package main

import (
	"bufio"
	"os"
	"path/filepath"
	"regexp"
	"strings"

	"git.dev.alexdunmow.com/block/check-safety/internal/helpers"
)

type colorViolation struct {
	file    string
	line    int
	rule    string
	snippet string
}

// reHexInTemplClass checks for hex colors in HTML class= attributes (templ syntax uses class=, not className=)
var reHexInTemplClass = regexp.MustCompile(`class=["'][^"']*#[0-9a-fA-F]{3,8}`)

// reInlineHexTemplStyle matches raw hex colors in templ style= string literals.
var reInlineHexTemplStyle = regexp.MustCompile(`style=(?:\{\s*)?["'][^"']*(?:color|background(?:-color)?)\s*:\s*#[0-9a-fA-F]{3,8}`)

// reInlineRGBTemplStyle matches literal rgb()/hsl() colors in templ style= string literals.
var reInlineRGBTemplStyle = regexp.MustCompile(`style=(?:\{\s*)?["'][^"']*(?:color|background(?:-color)?)\s*:\s*(?:rgb|hsl)a?\([^"']*\)`)

// checkTemplColors scans .templ files under root for hardcoded color violations.
// Templ files use HTML class= (not React className=), so they need separate handling.
func checkTemplColors(root string) []colorViolation {
	var violations []colorViolation

	if err := filepath.Walk(root, func(path string, info os.FileInfo, err error) error {
		if err != nil || info.IsDir() {
			return nil
		}
		if filepath.Ext(path) != ".templ" {
			return nil
		}
		if strings.Contains(path, "/vendor/") || strings.Contains(path, "/.git/") {
			return nil
		}

		relPath, _ := filepath.Rel(root, path)
		if relPath == "" {
			relPath = path
		}

		if isColorAllowed(relPath) {
			return nil
		}

		f, err := os.Open(path)
		if err != nil {
			return nil
		}
		defer helpers.LogDeferredError(nil, "close templ color scan file", f.Close, "path", path)

		scanner := bufio.NewScanner(f)
		lineNum := 0
		for scanner.Scan() {
			lineNum++
			line := scanner.Text()
			trimmed := strings.TrimSpace(line)

			if strings.HasPrefix(trimmed, "//") || strings.HasPrefix(trimmed, "*") || strings.HasPrefix(trimmed, "/*") {
				continue
			}
			if reColorDataKey.MatchString(trimmed) &&
				!strings.Contains(trimmed, "class=") &&
				!strings.Contains(trimmed, "className=") &&
				!strings.Contains(trimmed, "style=") {
				continue
			}

			if reTwHardcodedColor.MatchString(line) {
				match := reTwHardcodedColor.FindString(line)
				violations = append(violations, colorViolation{
					file: relPath, line: lineNum, rule: "no-hardcoded-tw-color",
					snippet: match,
				})
			}

			if reHexInTemplClass.MatchString(line) {
				violations = append(violations, colorViolation{
					file: relPath, line: lineNum, rule: "no-hex-in-class",
					snippet: strings.TrimSpace(reHexInTemplClass.FindString(line)),
				})
			}

			if reTwArbitraryHex.MatchString(line) {
				violations = append(violations, colorViolation{
					file: relPath, line: lineNum, rule: "no-tw-arbitrary-hex",
					snippet: reTwArbitraryHex.FindString(line),
				})
			}

			if reTwArbitraryRGB.MatchString(line) {
				violations = append(violations, colorViolation{
					file: relPath, line: lineNum, rule: "no-tw-arbitrary-rgb",
					snippet: reTwArbitraryRGB.FindString(line),
				})
			}

			if reInlineHexTemplStyle.MatchString(line) {
				violations = append(violations, colorViolation{
					file: relPath, line: lineNum, rule: "no-inline-hex-style",
					snippet: strings.TrimSpace(reInlineHexTemplStyle.FindString(line)),
				})
			}

			if reInlineRGBTemplStyle.MatchString(line) && !strings.Contains(line, "var(--") {
				violations = append(violations, colorViolation{
					file: relPath, line: lineNum, rule: "no-inline-rgb-style",
					snippet: strings.TrimSpace(reInlineRGBTemplStyle.FindString(line)),
				})
			}
		}

		return nil
	}); err != nil {
		violations = append(violations, colorViolation{
			file:    filepath.ToSlash(root),
			line:    0,
			rule:    "walk-error",
			snippet: err.Error(),
		})
	}

	return violations
}

// Only files that ARE theme definitions may have raw color values.
var colorAllowedDirs []string
var colorAllowedFiles = map[string]bool{
	"routes/admin/system.tsx":                    true, // Theme preset picker — displays theme color swatches using actual HSL values
	"components/settings/theme-card.tsx":         true, // Orchestrator theme gallery — preview swatches need real HSL ramps
	"routes/dashboard/sites/new/step-design.tsx": true, // Template chooser artwork uses explicit preview ramps
}

