package dart

import (
	"net/http"
	"strings"
)

type Group struct {
	prefix      string
	middlewares []Middleware
	parent      *Group
	dart        *Dart
}

func (g *Group) Group(prefix string) *Group {
	return &Group{
		prefix: prefix,
		parent: g,
		dart:   g.dart,
	}
}

func (g *Group) Static(prefix, root string, middlewares ...Middleware) {
	fileServer := http.FileServer(http.Dir(root))
	fullPath := joinPaths(g.getFullPrefix(), prefix)
	g.register(http.MethodGet, prefix+"/*filepath", func(ctx *Context) error {
		http.StripPrefix(fullPath, fileServer).ServeHTTP(ctx.response, ctx.request)
		return nil
	})
}

func (g *Group) Use(middlewares ...Middleware) {
	g.middlewares = append(g.middlewares, middlewares...)
}

func (g *Group) GET(path string, h Handler, middlewares ...Middleware) {
	g.register(http.MethodGet, path, h, middlewares...)
}

func (g *Group) POST(path string, h Handler, middlewares ...Middleware) {
	g.register(http.MethodPost, path, h, middlewares...)
}

func (g *Group) PUT(path string, h Handler, middlewares ...Middleware) {
	g.register(http.MethodPut, path, h, middlewares...)
}

func (g *Group) DELETE(path string, h Handler, middlewares ...Middleware) {
	g.register(http.MethodDelete, path, h, middlewares...)
}

func (g *Group) PATCH(path string, h Handler, middlewares ...Middleware) {
	g.register(http.MethodPatch, path, h, middlewares...)
}

func (g *Group) HEAD(path string, h Handler, middlewares ...Middleware) {
	g.register(http.MethodHead, path, h, middlewares...)
}

func (g *Group) OPTIONS(path string, h Handler, middlewares ...Middleware) {
	g.register(http.MethodOptions, path, h, middlewares...)
}

func (g *Group) getFullPrefix() string {
	if g.parent != nil {
		return joinPaths(g.parent.getFullPrefix(), g.prefix)
	}
	return g.prefix
}

func (g *Group) getAllMiddlewares() []Middleware {
	middlewares := make([]Middleware, 0)
	current := g

	for current != nil {
		middlewares = append(current.middlewares, middlewares...)
		current = current.parent
	}
	return middlewares
}

func (g *Group) register(method string, path string, h Handler, middlewares ...Middleware) {
	fullPath := joinPaths(g.getFullPrefix(), path)
	allMiddlewares := append(g.getAllMiddlewares(), middlewares...)
	g.dart.register(method, fullPath, h, allMiddlewares...)
}

func joinPaths(a, b string) string {
	a = strings.TrimSuffix(a, "/")
	b = strings.TrimPrefix(b, "/")

	if b == "" {
		return a
	}

	return a + "/" + b
}