/*
©AngelaMos | 2026
finding.go

Core types for security findings produced by all analyzers

Finding is the central data type flowing through the entire pipeline.
Severity is an ordered enum (Info through Critical) with color
support for terminal output. Collection provides filtering and
aggregation over a slice of findings and is the return type of
every Analyze() call.

Key exports:
  Finding - single security issue with rule ID, severity, target, and
location
  Collection - slice of findings with BySeverity, AtOrAbove,
CountBySeverity
  Severity - ordered enum Info < Low < Medium < High < Critical
  Target, Location, CISControl - embedded context types

Connects to:
  config.go - severity parsing and filter logic
  rules/*.go - severity constants for capability/path classification
  analyzer/*.go - findings created and returned as Collection
  report/*.go - findings consumed by all four reporters
  benchmark/controls.go - CISControl linked to findings via WithCISControl
*/

package finding

import (
	"crypto/sha256"
	"encoding/hex"
	"fmt"
	"strings"
	"time"
)

const (
	containerIDShortLength = 12
	imageIDShortLength     = 12
)

type Severity int

const (
	SeverityInfo Severity = iota
	SeverityLow
	SeverityMedium
	SeverityHigh
	SeverityCritical
)

var severityToString = map[Severity]string{
	SeverityInfo:     "INFO",
	SeverityLow:      "LOW",
	SeverityMedium:   "MEDIUM",
	SeverityHigh:     "HIGH",
	SeverityCritical: "CRITICAL",
}

var stringToSeverity = func() map[string]Severity {
	m := make(map[string]Severity, len(severityToString))
	for sev, str := range severityToString {
		m[str] = sev
	}
	return m
}()

var severityColors = map[Severity]string{
	SeverityInfo:     "\033[36m",
	SeverityLow:      "\033[34m",
	SeverityMedium:   "\033[33m",
	SeverityHigh:     "\033[31m",
	SeverityCritical: "\033[35m",
}

func (s Severity) String() string {
	if str, ok := severityToString[s]; ok {
		return str
	}
	return "UNKNOWN"
}

func (s Severity) Color() string {
	if color, ok := severityColors[s]; ok {
		return color
	}
	return "\033[0m"
}

func ParseSeverity(s string) (Severity, bool) {
	sev, ok := stringToSeverity[strings.ToUpper(strings.TrimSpace(s))]
	return sev, ok
}

type TargetType string

const (
	TargetContainer  TargetType = "container"
	TargetImage      TargetType = "image"
	TargetDockerfile TargetType = "dockerfile"
	TargetCompose    TargetType = "compose"
	TargetDaemon     TargetType = "daemon"
)

type Target struct {
	Type TargetType
	Name string
	ID   string
}

func (t Target) String() string {
	if t.ID != "" && len(t.ID) >= containerIDShortLength {
		return fmt.Sprintf(
			"%s:%s (%s)",
			t.Type,
			t.Name,
			t.ID[:containerIDShortLength],
		)
	}
	if t.ID != "" {
		return fmt.Sprintf("%s:%s (%s)", t.Type, t.Name, t.ID)
	}
	return fmt.Sprintf("%s:%s", t.Type, t.Name)
}

type Location struct {
	Path   string
	Line   int
	Column int
}

func (l Location) String() string {
	if l.Line > 0 {
		return fmt.Sprintf("%s:%d", l.Path, l.Line)
	}
	return l.Path
}

type CISControl struct {
	ID          string
	Section     string
	Title       string
	Description string
	Scored      bool
	Level       int
}

func (c CISControl) String() string {
	return fmt.Sprintf("CIS %s", c.ID)
}

type Finding struct {
	ID          string
	RuleID      string
	Title       string
	Description string
	Severity    Severity
	Category    string
	Target      Target
	Location    *Location
	Remediation string
	References  []string
	CISControl  *CISControl
	Timestamp   time.Time
}

func New(
	ruleID string,
	title string,
	severity Severity,
	target Target,
) *Finding {
	f := &Finding{
		RuleID:    ruleID,
		Title:     title,
		Severity:  severity,
		Target:    target,
		Timestamp: time.Now(),
	}
	f.ID = f.generateID()
	return f
}

func (f *Finding) generateID() string {
	data := fmt.Sprintf(
		"%s|%s|%s|%s",
		f.RuleID,
		f.Target.Type,
		f.Target.Name,
		f.Target.ID,
	)
	if f.Location != nil {
		data += fmt.Sprintf("|%s:%d", f.Location.Path, f.Location.Line)
	}
	hash := sha256.Sum256([]byte(data))
	return hex.EncodeToString(hash[:8])
}

func (f *Finding) WithDescription(desc string) *Finding {
	f.Description = desc
	return f
}

func (f *Finding) WithCategory(cat string) *Finding {
	f.Category = cat
	return f
}

func (f *Finding) WithLocation(loc *Location) *Finding {
	f.Location = loc
	f.ID = f.generateID()
	return f
}

func (f *Finding) WithRemediation(rem string) *Finding {
	f.Remediation = rem
	return f
}

func (f *Finding) WithReferences(refs ...string) *Finding {
	f.References = refs
	return f
}

func (f *Finding) WithCISControl(control *CISControl) *Finding {
	f.CISControl = control
	return f
}

// Collection is a slice of findings with filtering and aggregation methods
type Collection []*Finding

func (c Collection) BySeverity(sev Severity) Collection {
	result := make(Collection, 0, len(c))
	for _, f := range c {
		if f.Severity == sev {
			result = append(result, f)
		}
	}
	return result
}

func (c Collection) AtOrAbove(sev Severity) Collection {
	result := make(Collection, 0, len(c))
	for _, f := range c {
		if f.Severity >= sev {
			result = append(result, f)
		}
	}
	return result
}

func (c Collection) ByCategory(cat string) Collection {
	result := make(Collection, 0, len(c))
	for _, f := range c {
		if f.Category == cat {
			result = append(result, f)
		}
	}
	return result
}

func (c Collection) ByTargetType(tt TargetType) Collection {
	result := make(Collection, 0, len(c))
	for _, f := range c {
		if f.Target.Type == tt {
			result = append(result, f)
		}
	}
	return result
}

func (c Collection) CountBySeverity() map[Severity]int {
	counts := make(map[Severity]int, len(severityToString))
	for _, f := range c {
		counts[f.Severity]++
	}
	return counts
}

func (c Collection) HasSeverityAtOrAbove(sev Severity) bool {
	for _, f := range c {
		if f.Severity >= sev {
			return true
		}
	}
	return false
}

func (c Collection) Total() int {
	return len(c)
}