// Tailwind color names that should use semantic tokens instead
var twColorNames = []string{
	"gray", "slate", "zinc", "neutral", "stone",
	"red", "orange", "amber", "yellow", "lime",
	"green", "emerald", "teal", "cyan", "sky",
	"blue", "indigo", "violet", "purple", "fuchsia",
	"pink", "rose",
}

var (
	// Matches: text-blue-500, bg-red-100, border-green-700, ring-amber-300, etc.
	// Also matches hover:, focus:, dark: variants
	reTwHardcodedColor *regexp.Regexp

	// Matches: #fff, #000000, #3b82f6, etc. in className or JSX strings
	reHexInClass = regexp.MustCompile(`className=["'\x60][^"'\x60]*#[0-9a-fA-F]{3,8}`)

	// Matches: style={{ color: '#...', backgroundColor: '#...' }} with string literals
	reInlineHexStyle = regexp.MustCompile(`style=\{?\{[^}]*(?:color|backgroundColor|background)\s*:\s*['"]#[0-9a-fA-F]{3,8}['"]`)

	// Matches: style={{ color: 'rgb(...)', backgroundColor: 'hsl(...)' }} with string literals (not var(--)
	reInlineRGBStyle = regexp.MustCompile(`style=\{?\{[^}]*(?:color|backgroundColor|background)\s*:\s*['"](?:rgb|hsl)a?\([^)]*\)['"]`)

	// Matches Tailwind arbitrary hex values: bg-[#ff0000], text-[#333], border-[#abc123]
	reTwArbitraryHex = regexp.MustCompile(`(?:bg|text|border|ring|fill|stroke)-\[#[0-9a-fA-F]{3,8}\]`)

	// Matches Tailwind arbitrary rgb/hsl values: bg-[rgb(255,0,0)], text-[hsl(0,100%,50%)]
	reTwArbitraryRGB = regexp.MustCompile(`(?:bg|text|border)-\[(?:rgb|hsl)a?\([^)]+\)\]`)

	// Heuristic: skip lines that are defining data/constants (color maps, arrays)
	reColorDataKey = regexp.MustCompile(`(?:hex|value|color)\s*[:=]`)
)

func init() {
	// Build regex for tailwind hardcoded colors: (dark:|hover:|focus:)?(bg|text|border|ring|shadow|outline|decoration|divide|from|to|via)-(color)-(shade)
	var colorAlts []string
	colorAlts = append(colorAlts, twColorNames...)
	colorGroup := strings.Join(colorAlts, "|")
	// Match in className strings — look for the Tailwind class pattern
	reTwHardcodedColor = regexp.MustCompile(
		`(?:(?:dark|hover|focus|active|group-hover|peer-hover|disabled):)*` +
			`(?:bg|text|border|ring|shadow|outline|decoration|divide|from|to|via|fill|stroke|accent|caret|placeholder)-` +
			`(?:` + colorGroup + `)-` +
			`\d{2,3}`,
	)
}

func isColorAllowed(relPath string) bool {
	// The color allowlist keys are source-relative (e.g.
	// "components/settings/theme-card.tsx"), but relPath is computed relative to
	// whatever scan root the caller used. That root varies by repo: the CMS
	// frontend scan root is "web/src" (relPath = "components/..."), while the
	// orchestrator's is "frontend" (relPath = "src/components/..."). Trim any of
	// these leading source prefixes so one allowlist entry matches regardless of
	// which repo is the primary scan target. Mirrors isAllowedPlaceholderFile's
	// web/src trimming.
	normalized := filepath.ToSlash(relPath)
	normalized = strings.TrimPrefix(normalized, "web/src/")
	normalized = strings.TrimPrefix(normalized, "frontend/src/")
	normalized = strings.TrimPrefix(normalized, "src/")
	if colorAllowedFiles[normalized] {
		return true
	}
	if colorAllowedFiles[relPath] {
		return true
	}
	for _, dir := range colorAllowedDirs {
		if strings.HasPrefix(relPath, dir) {
			return true
		}
	}
	// Files with "color" in the name are likely color utilities
	base := filepath.Base(relPath)
	return strings.Contains(strings.ToLower(base), "color")
}

// reNinjaTplHardcodedHSL matches hsl() with literal numeric hue values — not CSS variable references.
// Flags: hsl(168, 82%, 46%), hsl(150 27% 33%)
// Allows: hsl(var(--primary)), hsl(var(--background))
var reNinjaTplHardcodedHSL = regexp.MustCompile(`\bhsl\(\s*\d`)

