// Copyright 2024 Matthew Rich <matthewrich.conf@gmail.com>. All rights reserved.

package transport

import (
	"errors"
_	"fmt"
	"net/url"
	"net/http"
_	"strings"
_	"path/filepath"
	"io"
	"io/fs"
_	"os"
	"context"
)

var (
	ErrTransportResourceAbsent error = errors.New("Transport resource is absent")
)

type Handler interface {
	URI() *url.URL
	ContentType() string
	SetGzip(bool)
	DetectGzip()
	Gzip() bool
	Signature() string
	Stat() (fs.FileInfo, error)
}

type HandlerReader interface {
	Reader() io.ReadCloser
}

type HandlerWriter interface {
	Writer() io.WriteCloser
}

type Reader struct {
	uri *url.URL
	handle Handler
	stream io.ReadCloser
	exists func() bool
}

func NewReader(u *url.URL) (reader *Reader, e error) {
	return NewReaderWithContext(u, context.Background())
}

func NewReaderWithContext(u *url.URL, ctx context.Context) (reader *Reader, e error) {
	reader = &Reader{ uri: u }
	switch u.Scheme {
	case "http", "https":
		reader.handle, e = NewHTTPReader(u, ctx)
	case "file":
		fallthrough
	default:
		reader.handle, e = NewFileReader(u)
		reader.exists = func() bool { return FileExists(u) }
	}
	reader.SetStream(reader.handle.(HandlerReader).Reader())
	return
}

func NewReaderURI(uri string) (reader *Reader, e error) {
	var u *url.URL
	if u, e = url.Parse(uri); e == nil {
		return NewReader(u)
	}
	return
}

type Writer struct {
	uri *url.URL
	handle Handler
	stream io.WriteCloser
	exists func() bool
}

func NewWriter(u *url.URL) (writer *Writer, e error) {
	return NewWriterWithContext(u, context.Background())
}

func NewWriterWithContext(u *url.URL, ctx context.Context) (writer *Writer, e error) {
	writer = &Writer{ uri: u }

	switch u.Scheme {
	case "http", "https":
		writer.handle, e = NewHTTPWriter(u, ctx)
	case "file":
		fallthrough
	default:
		writer.handle, e = NewFileWriter(u)
		writer.exists = func() bool { return FileExists(u) }
	}

	writer.SetStream(writer.handle.(HandlerWriter).Writer())
	return writer, e
}

func NewWriterURI(uri string) (writer *Writer, e error) {
	var u *url.URL
	if u, e = url.Parse(uri); e == nil {
		return NewWriter(u)
	}
	return
}

func ExistsURI(uri string) bool {
	if u, e := url.Parse(uri); e == nil {
		return Exists(u)
	}
	return false
}

func Exists(u *url.URL) bool {
	switch u.Scheme {
	case "http", "https":
		return HTTPExists(u)
	case "file":
		fallthrough
	default:
		return FileExists(u)
	}
}

func (r *Reader) Exists() bool { return r.exists() }

func (r *Reader) Read(b []byte) (int, error) {
	return r.stream.Read(b)
}

func (r *Reader) Close() error {
	return r.stream.Close()
}

func (r *Reader) ContentType() string {
	return r.handle.ContentType()
}

func (r *Reader) SetGzip(value bool) {
	r.handle.SetGzip(value)
}

func (r *Reader) DetectGzip() { r.handle.DetectGzip() }

func (r *Reader) Gzip() bool {
	return r.handle.Gzip()
}

func (r *Reader) Stat() (info fs.FileInfo, err error) {
	return r.handle.Stat()
}

func (r *Reader) Signature() string {
	return r.handle.Signature()
}

func (r *Reader) SetStream(s io.ReadCloser) {
	r.stream = s
}

func (r *Reader) AddHeader(name string, value string) {
	r.handle.(*HTTPReader).GetRequest().Header.Add(name, value)
}

func (r *Reader) Status() string {
	if httpReader, ok := r.handle.(*HTTPReader); ok {
		return httpReader.GetResponse().Status
	}
	panic("Unable to get HTTP status from reader")
}

func (r *Reader) StatusCode() int {
	if httpReader, ok := r.handle.(*HTTPReader); ok {
		return httpReader.GetResponse().StatusCode
	}
	panic("Unable to get HTTP status code from reader")
}

func (r *Reader) Response() *http.Response {
	return r.handle.(*HTTPReader).GetResponse()
}

func (w *Writer) Exists() bool { return w.exists() }

func (w *Writer) Write(b []byte) (int, error) {
	return w.stream.Write(b)
}

func (w *Writer) ReadFrom(r io.Reader) (n int64, e error) {
	if v, ok := w.stream.(io.ReaderFrom); ok {
		return v.ReadFrom(r)
	} else {
		panic("io.ReaderFrom interface not supported by writer")
	}
}

func (w *Writer) Close() error {
	return w.stream.Close()
}

func (w *Writer) ContentType() string {
	return w.handle.ContentType()
}

func (w *Writer) SetGzip(value bool) {
	w.handle.SetGzip(value)
}

func (w *Writer) DetectGzip() { w.handle.DetectGzip() }

func (w *Writer) Gzip() bool {
	return w.handle.Gzip()
}

func (w *Writer) Signature() string {
	return w.handle.Signature()
}

func (w *Writer) SetStream(s io.WriteCloser) {
	w.stream = s
}

func (w *Writer) AddHeader(name string, value string) {
	w.handle.(*HTTPWriter).PostRequest().Header.Add(name, value)
}

func (w *Writer) Status() string {
	return w.handle.(*HTTPWriter).PostResponse().Status
}

func (w *Writer) StatusCode() int {
	return w.handle.(*HTTPWriter).PostResponse().StatusCode
}

func (w *Writer) Response() *http.Response {
	return w.handle.(*HTTPWriter).PostResponse()
}