package err113

import (
	"go/ast"
	"go/types"
	"strings"

	"golang.org/x/tools/go/analysis"
)

var methods2check = map[string]map[string]func(*ast.CallExpr, *types.Info) bool{ // nolint: gochecknoglobals
	"errors": {"New": justTrue},
	"fmt":    {"Errorf": checkWrap},
}

func justTrue(*ast.CallExpr, *types.Info) bool {
	return true
}

func checkWrap(ce *ast.CallExpr, info *types.Info) bool {
	return !(len(ce.Args) > 0 && strings.Contains(toString(ce.Args[0], info), `%w`))
}

func inspectDefinition(pass *analysis.Pass, tlds map[*ast.CallExpr]struct{}, n ast.Node) bool { //nolint: unparam
	// check whether the call expression matches time.Now().Sub()
	ce, ok := n.(*ast.CallExpr)
	if !ok {
		return true
	}

	if _, ok = tlds[ce]; ok {
		return true
	}

	fn, ok := ce.Fun.(*ast.SelectorExpr)
	if !ok {
		return true
	}

	fxName, ok := asImportedName(fn.X, pass.TypesInfo)
	if !ok {
		return true
	}

	methods, ok := methods2check[fxName]
	if !ok {
		return true
	}

	checkFunc, ok := methods[fn.Sel.Name]
	if !ok {
		return true
	}

	if !checkFunc(ce, pass.TypesInfo) {
		return true
	}

	pass.Reportf(
		ce.Pos(),
		"do not define dynamic errors, use wrapped static errors instead: %q",
		render(pass.Fset, ce),
	)

	return true
}

func toString(ex ast.Expr, info *types.Info) string {
	if tv, ok := info.Types[ex]; ok && tv.Value != nil {
		return tv.Value.ExactString()
	}

	return ""
}