package daemon

import (
	"context"
	"fmt"
	"io"
	"log/slog"
	"strings"
	"time"

	"banger/internal/model"
)

func newDaemonLogger(w io.Writer, rawLevel string) (*slog.Logger, string, error) {
	level, normalized, err := parseLogLevel(rawLevel)
	if err != nil {
		return nil, "", err
	}
	logger := slog.New(slog.NewJSONHandler(w, &slog.HandlerOptions{Level: level}))
	return logger, normalized, nil
}

func parseLogLevel(raw string) (slog.Level, string, error) {
	switch strings.ToLower(strings.TrimSpace(raw)) {
	case "", "info":
		return slog.LevelInfo, "info", nil
	case "debug":
		return slog.LevelDebug, "debug", nil
	case "warn", "warning":
		return slog.LevelWarn, "warn", nil
	case "error":
		return slog.LevelError, "error", nil
	default:
		return 0, "", fmt.Errorf("unsupported log_level %q (use debug, info, warn, or error)", raw)
	}
}

func (d *Daemon) beginOperation(name string, attrs ...any) operationLog {
	if d.logger != nil {
		d.logger.Info("operation started", append([]any{"operation", name}, attrs...)...)
	}
	return operationLog{
		logger:  d.logger,
		name:    name,
		started: time.Now(),
		attrs:   append([]any(nil), attrs...),
	}
}

type operationLog struct {
	logger  *slog.Logger
	name    string
	started time.Time
	attrs   []any
}

func (o operationLog) stage(stage string, attrs ...any) {
	o.log(slog.LevelInfo, "operation stage", append([]any{"stage", stage}, attrs...)...)
}

func (o operationLog) debugStage(stage string, attrs ...any) {
	o.log(slog.LevelDebug, "operation stage", append([]any{"stage", stage}, attrs...)...)
}

func (o operationLog) done(attrs ...any) {
	o.log(slog.LevelInfo, "operation completed", append([]any{"duration_ms", time.Since(o.started).Milliseconds()}, attrs...)...)
}

func (o operationLog) fail(err error, attrs ...any) error {
	if err == nil {
		return nil
	}
	o.log(slog.LevelError, "operation failed", append([]any{"duration_ms", time.Since(o.started).Milliseconds(), "error", err.Error()}, attrs...)...)
	return err
}

func (o operationLog) log(level slog.Level, msg string, attrs ...any) {
	if o.logger == nil {
		return
	}
	base := append([]any{"operation", o.name}, o.attrs...)
	base = append(base, attrs...)
	o.logger.Log(context.Background(), level, msg, base...)
}

func vmLogAttrs(vm model.VMRecord) []any {
	attrs := []any{
		"vm_id", vm.ID,
		"vm_name", vm.Name,
		"image_id", vm.ImageID,
	}
	if vm.Runtime.GuestIP != "" {
		attrs = append(attrs, "guest_ip", vm.Runtime.GuestIP)
	}
	if vm.Runtime.TapDevice != "" {
		attrs = append(attrs, "tap_device", vm.Runtime.TapDevice)
	}
	if vm.Runtime.APISockPath != "" {
		attrs = append(attrs, "api_socket", vm.Runtime.APISockPath)
	}
	if vm.Runtime.PID > 0 {
		attrs = append(attrs, "pid", vm.Runtime.PID)
	}
	if vm.Runtime.LogPath != "" {
		attrs = append(attrs, "log_path", vm.Runtime.LogPath)
	}
	return attrs
}

func imageLogAttrs(image model.Image) []any {
	attrs := []any{
		"image_id", image.ID,
		"image_name", image.Name,
	}
	if image.ArtifactDir != "" {
		attrs = append(attrs, "artifact_dir", image.ArtifactDir)
	}
	if image.RootfsPath != "" {
		attrs = append(attrs, "rootfs_path", image.RootfsPath)
	}
	return attrs
}

func annotateLogPath(err error, path string) error {
	if err == nil || strings.TrimSpace(path) == "" {
		return err
	}
	return fmt.Errorf("%w; inspect %s", err, path)
}