package main

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

	"git.yeij.top/AskaEth/Cyrene_v2/internal/capability/registry"
	"git.yeij.top/AskaEth/Cyrene_v2/internal/channel/adapter"
	"git.yeij.top/AskaEth/Cyrene_v2/internal/config"
	"git.yeij.top/AskaEth/Cyrene_v2/internal/config/runtimeconfig"
	"git.yeij.top/AskaEth/Cyrene_v2/internal/logger"
	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/model"
	"git.yeij.top/AskaEth/Cyrene_v2/internal/services/channelbridge"
	"git.yeij.top/AskaEth/Cyrene_v2/internal/user"
)

// ownerRegistrar implements gateway.OwnerRegistrar: it persists a channel account
// id into the owner whitelist (configs/users/owner.yaml) AND hot-updates the live
// owner profile the channel bridge holds, so a weixin scan-login confirmation is
// recognized as the owner immediately — no restart, no manual edit. path and the
// live profile are captured at wiring time: the boot-loaded *user.OwnerProfile is
// the same pointer the bridge resolves actors against, so RegisterAccount on it is
// visible to ResolveActor without touching the bridge.
type ownerRegistrar struct {
	path  string
	owner *user.OwnerProfile
	log   *slog.Logger
}

func (r *ownerRegistrar) RegisterChannelOwner(_ context.Context, platform, accountID string) error {
	if strings.TrimSpace(accountID) == "" {
		return nil
	}
	if err := user.RegisterOwnerAccount(r.path, platform, accountID); err != nil {
		return fmt.Errorf("register owner %s:%s: %w", platform, accountID, err)
	}
	// Hot-effect: extend the live profile the bridge already points at. If the
	// profile failed to load at boot (r.owner nil) the persist above still lands
	// on disk and is recognized after a restart; log so the operator knows the
	// hot path was unavailable.
	if r.owner != nil {
		r.owner.RegisterAccount(platform, accountID)
	} else {
		r.log.Warn("owner registrar: no live profile, whitelist persisted to disk only (restart to take effect)",
			"platform", platform, "accountId", accountID)
	}
	r.log.Info("owner whitelist registered", "platform", platform, "accountId", accountID)
	return nil
}

// wireChannels constructs the four IM channel adapters from environment
// configuration, registers them so the admin API can enumerate them, and wires
// them into the channel bridge so a configured adapter connects and routes
// inbound messages through session→actor→loop→reply. Adapters without
// credentials stay disconnected (logged, never fatal): connecting with an empty
// config would either fail or, for weixin-ilink, trigger a blocking scan-code
// login.
func (a *app) wireChannels() error {
	// The channel config is runtime-editable: channels.json (when present and
	// valid) is authoritative, otherwise the env channel block is the fallback
	// (design/04 §3.1). The factory and the store read the same file so a panel
	// save + hot-reload keeps boot and runtime consistent.
	channelsPath := runtimeconfig.DefaultChannelsPath(resolveDataDir(a.cfg))
	factory := &channelFactory{path: channelsPath, fallback: channelAccountsFromEnv(), log: a.log}
	adapters := buildChannelAdapters(factory)
	for _, ch := range adapters {
		capp := registry.Capability{
			Name:        ch.Name(),
			Kind:        registry.KindChannel,
			Description: ch.Name(),
			Value:       ch,
		}
		if err := a.caps.Register(capp); err != nil {
			a.log.Warn("channel register skipped", "channel", ch.Name(), "error", err)
		}
	}

	bridge, berr := channelbridge.New(channelbridge.Options{
		Log:            logger.WithSource(a.log, "services/channelbridge"),
		Loop:           a.loop,
		Sessions:       a.sessions,
		Owner:          a.owner,
		History:        a.history,
		QuietStartHour: a.cfg.Background.QuietStartHour,
		QuietEndHour:   a.cfg.Background.QuietEndHour,
		// Optional review model prunes low-value queued messages near the per-adapter
		// cap (design/12 §6 策略四). Nil adapter → the gate falls back to FIFO evict.
		Review: reviewFor(a.modelAdapter, logger.WithSource(a.log, "services/channelbridge/review")),
		// Light is the design/18 §3 participation judge: a cost-controlled light LLM
		// decision on a triggered group/stranger message (role-name mention / probability
		// / active window). Only an actual trigger feeds the group context.
		Light:         engageLightFor(a.modelAdapter, logger.WithSource(a.log, "services/channelbridge/engage")),
		TriggerWords:  a.defaultTriggerWords(),
		PersonaPrompt: a.defaultInstructions(),
		Engage:        channelbridge.DefaultEngageConfig(),
		// EngageFor is left nil (P2a); per-group overrides arrive with P2c.
		// Factory lets the panel save hot-replace a platform's adapters without a
		// restart (design/04 §3.1).
		Factory: factory,
		// ChannelPersona resolves an account's channel-level role from the same
		// config the factory builds from (design/22 §2 方案 b); the bridge caches it
		// per connected adapter and refreshes it on every reload.
		ChannelPersona: factory.Persona,
	})
	if berr != nil {
		return fmt.Errorf("channel bridge: %w", berr)
	}
	for _, ch := range adapters {
		bridge.Add(ch)
	}
	bridge.Start()
	a.channelBridge = bridge
	a.channels = &runtimeChannels{path: channelsPath, fallback: factory.fallback, bridge: bridge, log: a.log}
	a.log.Info("channel adapters registered", "count", len(adapters))
	return nil
}

// runtimeChannels is the gateway-facing view of the runtime-editable channel
// config. Load re-reads channels.json (file wins → env fallback) and Reload
// delegates to the bridge's hot-replace, so the panel's save/reload path drives
// the same source the bridge boots from.
type runtimeChannels struct {
	path     string
	fallback map[string][]config.ChannelAccount
	bridge   *channelbridge.Bridge
	log      *slog.Logger
}

func (r *runtimeChannels) Path() string { return r.path }

func (r *runtimeChannels) Load() map[string][]config.ChannelAccount {
	accounts, warn := runtimeconfig.LoadChannels(r.path, r.fallback)
	if warn != nil {
		r.log.Warn("channels.json load fell back to env", "error", warn)
	}
	return accounts
}

func (r *runtimeChannels) Reload(platform string) error { return r.bridge.Reload(platform) }

// reviewFor builds the channel-bridge review model (design/12 §6 策略四), or nil
// when no model adapter is available so the gate falls back to FIFO eviction — the
// reviewer is never invoked with a nil adapter (which would panic on .Chat).
func reviewFor(llm model.Adapter, log *slog.Logger) adapter.Reviewer {
	if llm == nil {
		return nil
	}
	return channelbridge.NewLLMReviewer(llm, log)
}

// engageLightFor builds the design/18 §3 participation judge, or nil when no model
// adapter is available so the bridge's participation engine fails closed toward
// silence (a triggered message without a judge is never answered).
func engageLightFor(llm model.Adapter, log *slog.Logger) channelbridge.LightJudge {
	if llm == nil {
		return nil
	}
	return channelbridge.NewLLMLightJudge(llm, log)
}

// defaultTriggerWords returns the default persona's role-name reminder words
// (design/18 §2) so the channel bridge knows which group messages cause a PROBING.
func (a *app) defaultTriggerWords() []string {
	if c, ok := a.personas.DefaultCharacter(); ok {
		if p, ok := a.personas.Persona(c.PersonaID); ok {
			return append([]string(nil), p.TriggerWords...)
		}
	}
	return nil
}