package envelope

import (
	"bytes"
	"crypto/sha256"
	"io"

	"smesh.lol/pkg/nostr/filter"
	"smesh.lol/pkg/nostr/hex"
	"smesh.lol/pkg/nostr/ints"
	"smesh.lol/pkg/nostr/text"
	"smesh.lol/pkg/lol/chk"
	"smesh.lol/pkg/lol/errorf"
)

// Close — client request to terminate a subscription.

const CloseLabel = "CLOSE"

type Close struct{ ID []byte }

func (en *Close) Label() string { return CloseLabel }
func (en *Close) Write(w io.Writer) (err error) {
	_, err = w.Write(en.Marshal(nil))
	return
}
func (en *Close) Marshal(dst []byte) (b []byte) {
	b = dst
	b = Marshal(b, CloseLabel, func(bst []byte) (o []byte) {
		o = bst
		o = append(o, '"')
		o = append(o, en.ID...)
		o = append(o, '"')
		return
	})
	return
}
func (en *Close) Unmarshal(b []byte) (r []byte, err error) {
	r = b
	if en.ID, r, err = text.UnmarshalQuoted(r); chk.E(err) {
		return
	}
	r, err = SkipToTheEnd(r)
	return
}

// EOSE — End Of Stored Events signal.

const EOSELabel = "EOSE"

type EOSE struct{ Subscription []byte }

func (en *EOSE) Label() string { return EOSELabel }
func (en *EOSE) Write(w io.Writer) (err error) {
	_, err = w.Write(en.Marshal(nil))
	return
}
func (en *EOSE) Marshal(dst []byte) (b []byte) {
	b = dst
	b = Marshal(b, EOSELabel, func(bst []byte) (o []byte) {
		o = bst
		o = append(o, '"')
		o = append(o, en.Subscription...)
		o = append(o, '"')
		return
	})
	return
}
func (en *EOSE) Unmarshal(b []byte) (r []byte, err error) {
	r = b
	if en.Subscription, r, err = text.UnmarshalQuoted(r); chk.E(err) {
		return
	}
	r, err = SkipToTheEnd(r)
	return
}

// OK — acknowledgement for EVENT submission.

const OKLabel = "OK"

type OK struct {
	EventID []byte
	OK      bool
	Reason  []byte
}

func (en *OK) Label() string { return OKLabel }
func (en *OK) Write(w io.Writer) (err error) {
	_, err = w.Write(en.Marshal(nil))
	return
}
func (en *OK) Marshal(dst []byte) (b []byte) {
	b = dst
	b = Marshal(b, OKLabel, func(bst []byte) (o []byte) {
		o = bst
		o = append(o, '"')
		o = hex.EncAppend(o, en.EventID)
		o = append(o, '"', ',')
		o = text.MarshalBool(o, en.OK)
		o = append(o, ',', '"')
		o = text.NostrEscape(o, en.Reason)
		o = append(o, '"')
		return
	})
	return
}
func (en *OK) Unmarshal(b []byte) (r []byte, err error) {
	r = b
	var idBytes []byte
	if idBytes, r, err = text.UnmarshalHex(r); err != nil {
		return
	}
	if len(idBytes) != sha256.Size {
		err = errorf.E([]byte("invalid size for event id, require %d got %d"),
			sha256.Size, len(idBytes))
		return
	}
	en.EventID = idBytes
	if r, err = text.Comma(r); chk.E(err) {
		return
	}
	if r, en.OK, err = text.UnmarshalBool(r); chk.E(err) {
		return
	}
	if r, err = text.Comma(r); chk.E(err) {
		return
	}
	if en.Reason, r, err = text.UnmarshalQuoted(r); chk.E(err) {
		return
	}
	r, err = SkipToTheEnd(r)
	return
}

// Notice — relay message to user.

