package resource

import (
	"context"
	"errors"
	"io"
	"net/http"
	"os"
	"time"

	mihomoHttp "github.com/metacubex/mihomo/component/http"
	"github.com/metacubex/mihomo/component/profile/cachefile"
	types "github.com/metacubex/mihomo/constant/provider"
)

type FileVehicle struct {
	path string
}

func (f *FileVehicle) Type() types.VehicleType {
	return types.File
}

func (f *FileVehicle) Path() string {
	return f.path
}

func (f *FileVehicle) Url() string {
	return "file://" + f.path
}

func (f *FileVehicle) Read(ctx context.Context, oldHash types.HashType) (buf []byte, hash types.HashType, err error) {
	buf, err = os.ReadFile(f.path)
	if err != nil {
		return
	}
	hash = types.MakeHash(buf)
	return
}

func (f *FileVehicle) Proxy() string {
	return ""
}

func NewFileVehicle(path string) *FileVehicle {
	return &FileVehicle{path: path}
}

type HTTPVehicle struct {
	url    string
	path   string
	proxy  string
	header http.Header
}

func (h *HTTPVehicle) Url() string {
	return h.url
}

func (h *HTTPVehicle) Type() types.VehicleType {
	return types.HTTP
}

func (h *HTTPVehicle) Path() string {
	return h.path
}

func (h *HTTPVehicle) Proxy() string {
	return h.proxy
}

func (h *HTTPVehicle) Read(ctx context.Context, oldHash types.HashType) (buf []byte, hash types.HashType, err error) {
	ctx, cancel := context.WithTimeout(ctx, time.Second*20)
	defer cancel()
	header := h.header
	setIfNoneMatch := false
	if oldHash.IsValid() {
		hashBytes, etag := cachefile.Cache().GetETagWithHash(h.url)
		if oldHash.EqualBytes(hashBytes) && etag != "" {
			if header == nil {
				header = http.Header{}
			} else {
				header = header.Clone()
			}
			header.Set("If-None-Match", etag)
			setIfNoneMatch = true
		}
	}
	resp, err := mihomoHttp.HttpRequestWithProxy(ctx, h.url, http.MethodGet, header, nil, h.proxy)
	if err != nil {
		return
	}
	defer resp.Body.Close()
	if resp.StatusCode < 200 || resp.StatusCode > 299 {
		if setIfNoneMatch && resp.StatusCode == http.StatusNotModified {
			return nil, oldHash, nil
		}
		err = errors.New(resp.Status)
		return
	}
	buf, err = io.ReadAll(resp.Body)
	if err != nil {
		return
	}
	hash = types.MakeHash(buf)
	cachefile.Cache().SetETagWithHash(h.url, hash.Bytes(), resp.Header.Get("ETag"))
	return
}

func NewHTTPVehicle(url string, path string, proxy string, header http.Header) *HTTPVehicle {
	return &HTTPVehicle{
		url:    url,
		path:   path,
		proxy:  proxy,
		header: header,
	}
}