feat: implement filesystem scanner

1 files changed, 106 insertions, 0 deletions

diff --git a/internal/probe/probe.go b/internal/probe/probe.go
index 2cc7dc8..7f5b887 100644
--- a/internal/probe/probe.go
+++ b/internal/probe/probe.go
@@ -1,2 +1,108 @@
 // Package probe implements media metadata probing.
 package probe
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"os/exec"
+	"strconv"
+
+	"github.com/paul/kiss-media-player/internal/model"
+)
+
+// Prober extracts metadata from a media file.
+type Prober interface {
+	Probe(ctx context.Context, path string) (*model.Metadata, error)
+}
+
+// FFProber wraps the ffprobe command-line tool.
+type FFProber struct{}
+
+// NewFFProber creates a new FFProber.
+func NewFFProber() *FFProber {
+	return &FFProber{}
+}
+
+// Probe runs ffprobe against the given path and parses the resulting JSON.
+func (f *FFProber) Probe(ctx context.Context, path string) (*model.Metadata, error) {
+	cmd := exec.CommandContext(ctx, "ffprobe",
+		"-v", "error",
+		"-show_format",
+		"-show_streams",
+		"-of", "json",
+		path,
+	)
+	out, err := cmd.Output()
+	if err != nil {
+		if exitErr, ok := err.(*exec.ExitError); ok && len(exitErr.Stderr) > 0 {
+			return nil, fmt.Errorf("ffprobe %s: %w: %s", path, err, string(exitErr.Stderr))
+		}
+		return nil, fmt.Errorf("ffprobe %s: %w", path, err)
+	}
+	return parseFFprobeOutput(out)
+}
+
+type ffprobeOutput struct {
+	Format struct {
+		Duration string `json:"duration"`
+		BitRate  string `json:"bit_rate"`
+	} `json:"format"`
+	Streams []struct {
+		CodecName string `json:"codec_name"`
+		Width     int    `json:"width"`
+		Height    int    `json:"height"`
+		CodecType string `json:"codec_type"`
+	} `json:"streams"`
+}
+
+func parseFFprobeOutput(data []byte) (*model.Metadata, error) {
+	var out ffprobeOutput
+	if err := json.Unmarshal(data, &out); err != nil {
+		return nil, fmt.Errorf("unmarshal ffprobe output: %w", err)
+	}
+
+	meta := &model.Metadata{}
+	if out.Format.Duration != "" {
+		if d, err := strconv.ParseFloat(out.Format.Duration, 64); err == nil {
+			meta.Duration = d
+		}
+	}
+	if out.Format.BitRate != "" {
+		if b, err := strconv.Atoi(out.Format.BitRate); err == nil {
+			meta.Bitrate = b
+		}
+	}
+
+	for _, s := range out.Streams {
+		if s.CodecType == "video" {
+			if meta.Codec == "" {
+				meta.Codec = s.CodecName
+			}
+			if s.Width > 0 && s.Height > 0 {
+				meta.Resolution = fmt.Sprintf("%dx%d", s.Width, s.Height)
+			}
+			break
+		}
+	}
+
+	// Fallback to first stream codec if no video stream found.
+	if meta.Codec == "" && len(out.Streams) > 0 {
+		meta.Codec = out.Streams[0].CodecName
+	}
+
+	return meta, nil
+}
+
+// MockProber is a test fake for Prober.
+type MockProber struct {
+	ProbeFunc func(ctx context.Context, path string) (*model.Metadata, error)
+}
+
+// Probe delegates to ProbeFunc or returns zero-value metadata.
+func (m *MockProber) Probe(ctx context.Context, path string) (*model.Metadata, error) {
+	if m.ProbeFunc != nil {
+		return m.ProbeFunc(ctx, path)
+	}
+	return &model.Metadata{}, nil
+}