package skill

import (
    "bufio"
    "strings"

    "gopkg.in/yaml.v3"
)

// Skill represents a loadable skill definition.
type Skill struct {
    Name        string `yaml:"name"`
    Description string `yaml:"description"`
    Active      bool   `yaml:"-"`
    Content     string `yaml:"-"` // markdown body after frontmatter
    Path        string `yaml:"-"` // file path
}

// parseFrontmatter extracts YAML frontmatter and markdown body from a skill file.
// Frontmatter is delimited by "---" on the first and closing lines.
func parseFrontmatter(data string) (*Skill, error) {
    scanner := bufio.NewScanner(strings.NewReader(data))

    // Check for opening "---".
    if !scanner.Scan() || strings.TrimSpace(scanner.Text()) != "---" {
        // No frontmatter — treat entire content as body.
        return &Skill{Content: data}, nil
    }

    // Read YAML lines until closing "---".
    var yamlBuf strings.Builder
    foundEnd := false
    for scanner.Scan() {
        line := scanner.Text()
        if strings.TrimSpace(line) == "---" {
            foundEnd = true
            break
        }
        yamlBuf.WriteString(line)
        yamlBuf.WriteString("\n")
    }

    if !foundEnd {
        // No closing delimiter — treat as body only.
        return &Skill{Content: data}, nil
    }

    // Parse YAML frontmatter.
    s := &Skill{}
    if err := yaml.Unmarshal([]byte(yamlBuf.String()), s); err != nil {
        return nil, err
    }

    // Remaining content is the markdown body.
    var bodyBuf strings.Builder
    for scanner.Scan() {
        if bodyBuf.Len() > 0 {
            bodyBuf.WriteString("\n")
        }
        bodyBuf.WriteString(scanner.Text())
    }
    s.Content = strings.TrimSpace(bodyBuf.String())

    return s, nil
}