package collector

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

// Matcher determines if a file should be included in the collection
type Matcher interface {
	ShouldInclude(path string, info os.FileInfo) bool
}

// NameMatcher matches files by exact name
type NameMatcher struct {
	name string
}

// NewNameMatcher creates a matcher for exact filename matching
func NewNameMatcher(name string) *NameMatcher {
	return &NameMatcher{name: name}
}

// ShouldInclude returns true if the file matches the exact name
func (m *NameMatcher) ShouldInclude(path string, info os.FileInfo) bool {
	if info.IsDir() {
		return false
	}
	return info.Name() == m.name
}

// PatternMatcher matches files within directories matching a glob pattern
type PatternMatcher struct {
	pattern         string
	matchedDirs     map[string]bool
	patternSegments []string
}

// NewPatternMatcher creates a matcher for directory pattern matching
func NewPatternMatcher(pattern string) *PatternMatcher {
	// Remove trailing slash if present
	pattern = strings.TrimSuffix(pattern, "/")

	return &PatternMatcher{
		pattern:         pattern,
		matchedDirs:     make(map[string]bool),
		patternSegments: strings.Split(pattern, string(os.PathSeparator)),
	}
}

// ShouldInclude returns true if the file is within a directory matching the pattern
func (m *PatternMatcher) ShouldInclude(path string, info os.FileInfo) bool {
	// For directories, check if they match the pattern and cache the result
	if info.IsDir() {
		matched, err := m.dirMatchesPattern(path)
		if err == nil && matched {
			m.matchedDirs[path] = true
		}
		return false // Don't include the directory itself, only files within
	}

	// For files, check if any parent directory is in the matched set
	dir := filepath.Dir(path)
	for {
		if m.matchedDirs[dir] {
			return true
		}

		// Also check if this directory matches the pattern (in case we haven't seen it yet)
		if matched, err := m.dirMatchesPattern(dir); err == nil && matched {
			m.matchedDirs[dir] = true
			return true
		}

		parent := filepath.Dir(dir)
		if parent == dir || parent == "." {
			break
		}
		dir = parent
	}

	return false
}

// dirMatchesPattern checks if a directory path matches the glob pattern
func (m *PatternMatcher) dirMatchesPattern(dirPath string) (bool, error) {
	// Get the directory name
	dirName := filepath.Base(dirPath)

	// For simple patterns (no path separators), just match the directory name
	if len(m.patternSegments) == 1 {
		return filepath.Match(m.pattern, dirName)
	}

	// For complex patterns, we need to match the full path segments
	pathSegments := strings.Split(dirPath, string(os.PathSeparator))

	// Try to match the pattern segments against the path segments
	if len(pathSegments) < len(m.patternSegments) {
		return false, nil
	}

	// Check each pattern segment against the corresponding path segment
	for i := 0; i < len(m.patternSegments); i++ {
		// Start from the end of both slices
		patternIdx := len(m.patternSegments) - 1 - i
		pathIdx := len(pathSegments) - 1 - i

		matched, err := filepath.Match(m.patternSegments[patternIdx], pathSegments[pathIdx])
		if err != nil {
			return false, err
		}
		if !matched {
			return false, nil
		}
	}

	return true, nil
}

// CompositeMatcher combines multiple matchers with OR logic
type CompositeMatcher struct {
	matchers []Matcher
}

// NewCompositeMatcher creates a matcher that combines multiple matchers
func NewCompositeMatcher(matchers []Matcher) *CompositeMatcher {
	return &CompositeMatcher{matchers: matchers}
}

// ShouldInclude returns true if ANY of the matchers match the file
func (m *CompositeMatcher) ShouldInclude(path string, info os.FileInfo) bool {
	for _, matcher := range m.matchers {
		if matcher.ShouldInclude(path, info) {
			return true
		}
	}
	return false
}