package cmd

import (
	"fmt"
	"go/ast"
	"go/parser"
	"go/token"
	"io/fs"
	"log"
	"os"
	"path/filepath"
	"regexp"
	"strings"

	"git.ipao.vip/rogeecn/atomctl/pkg/utils/gomod"
	"github.com/iancoleman/strcase"
	"github.com/pkg/errors"
	"github.com/samber/lo"
	"github.com/spf13/cobra"
)

func CommandGenRoute(root *cobra.Command) {
	cmd := &cobra.Command{
		Use:   "route",
		Short: "generate routes",
		RunE:  commandGenRouteE,
	}

	root.AddCommand(cmd)
}

func commandGenRouteE(cmd *cobra.Command, args []string) error {
	var err error
	var path string
	if len(args) > 0 {
		path = args[0]
	} else {
		path, err = os.Getwd()
		if err != nil {
			return err
		}
	}

	path, _ = filepath.Abs(path)

	err = gomod.Parse(filepath.Join(path, "go.mod"))
	if err != nil {
		return err
	}

	routes := []RouteDefinition{}

	modulePath := filepath.Join(path, "modules")
	if _, err := os.Stat(modulePath); os.IsNotExist(err) {
		log.Fatal("modules dir not exist, ", modulePath)
	}

	filepath.WalkDir(modulePath, func(path string, d fs.DirEntry, err error) error {
		if d.IsDir() {
			return nil
		}
		if !strings.HasSuffix(path, "_controller.go") {
			return nil
		}
		if !strings.HasSuffix(path, ".go") {
			return nil
		}

		routes = append(routes, astParseRoutes(path)...)
		return nil
	})

	routeGroups := lo.GroupBy(routes, func(item RouteDefinition) string {
		return filepath.Dir(item.Path)
	})

	for key, routes := range routeGroups {
		routePath := filepath.Join(key, "routes.gen.go")

		imports := lo.FlatMap(routes, func(item RouteDefinition, index int) []string {
			return lo.Map(item.Imports, func(item string, index int) string {
				return fmt.Sprintf("\t%s", item)
			})
		})

		pkgName := filepath.Base(key)

		f, err := os.OpenFile(routePath, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0o644)
		if err != nil {
			fmt.Printf("ERR: %s %s\n", err, routePath)
			continue
		}
		defer f.Close()

		_, _ = f.WriteString("// Code generated by the atomctl; DO NOT EDIT.\n\n")
		_, _ = f.WriteString("package " + pkgName + "\n\n")
		_, _ = f.WriteString("import (\n")
		_, _ = f.WriteString(strings.Join(imports, "\n"))
		_, _ = f.WriteString("\n")
		_, _ = f.WriteString("\n")

		_, _ = f.WriteString("\t\"github.com/atom-providers/log\"\n")
		_, _ = f.WriteString("\t\"git.ipao.vip/rogeecn/atom/contracts\"\n")
		_, _ = f.WriteString("\t\"github.com/gofiber/fiber/v3\"\n")
		_, _ = f.WriteString("\t. \"github.com/pkg/f\"\n")
		_, _ = f.WriteString(")\n\n")

		_, _ = f.WriteString("// @provider contracts.HttpRoute atom.GroupRoutes\n")
		_, _ = f.WriteString("type Routes struct {\n")
		_, _ = f.WriteString("\tengine\t*fiber.App `inject:\"false\"`\n")
		_, _ = f.WriteString("\tsvc\tcontracts.HttpService\n")
		// inject controllers
		for _, route := range routes {
			_, _ = f.WriteString(fmt.Sprintf("\t%s *%s", strcase.ToLowerCamel(route.Name), route.Name))
		}
		_, _ = f.WriteString("\n}\n\n")

		_, _ = f.WriteString("func (r *Routes) Prepare() error {\n")
		_, _ = f.WriteString("\tlog.Infof(\"register route group: " + pkgName + "\")\n")
		_, _ = f.WriteString("\tr.engine = r.svc.GetEngine().(*fiber.App)\n")

		for _, route := range routes {
			funcName := fmt.Sprintf(`register%sRoutes()`, route.Name)
			_, _ = f.WriteString(fmt.Sprintf("\tr.%s\n", funcName))
		}
		_, _ = f.WriteString("\treturn nil\n")
		_, _ = f.WriteString("}\n\n")

