package factory

import (
	"fmt"
	"io"
	"net/http"
	"os"
	"path/filepath"
	"strings"
	"time"

	"aoiprxkit"
	"github.com/jan/fm-rds-tx/internal/config"
	"github.com/jan/fm-rds-tx/internal/ingest"
	"github.com/jan/fm-rds-tx/internal/ingest/adapters/aoip"
	"github.com/jan/fm-rds-tx/internal/ingest/adapters/httpraw"
	"github.com/jan/fm-rds-tx/internal/ingest/adapters/icecast"
	"github.com/jan/fm-rds-tx/internal/ingest/adapters/srt"
	"github.com/jan/fm-rds-tx/internal/ingest/adapters/stdinpcm"
)

type Deps struct {
	Stdin                io.Reader
	HTTP                 *http.Client
	SRTOpener            aoiprxkit.SRTConnOpener
	AES67ReceiverFactory aoip.ReceiverFactory
}

type AudioIngress interface {
	WritePCM16(data []byte) (int, error)
}

func BuildSource(cfg config.Config, deps Deps) (ingest.Source, AudioIngress, error) {
	switch normalizeIngestKind(cfg.Ingest.Kind) {
	case "", "none":
		return nil, nil, nil
	case "stdin", "stdin-pcm":
		reader := deps.Stdin
		if reader == nil {
			reader = os.Stdin
		}
		src := stdinpcm.New("stdin-main", reader, cfg.Ingest.Stdin.SampleRateHz, cfg.Ingest.Stdin.Channels, 1024)
		return src, nil, nil
	case "http-raw":
		src := httpraw.New("http-raw-main", cfg.Ingest.HTTPRaw.SampleRateHz, cfg.Ingest.HTTPRaw.Channels)
		return src, src, nil
	case "icecast":
		src := icecast.New(
			"icecast-main",
			cfg.Ingest.Icecast.URL,
			deps.HTTP,
			icecast.ReconnectConfig{
				Enabled:          cfg.Ingest.Reconnect.Enabled,
				InitialBackoffMs: cfg.Ingest.Reconnect.InitialBackoffMs,
				MaxBackoffMs:     cfg.Ingest.Reconnect.MaxBackoffMs,
			},
			icecast.WithDecoderPreference(cfg.Ingest.Icecast.Decoder),
		)
		return src, nil, nil
	case "srt":
		srtCfg := aoiprxkit.SRTConfig{
			URL:          cfg.Ingest.SRT.URL,
			Mode:         cfg.Ingest.SRT.Mode,
			SampleRateHz: cfg.Ingest.SRT.SampleRateHz,
			Channels:     cfg.Ingest.SRT.Channels,
		}
		opts := []srt.Option{}
		if deps.SRTOpener != nil {
			opts = append(opts, srt.WithConnOpener(deps.SRTOpener))
		}
		src := srt.New("srt-main", srtCfg, opts...)
		return src, nil, nil
	case "aes67", "aoip", "aoip-rtp":
		aoipCfg, err := buildAES67Config(cfg)
		if err != nil {
			return nil, nil, err
		}
		opts := []aoip.Option{}
		if deps.AES67ReceiverFactory != nil {
			opts = append(opts, aoip.WithReceiverFactory(deps.AES67ReceiverFactory))
		}
		src := aoip.New("aes67-main", aoipCfg, opts...)
		return src, nil, nil
	default:
		return nil, nil, fmt.Errorf("unsupported ingest kind: %s", cfg.Ingest.Kind)
	}
}

func SampleRateForKind(cfg config.Config) int {
	switch normalizeIngestKind(cfg.Ingest.Kind) {
	case "stdin", "stdin-pcm":
		if cfg.Ingest.Stdin.SampleRateHz > 0 {
			return cfg.Ingest.Stdin.SampleRateHz
		}
	case "http-raw":
		if cfg.Ingest.HTTPRaw.SampleRateHz > 0 {
			return cfg.Ingest.HTTPRaw.SampleRateHz
		}
	case "icecast":
		return 44100
	case "srt":
		if cfg.Ingest.SRT.SampleRateHz > 0 {
			return cfg.Ingest.SRT.SampleRateHz
		}
	case "aes67", "aoip", "aoip-rtp":
		if cfg.Ingest.AES67.SampleRateHz > 0 {
			return cfg.Ingest.AES67.SampleRateHz
		}
	}
	return 44100
}

func normalizeIngestKind(kind string) string {
	return strings.ToLower(strings.TrimSpace(kind))
}

func buildAES67Config(cfg config.Config) (aoiprxkit.Config, error) {
	base := aoiprxkit.DefaultConfig()
	ing := cfg.Ingest.AES67
	if strings.TrimSpace(ing.InterfaceName) != "" {
		base.InterfaceName = strings.TrimSpace(ing.InterfaceName)
	}
	if ing.PayloadType >= 0 {
		base.PayloadType = uint8(ing.PayloadType)
	}
	if ing.SampleRateHz > 0 {
		base.SampleRateHz = ing.SampleRateHz
	}
	if ing.Channels > 0 {
		base.Channels = ing.Channels
	}
	if strings.TrimSpace(ing.Encoding) != "" {
		base.Encoding = strings.ToUpper(strings.TrimSpace(ing.Encoding))
	}
	if ing.PacketTimeMs > 0 {
		base.PacketTime = time.Duration(ing.PacketTimeMs) * time.Millisecond
	}
	if ing.JitterDepthPackets > 0 {
		base.JitterDepthPackets = ing.JitterDepthPackets
	}
	if ing.ReadBufferBytes > 0 {
		base.ReadBufferBytes = ing.ReadBufferBytes
	}

	sdpText := strings.TrimSpace(ing.SDP)
	if sdpText == "" && strings.TrimSpace(ing.SDPPath) != "" {
		data, err := os.ReadFile(filepath.Clean(ing.SDPPath))
		if err != nil {
			return aoiprxkit.Config{}, fmt.Errorf("read ingest.aes67.sdpPath: %w", err)
		}
		sdpText = string(data)
	}
	if sdpText != "" {
		info, err := aoiprxkit.ParseMinimalSDP(sdpText)
		if err != nil {
			return aoiprxkit.Config{}, fmt.Errorf("parse ingest.aes67 SDP: %w", err)
		}
		parsed, err := aoiprxkit.ConfigFromSDP(base, info)
		if err != nil {
			return aoiprxkit.Config{}, fmt.Errorf("map ingest.aes67 SDP: %w", err)
		}
		return parsed, nil
	}
	if strings.TrimSpace(ing.MulticastGroup) != "" {
		base.MulticastGroup = strings.TrimSpace(ing.MulticastGroup)
	}
	if ing.Port > 0 {
		base.Port = ing.Port
	}
	if err := base.Validate(); err != nil {
		return aoiprxkit.Config{}, err
	}
	return base, nil
}