package skill

import (
    "fmt"
    "os"
    "path/filepath"
    "strings"
)

type Manager struct {
    skills []*Skill
    dirs   []string
}

func NewManager(dir string) *Manager {
    dirs := []string{}
    if dir != "" {
        dirs = append(dirs, dir)
    } else {
        if home, err := os.UserHomeDir(); err == nil {
            dirs = append(dirs, filepath.Join(home, ".config", "ai-agent", "skills"))
        }
    }
    return &Manager{dirs: dirs}
}

func (m *Manager) AddSearchPath(dir string) {
    for _, d := range m.dirs {
        if d == dir {
            return
        }
    }
    m.dirs = append(m.dirs, dir)
}

func (m *Manager) Names() []string {
    var names []string
    for _, s := range m.skills {
        names = append(names, s.Name)
    }
    return names
}

func (m *Manager) LoadAll() error {
    for _, dir := range m.dirs {
        if err := m.loadFromDir(dir); err != nil {
            return err
        }
    }
    return nil
}

func (m *Manager) loadFromDir(dir string) error {
    if dir == "" {
        return nil
    }
    entries, err := os.ReadDir(dir)
    if err != nil {
        if os.IsNotExist(err) {
            return nil
        }
        return fmt.Errorf("read skills dir: %w", err)
    }
    for _, entry := range entries {
        if entry.IsDir() || !strings.HasSuffix(entry.Name(), ".md") {
            continue
        }
        path := filepath.Join(dir, entry.Name())
        data, err := os.ReadFile(path)
        if err != nil {
            continue
        }
        skill, err := parseFrontmatter(string(data))
        if err != nil {
            continue
        }
        skill.Path = path
        if skill.Name == "" {
            skill.Name = strings.TrimSuffix(entry.Name(), ".md")
        }
        m.skills = append(m.skills, skill)
    }
    return nil
}

func (m *Manager) All() []*Skill {
    return m.skills
}

func (m *Manager) Activate(name string) error {
    for _, s := range m.skills {
        if s.Name == name {
            s.Active = true
            return nil
        }
    }
    return fmt.Errorf("skill not found: %s", name)
}

func (m *Manager) Deactivate(name string) error {
    for _, s := range m.skills {
        if s.Name == name {
            s.Active = false
            return nil
        }
    }
    return fmt.Errorf("skill not found: %s", name)
}

func (m *Manager) ActiveContent() string {
    var parts []string
    for _, s := range m.skills {
        if s.Active && s.Content != "" {
            parts = append(parts, fmt.Sprintf("### %s\n%s", s.Name, s.Content))
        }
    }
    return strings.Join(parts, "\n\n")
}