		for _, route := range routes {
			funcName := fmt.Sprintf(`func (r *Routes)register%sRoutes()`, route.Name)
			_, _ = f.WriteString(fmt.Sprintf(`%s{`, funcName))
			_, _ = f.WriteString("\n")

			for _, action := range route.Actions {
				_, _ = f.WriteString("\t")
				_, _ = f.WriteString(fmt.Sprintf("r.engine.%s(%q, ", strcase.ToCamel(strings.ToLower(action.Method)), formatRoute(action.Route)))

				if action.HasData {
					_, _ = f.WriteString("Data")
				}
				_, _ = f.WriteString("Func")

				paramsSize := len(action.Params)
				if paramsSize >= 1 {
					_, _ = f.WriteString(fmt.Sprintf("%d", paramsSize))
				}

				paramsStrings := []string{fmt.Sprintf("r.%s.%s", strcase.ToLowerCamel(route.Name), action.Name)}
				for _, p := range action.Params {
					var paramString string
					switch p.Position {
					case PositionPath:
						paramString = fmt.Sprintf(`Path[%s](%q)`, p.Type, p.Name)
					case PositionURI:
						paramString = fmt.Sprintf(`URI[%s]()`, p.Type)
					case PositionQuery:
						paramString = fmt.Sprintf(`Query[%s]()`, p.Type)
					case PositionBody:
						paramString = fmt.Sprintf(`Body[%s]()`, p.Type)
					case PositionHeader:
						paramString = fmt.Sprintf(`Header[%s]()`, p.Type)
					case PositionCookie:
						paramString = fmt.Sprintf(`Cookie[%s]()`, p.Type)
					}

					paramsStrings = append(paramsStrings, paramString)
				}
				_, _ = f.WriteString("(" + strings.Join(paramsStrings, ", ") + ")")

				_, _ = f.WriteString(")\n")
			}

			_, _ = f.WriteString("}\n")
		}
	}

	return nil
}

type RouteDefinition struct {
	Path    string
	Name    string
	Imports []string
	Actions []ActionDefinition
}

type ParamDefinition struct {
	Name     string
	Type     string
	Position Position
}

type ActionDefinition struct {
	Route   string
	Method  string
	Name    string
	HasData bool
	Params  []ParamDefinition
}
type Position string

const (
	PositionPath   Position = "Path"
	PositionURI    Position = "Uri"
	PositionQuery  Position = "Query"
	PositionBody   Position = "Body"
	PositionHeader Position = "Header"
	PositionCookie Position = "Cookie"
)

func astParseRoutes(source string) []RouteDefinition {
	if strings.HasSuffix(source, "_test.go") {
		return []RouteDefinition{}
	}

	if strings.HasSuffix(source, "/provider.go") {
		return []RouteDefinition{}
	}

	fset := token.NewFileSet()
	node, err := parser.ParseFile(fset, source, nil, parser.ParseComments)
	if err != nil {
		log.Println("ERR: ", err)
		return nil
	}

	imports := make(map[string]string)
	for _, imp := range node.Imports {
		paths := strings.Split(strings.Trim(imp.Path.Value, "\""), "/")
		name := paths[len(paths)-1]
		pkg := imp.Path.Value
		if imp.Name != nil {
			name = imp.Name.Name
			pkg = fmt.Sprintf("%s %q", name, imp.Path.Value)
		}
		imports[name] = pkg
	}

	routes := make(map[string]RouteDefinition)
	actions := make(map[string][]ActionDefinition)
	usedImports := make(map[string][]string)

	// 再去遍历 struct 的方法去
	for _, decl := range node.Decls {
		decl, ok := decl.(*ast.FuncDecl)
		if !ok {
			continue
		}

		// 普通方法不要
		if decl.Recv == nil {
			continue
		}

		recvType := decl.Recv.List[0].Type.(*ast.StarExpr).X.(*ast.Ident).Name
		if _, ok := routes[recvType]; !ok {
			routes[recvType] = RouteDefinition{
				Name:    recvType,
				Path:    source,
				Actions: []ActionDefinition{},
			}
			actions[recvType] = []ActionDefinition{}
		}

