package main

import (
	"errors"
	"fmt"
	"go/ast"
	"go/printer"
	"go/token"
	"os"

	"github.com/spf13/cobra"

	"git.offline-twitter.com/offline-labs/gas-stack/pkg/codegen/modelgenerate"
	. "git.offline-twitter.com/offline-labs/gas-stack/pkg/flowutils"
	"git.offline-twitter.com/offline-labs/gas-stack/pkg/schema"
)

var ErrNoSuchTable = errors.New("no such table")

var generate_model = &cobra.Command{
	Use:   "generate <model_name>",
	Short: "Generate a model type",

	Args: cobra.ExactArgs(1),

	RunE: func(cmd *cobra.Command, args []string) error {
		path := Must(cmd.Flags().GetString("schema"))
		modname := Must(cmd.Flags().GetString("modname"))
		schema_sql, err := os.ReadFile(path)
		if err != nil {
			return fmt.Errorf("reading path %s: %w", path, err)
		}
		db := schema.InitDB(string(schema_sql))
		tables := schema.SchemaFromDB(db).Tables
		table, isOk := tables[args[0]]
		if !isOk {
			return ErrNoSuchTable
		}

		fset := token.NewFileSet()

		if Must(cmd.Flags().GetBool("test")) {
			file2 := modelgenerate.GenerateModelTestAST(table, modname)
			PanicIf(printer.Fprint(os.Stdout, fset, file2))
		} else {
			file := &ast.File{
				Name: ast.NewIdent("db"), // TODO: parameterize

				Decls: []ast.Decl{
					&ast.GenDecl{
						Tok: token.IMPORT,
						Specs: []ast.Spec{
							&ast.ImportSpec{Path: &ast.BasicLit{Kind: token.STRING, Value: `"database/sql"`}},
							&ast.ImportSpec{Path: &ast.BasicLit{Kind: token.STRING, Value: `"errors"`}},
							&ast.ImportSpec{Path: &ast.BasicLit{Kind: token.STRING, Value: `"fmt"`}},
							&ast.ImportSpec{
								Name: ast.NewIdent("."),
								Path: &ast.BasicLit{Kind: token.STRING, Value: `"git.offline-twitter.com/offline-labs/gas-stack/pkg/db"`},
							},
						},
					},
					modelgenerate.GenerateIDType(table),
					modelgenerate.GenerateModelAST(table),
					modelgenerate.GenerateSaveItemFunc(table),
					modelgenerate.GenerateDeleteItemFunc(table),
					modelgenerate.GenerateSQLFieldsConst(table),
					modelgenerate.GenerateGetItemByIDFunc(table),
				},
			}

			PanicIf(printer.Fprint(os.Stdout, fset, file))
		}

		return nil
	},
}

func init() {
	generate_model.Flags().String("schema", "pkg/db/schema.sql", "Path to SQL schema file")
	generate_model.Flags().String("modname", "mymodule", "Name of project's Go module (TODO: detect automatically)")
	generate_model.Flags().Bool("test", false, "Generate test file instead of regular file")
}