// Package service is the ONE capability layer behind both the HTTP API and the
// MCP server (AGENT.md §1.7). HTTP handlers and MCP tool handlers are thin
// adapters that call these methods; Git/forge logic never lives in a handler.
// Everything here goes through the internal/git (and later internal/forge)
// boundaries and obeys the safety rules (§1.4).
package service

import (
	"context"
	"fmt"
	"path/filepath"

	"gitmanager/internal/activity"
	"gitmanager/internal/git"
	"gitmanager/internal/repos"
)

// Service holds the shared dependencies the capabilities need.
type Service struct {
	git   *git.CLI
	index *repos.Index
	feed  *activity.Feed
}

// New builds a Service over the git boundary, the scanner's repo index, and the
// activity feed.
func New(g *git.CLI, index *repos.Index, feed *activity.Feed) *Service {
	return &Service{git: g, index: index, feed: feed}
}

// ListRepos returns a snapshot of every discovered repository.
func (s *Service) ListRepos() []repos.State {
	return s.index.List()
}

// GetRepo returns the cached state for one repo, or false if it is not indexed.
// The path is cleaned so separator style does not defeat the exact-match lookup.
func (s *Service) GetRepo(path string) (repos.State, bool) {
	return s.index.Get(filepath.Clean(path))
}

// RepoDetail returns the enriched detail (branches, commits, remotes) for one
// repo. The second return is false when the path is not an indexed repository —
// we never run git against an arbitrary caller-supplied path (§1.3).
func (s *Service) RepoDetail(ctx context.Context, path string) (repos.Detail, bool) {
	base, ok := s.index.Get(filepath.Clean(path))
	if !ok {
		return repos.Detail{}, false
	}
	return repos.BuildDetail(ctx, s.git, base), true
}

// --- Activity & active project (§8.2) --------------------------------------

// ActiveProject returns the current active project path ("" if none).
func (s *Service) ActiveProject() string {
	return s.feed.ActiveProject()
}

// SetActiveProject makes path the active project (or clears it when empty). It
// rejects a path that is not an indexed repository — the active project must be
// a real repo (§1.3). Returns the recorded event and whether it changed.
func (s *Service) SetActiveProject(actor activity.Actor, path string) (activity.Event, bool, error) {
	if path != "" {
		path = filepath.Clean(path)
		if _, ok := s.index.Get(path); !ok {
			return activity.Event{}, false, fmt.Errorf("unknown repository %q", path)
		}
	}
	ev, changed := s.feed.SetActiveProject(actor, path)
	return ev, changed, nil
}

// RecordActivity appends an arbitrary event to the feed.
func (s *Service) RecordActivity(actor activity.Actor, kind, repo, detail string) activity.Event {
	return s.feed.Record(actor, kind, repo, detail)
}

// Activity returns up to limit recent events, oldest first.
func (s *Service) Activity(limit int) []activity.Event {
	return s.feed.Events(limit)
}

// SubscribeActivity returns a channel of future events plus an unsubscribe func
// the caller must invoke when done.
func (s *Service) SubscribeActivity() (<-chan activity.Event, func()) {
	return s.feed.Subscribe()
}