		// Doc 中把 @Router 的定义拿出来， Route 格式为 /user/:id [get] 两部分，表示路径和请求方法
		var path, method string
		var err error
		if decl.Doc != nil {
			for _, line := range decl.Doc.List {
				lineText := strings.TrimSpace(line.Text)
				lineText = strings.TrimLeft(lineText, "/ \t")
				if !strings.HasPrefix(lineText, "@Route") {
					continue
				}

				path, method, err = parseRouteComment(lineText)
				if err != nil {
					log.Fatal(errors.Wrapf(err, "file: %s, action: %s", source, decl.Name.Name))
				}
				break
			}
		}
		if path == "" || method == "" {
			log.Printf("[WARN] failed to get router ,file: %s, action: %s", source, decl.Name.Name)
			continue
		}

		// 拿参数列表去, 忽略 context.Context 参数
		params := []ParamDefinition{}
		for _, param := range decl.Type.Params.List {
			// paramsType, ok := param.Type.(*ast.SelectorExpr)

			var typ string
			switch param.Type.(type) {
			case *ast.Ident:
				typ = param.Type.(*ast.Ident).Name
			case *ast.StarExpr:
				paramsType := param.Type.(*ast.StarExpr)
				switch paramsType.X.(type) {
				case *ast.SelectorExpr:
					X := paramsType.X.(*ast.SelectorExpr)
					typ = fmt.Sprintf("*%s.%s", X.X.(*ast.Ident).Name, X.Sel.Name)
				default:
					typ = fmt.Sprintf("*%s", paramsType.X.(*ast.Ident).Name)
				}
			case *ast.SelectorExpr:
				typ = fmt.Sprintf("%s.%s", param.Type.(*ast.SelectorExpr).X.(*ast.Ident).Name, param.Type.(*ast.SelectorExpr).Sel.Name)
			}

			if strings.HasSuffix(typ, "Context") || strings.HasSuffix(typ, "Ctx") {
				continue
			}
			pkgName := strings.Split(strings.Trim(typ, "*"), ".")
			if len(pkgName) == 2 {
				usedImports[recvType] = append(usedImports[recvType], imports[pkgName[0]])
			}

			position := PositionPath
			if strings.HasSuffix(typ, string(PositionQuery)) || strings.HasSuffix(typ, "QueryFilter") {
				position = PositionQuery
			}
			if strings.HasSuffix(typ, string(PositionBody)) || strings.HasSuffix(typ, "Form") {
				position = PositionBody
			}
			if strings.HasSuffix(typ, string(PositionHeader)) {
				position = PositionHeader
			}
			typ = strings.TrimPrefix(typ, "*")

			for _, name := range param.Names {
				params = append(params, ParamDefinition{
					Name:     name.Name,
					Type:     typ,
					Position: position,
				})
			}
		}

		actions[recvType] = append(actions[recvType], ActionDefinition{
			Route:   path,
			Method:  strings.ToUpper(method),
			Name:    decl.Name.Name,
			HasData: len(decl.Type.Results.List) > 1,
			Params:  params,
		})
	}

	var items []RouteDefinition
	for k, item := range routes {
		a, ok := actions[k]
		if !ok {
			continue
		}
		item.Actions = a
		item.Imports = []string{}
		if im, ok := usedImports[k]; ok {
			item.Imports = lo.Uniq(im)
		}
		items = append(items, item)
	}
	return items
}

func parseRouteComment(line string) (string, string, error) {
	pattern := regexp.MustCompile(`(?mi)@router\s+(.*?)\s+\[(.*?)\]`)
	submatch := pattern.FindStringSubmatch(line)

	if len(submatch) != 3 {
		return "", "", errors.New("invalid route definition")
	}

	return submatch[1], submatch[2], nil
}

func getPackageRoute(mod, path string) string {
	paths := strings.SplitN(path, "modules", 2)
	pkg := paths[1]
	// path可能值为
	// /test/user_controller.go
	// /test/modules/user_controller.go

	return strings.TrimLeft(filepath.Dir(pkg), "/")
}

func formatRoute(route string) string {
	pattern := regexp.MustCompile(`(?mi)\{(.*?)\}`)
	if !pattern.MatchString(route) {
		return route
	}

	items := pattern.FindAllStringSubmatch(route, -1)
	for _, item := range items {
		param := strcase.ToLowerCamel(item[1])
		route = strings.ReplaceAll(route, item[0], fmt.Sprintf("{%s}", param))
	}

	route = pattern.ReplaceAllString(route, ":$1")
	route = strings.ReplaceAll(route, "/:id", "/:id<int>")
	route = strings.ReplaceAll(route, "Id/", "Id<int>/")
	return route
}