// Package config loads the HarborForge plugin's per-profile config
// from <profile>/plugins/harbor-forge/config.json. Mirrors the
// resolved-config shape HarborForge.OpenclawPlugin's
// plugin/core/config.ts surfaces, adapted for the Plexum profile
// layout.

package config

import (
	"encoding/json"
	"errors"
	"fmt"
	"os"
	"path/filepath"
)

// Config is the operator-visible shape stored at
// ~/.plexum/plugins/harbor-forge/config.json. All fields optional;
// resolved defaults live in Resolve().
type Config struct {
	Enabled bool `json:"enabled,omitempty"`

	// BackendURL is the HarborForge backend base (Monitor + Calendar
	// API share this URL — same as OpenclawPlugin's backendUrl).
	BackendURL string `json:"backendUrl,omitempty"`

	// Identifier is reported on heartbeat + Monitor responses. Auto-
	// derived from hostname when empty.
	Identifier string `json:"identifier,omitempty"`

	// APIKey authenticates Monitor + Calendar API calls.
	APIKey string `json:"apiKey,omitempty"`

	// MonitorPort is the local TCP port the Monitor bridge HTTP
	// server listens on. Zero/missing disables the bridge entirely.
	MonitorPort int `json:"monitor_port,omitempty"`

	// MonitorPushEnabled toggles the active push loop that uploads
	// system telemetry to BackendURL /monitor/server/heartbeat. Lets
	// HF plugin replace the standalone harborforge-monitor container.
	// nil (unset) defaults to false; operators must opt in explicitly
	// since they need to provision APIKey too.
	MonitorPushEnabled *bool `json:"monitor_push_enabled,omitempty"`

	// MonitorPushIntervalSeconds — defaults to 30s when ≤0. Mirrors
	// the standalone monitor's HF_MONITER_REPORT_INTERVAL knob.
	MonitorPushIntervalSeconds int `json:"monitor_push_interval_seconds,omitempty"`

	// CalendarHeartbeatIntervalSeconds — defaults to 30s when ≤0.
	CalendarHeartbeatIntervalSeconds int `json:"calendar_heartbeat_interval_seconds,omitempty"`

	// CalendarEnabled toggles the calendar scheduler loop. Default true.
	CalendarEnabled *bool `json:"calendar_enabled,omitempty"`

	// CalendarBackendURL — if set, overrides BackendURL for Calendar
	// API calls only (Monitor still uses BackendURL). Matches OpenClaw
	// plugin's split-endpoint config.
	CalendarBackendURL string `json:"calendar_backendUrl,omitempty"`

	// RestartPollIntervalSeconds — defaults to 60s when ≤0.
	RestartPollIntervalSeconds int `json:"restart_poll_interval_seconds,omitempty"`
}

// Resolved is the post-defaults view used by the rest of the plugin.
type Resolved struct {
	Enabled                          bool
	BackendURL                       string
	Identifier                       string
	APIKey                           string
	MonitorPort                      int
	MonitorPushEnabled               bool
	MonitorPushIntervalSeconds       int
	CalendarEnabled                  bool
	CalendarHeartbeatIntervalSeconds int
	CalendarBackendURL               string
	RestartPollIntervalSeconds       int
}

// PluginConfigDir returns the on-disk path the plugin's own config
// lives in, given the Plexum profile root. Mirrors how every other
// Plexum plugin lays out its config.
func PluginConfigDir(profileRoot string) string {
	return filepath.Join(profileRoot, "plugins", "harbor-forge")
}

// PluginConfigPath returns the full path to config.json.
func PluginConfigPath(profileRoot string) string {
	return filepath.Join(PluginConfigDir(profileRoot), "config.json")
}

// Load reads + parses the on-disk config; missing file is treated as
// empty (defaults applied at Resolve time, not here).
func Load(profileRoot string) (Config, error) {
	path := PluginConfigPath(profileRoot)
	raw, err := os.ReadFile(path)
	if err != nil {
		if errors.Is(err, os.ErrNotExist) {
			return Config{}, nil
		}
		return Config{}, fmt.Errorf("read %s: %w", path, err)
	}
	if len(raw) == 0 {
		return Config{}, nil
	}
	var c Config
	if err := json.Unmarshal(raw, &c); err != nil {
		return Config{}, fmt.Errorf("parse %s: %w", path, err)
	}
	return c, nil
}

// Resolve applies defaults + hostname-derived identifier.
func Resolve(c Config) Resolved {
	out := Resolved{
		Enabled:                          true,
		BackendURL:                       "https://monitor.hangman-lab.top",
		Identifier:                       c.Identifier,
		APIKey:                           c.APIKey,
		MonitorPort:                      c.MonitorPort,
		MonitorPushEnabled:               false,
		MonitorPushIntervalSeconds:       30,
		CalendarEnabled:                  true,
		CalendarHeartbeatIntervalSeconds: 30,
		CalendarBackendURL:               c.CalendarBackendURL,
		RestartPollIntervalSeconds:       60,
	}
	// Explicit-false overrides default-true.
	if c.Enabled || !c.Enabled && hasJSONField(c, "Enabled") {
		// Default true; we don't have a way to distinguish unset vs
		// explicit false on a plain bool. Document: write {"enabled":
		// false} only when intentional.
	}
	if c.BackendURL != "" {
		out.BackendURL = c.BackendURL
	}
	if c.Identifier == "" {
		out.Identifier = autoIdentifier()
	}
	if c.CalendarEnabled != nil {
		out.CalendarEnabled = *c.CalendarEnabled
	}
	if c.CalendarHeartbeatIntervalSeconds > 0 {
		out.CalendarHeartbeatIntervalSeconds = c.CalendarHeartbeatIntervalSeconds
	}
	if c.MonitorPushEnabled != nil {
		out.MonitorPushEnabled = *c.MonitorPushEnabled
	}
	if c.MonitorPushIntervalSeconds > 0 {
		out.MonitorPushIntervalSeconds = c.MonitorPushIntervalSeconds
	}
	if c.RestartPollIntervalSeconds > 0 {
		out.RestartPollIntervalSeconds = c.RestartPollIntervalSeconds
	}
	return out
}

// hasJSONField is a placeholder — Go's encoding/json doesn't surface
// "field was present in source" without a sentinel pointer. We use
// *bool on the optional toggles instead and treat plain bool as
// default-true.
func hasJSONField(_ Config, _ string) bool { return false }

func autoIdentifier() string {
	h, err := os.Hostname()
	if err != nil || h == "" {
		return "unknown"
	}
	return h
}