const NoticeLabel = "NOTICE"

type Notice struct{ Message []byte }

func (en *Notice) Label() string { return NoticeLabel }
func (en *Notice) Write(w io.Writer) (err error) {
	_, err = w.Write(en.Marshal(nil))
	return
}
func (en *Notice) Marshal(dst []byte) (b []byte) {
	b = dst
	b = Marshal(b, NoticeLabel, func(bst []byte) (o []byte) {
		o = bst
		o = append(o, '"')
		o = text.NostrEscape(o, en.Message)
		o = append(o, '"')
		return
	})
	return
}
func (en *Notice) Unmarshal(b []byte) (r []byte, err error) {
	r = b
	if en.Message, r, err = text.UnmarshalQuoted(r); chk.E(err) {
		return
	}
	r, err = SkipToTheEnd(r)
	return
}

// Closed — relay-side subscription termination.

const ClosedLabel = "CLOSED"

type Closed struct {
	Subscription []byte
	Reason       []byte
}

func (en *Closed) Label() string { return ClosedLabel }
func (en *Closed) Write(w io.Writer) (err error) {
	_, err = w.Write(en.Marshal(nil))
	return
}
func (en *Closed) Marshal(dst []byte) (b []byte) {
	b = dst
	b = Marshal(b, ClosedLabel, func(bst []byte) (o []byte) {
		o = bst
		o = append(o, '"')
		o = append(o, en.Subscription...)
		o = append(o, '"', ',', '"')
		o = text.NostrEscape(o, en.Reason)
		o = append(o, '"')
		return
	})
	return
}
func (en *Closed) Unmarshal(b []byte) (r []byte, err error) {
	r = b
	if en.Subscription, r, err = text.UnmarshalQuoted(r); chk.E(err) {
		return
	}
	if en.Reason, r, err = text.UnmarshalQuoted(r); chk.E(err) {
		return
	}
	r, err = SkipToTheEnd(r)
	return
}

// Count — COUNT request/response.

const CountLabel = "COUNT"

type CountRequest struct {
	Subscription []byte
	Filters      filter.S
}

func (en *CountRequest) Label() string { return CountLabel }
func (en *CountRequest) Write(w io.Writer) (err error) {
	_, err = w.Write(en.Marshal(nil))
	return
}
func (en *CountRequest) Marshal(dst []byte) (b []byte) {
	b = dst
	b = Marshal(b, CountLabel, func(bst []byte) (o []byte) {
		o = bst
		o = append(o, '"')
		o = append(o, en.Subscription...)
		o = append(o, '"')
		for _, f := range en.Filters {
			o = append(o, ',')
			o = f.Marshal(o)
		}
		return
	})
	return
}
func (en *CountRequest) Unmarshal(b []byte) (r []byte, err error) {
	r = b
	if en.Subscription, r, err = text.UnmarshalQuoted(r); chk.E(err) {
		return
	}
	if r, err = en.Filters.Unmarshal(r); chk.E(err) {
		return
	}
	r, err = SkipToTheEnd(r)
	return
}

type CountResponse struct {
	Subscription []byte
	Count        int
	Approximate  bool
}

func (en *CountResponse) Label() string { return CountLabel }
func (en *CountResponse) Write(w io.Writer) (err error) {
	_, err = w.Write(en.Marshal(nil))
	return
}
func (en *CountResponse) Marshal(dst []byte) (b []byte) {
	b = dst
	b = Marshal(b, CountLabel, func(bst []byte) (o []byte) {
		o = bst
		o = append(o, '"')
		o = append(o, en.Subscription...)
		o = append(o, '"', ',')
		o = ints.New(en.Count).Marshal(o)
		if en.Approximate {
			o = append(o, ',')
			o = append(o, "true"...)
		}
		return
	})
	return
}
func (en *CountResponse) Unmarshal(b []byte) (r []byte, err error) {
	r = b
	if en.Subscription, r, err = text.UnmarshalQuoted(r); chk.E(err) {
		return
	}
	if r, err = text.Comma(r); chk.E(err) {
		return
	}
	i := ints.New(0)
	if r, err = i.Unmarshal(r); chk.E(err) {
		return
	}
	en.Count = int(i.N)
	if len(r) > 0 && r[0] == ',' {
		r = r[1:]
		if bytes.HasPrefix(r, []byte("true")) {
			en.Approximate = true
		}
	}
	r, err = SkipToTheEnd(r)
	return
}