package provider

import (
	"bufio"
	"encoding/json"
	"fmt"
	"io"
	"orchestra/internal/domain"
)

type Sink interface{ Append(domain.Event) error }
type Provider interface {
	Ingest(io.Reader, Sink) (int, error)
}

// JSONL treats each line as an external task object. Replaying the same input
// is safe because the store deduplicates the stable source/external_id key.
type JSONL struct{}

func (JSONL) Ingest(r io.Reader, sink Sink) (int, error) {
	sc := bufio.NewScanner(r)
	count := 0
	line := 0
	for sc.Scan() {
		line++
		raw := sc.Bytes()
		if len(raw) == 0 {
			continue
		}
		var p map[string]any
		if err := json.Unmarshal(raw, &p); err != nil {
			return count, fmt.Errorf("line %d: %w", line, err)
		}
		if err := domain.ValidateCreated(p); err != nil {
			return count, fmt.Errorf("line %d: %w", line, err)
		}
		b, _ := json.Marshal(p)
		e := domain.Event{ID: domain.NewID(), Type: "TaskCreated", TaskID: domain.NewID(), Version: 1, Payload: b}
		if err := sink.Append(e); err != nil {
			return count, fmt.Errorf("line %d: %w", line, err)
		}
		count++
	}
	return count, sc.Err()
}