"output"`
	} `json:"log"`
}

func LoadTreeConfig(root string) (*RootConfig, error) {
	cfgPath := filepath.Join(root, "config.json")
	b, err := os.ReadFile(cfgPath)
	if err != nil {
		return nil, err
	}
	var cfg RootConfig
	if err := json.Unmarshal(b, &cfg); err != nil {
		return nil, err
	}
	return &cfg, nil
}

func OpenDB(cfg *RootConfig, root string) (*gorm.DB, error) {
	switch cfg.Data.Driver {
	case "sqlite":
		dbPath := filepath.Join(root, cfg.Data.Path)
		db, err := gorm.Open(sqlite.Open(dbPath), &gorm.Config{})
		if err != nil {
			return nil, err
		}
		return db, nil
	default:
		return nil, fmt.Errorf("unsupported db driver: %s", cfg.Data.Driver)
	}
}

func FindFunction(db *gorm.DB, name, version string) (*Function, error) {
	var f Function
	if version == "latest" {
		err := db.Where("function_name = ? AND deleted_at IS NULL", name).
			Order("created_at DESC").
			First(&f).Error
		if err != nil {
			return nil, err
		}
	} else {
		if err := db.Where("function_name = ? AND version = ? AND deleted_at IS NULL", name, version).
			First(&f).Error; err != nil {
			return nil, err
		}
	}
	return &f, nil
}

func LoadFunctionConfig(root, funcName, funcPath string) (*FuncConfig, error) {
	cfgFile := filepath.Join(root, funcName, funcPath, "config.json")
	b, err := os.ReadFile(cfgFile)
	if err != nil {
		return nil, err
	}
	var cfg FuncConfig
	if err := json.Unmarshal(b, &cfg); err != nil {
		return nil, err
	}
	return &cfg, nil
}