// reNinjaTplHardcodedRGB matches rgb()/rgba() with literal numeric values.
var reNinjaTplHardcodedRGB = regexp.MustCompile(`\brgba?\(\s*(\d+)\s*,\s*(\d+)\s*,\s*(\d+)`)

// reNinjaTplArbitraryColor matches Tailwind arbitrary HSL/RGB/RGBA values in class= attributes.
// Flags: text-[hsl(168,82%,46%)], bg-[rgba(130,70,220,0.1)], border-[rgb(0,205,155)]
var reNinjaTplArbitraryColor = regexp.MustCompile(
	`(?:bg|text|border|ring|fill|stroke|from|to|via)-\[(?:hsl|rgb|rgba)\([^)]+\)\]`,
)

// reNinjaTplArbitraryHex matches Tailwind arbitrary hex values: bg-[#ff0000], text-[#333]
var reNinjaTplArbitraryHex = regexp.MustCompile(`(?:bg|text|border|ring|fill|stroke)-\[#[0-9a-fA-F]{3,8}\]`)

// reNinjaTplInlineHex matches hex colors inside style= attributes.
var reNinjaTplInlineHex = regexp.MustCompile(`style=[^>]*#[0-9a-fA-F]{3,8}`)

// reNinjaTplExtractRGB extracts the first three RGB components from an rgb/rgba call.
var reNinjaTplExtractRGB = regexp.MustCompile(`\brgba?\(\s*(\d+)\s*,\s*(\d+)\s*,\s*(\d+)`)

// isNeutralRGB reports whether an rgb/rgba match uses only 0 or 255 for all three channels
// (pure black, pure white, or transparent). These are structural overlays, not brand colors.
func isNeutralRGB(match string) bool {
	m := reNinjaTplExtractRGB.FindStringSubmatch(match)
	if m == nil {
		return false
	}
	for _, v := range m[1:4] {
		if v != "0" && v != "255" {
			return false
		}
	}
	return true
}

// checkNinjaTplColors scans .ninjatpl block templates under root for hardcoded color violations.
// All colors in .ninjatpl files must use CSS custom properties (hsl(var(--token))) rather than
// literal HSL, RGB, RGBA, or hex values.
func checkNinjaTplColors(root string) []colorViolation {
	var violations []colorViolation

	if err := filepath.Walk(root, func(path string, info os.FileInfo, err error) error {
		if err != nil || info.IsDir() {
			return nil
		}
		if filepath.Ext(path) != ".ninjatpl" {
			return nil
		}
		if strings.Contains(path, "/vendor/") || strings.Contains(path, "/.git/") {
			return nil
		}
		// Email wrapper templates (templates/email/*.ninjatpl) legitimately
		// require literal hex: mail clients don't support CSS custom
		// properties, so themed emails inline resolved theme colors
		// ({{ colors.* }}) with hex fallbacks (WO-WZ-021).
		if strings.Contains(filepath.ToSlash(path), "/templates/email/") {
			return nil
		}

		relPath, _ := filepath.Rel(root, path)
		if relPath == "" {
			relPath = path
		}

		f, err := os.Open(path)
		if err != nil {
			return nil
		}
		defer helpers.LogDeferredError(nil, "close ninjatpl color scan file", f.Close, "path", path)

		scanner := bufio.NewScanner(f)
		lineNum := 0
		for scanner.Scan() {
			lineNum++
			line := scanner.Text()
			trimmed := strings.TrimSpace(line)

			// Skip HTML comments
			if strings.HasPrefix(trimmed, "<!--") {
				continue
			}

			// 1. Hardcoded hsl() with literal values (not var(--)
			if reNinjaTplHardcodedHSL.MatchString(line) {
				for _, m := range reNinjaTplHardcodedHSL.FindAllStringIndex(line, -1) {
					ctx := line[m[0]:]
					if !strings.HasPrefix(ctx, "hsl(var(") {
						violations = append(violations, colorViolation{
							file: relPath, line: lineNum, rule: "no-hardcoded-hsl",
							snippet: line[m[0]:min(m[0]+30, len(line))],
						})
					}
				}
			}

			// 2. Hardcoded rgb()/rgba() with non-neutral values
			if reNinjaTplHardcodedRGB.MatchString(line) {
				for _, m := range reNinjaTplHardcodedRGB.FindAllString(line, -1) {
					if !isNeutralRGB(m) {
						violations = append(violations, colorViolation{
							file: relPath, line: lineNum, rule: "no-hardcoded-rgb",
							snippet: m,
						})
					}
				}
			}

			// 3. Hex colors in style= attributes
			if reNinjaTplInlineHex.MatchString(line) {
				violations = append(violations, colorViolation{
					file: relPath, line: lineNum, rule: "no-inline-hex",
					snippet: strings.TrimSpace(reNinjaTplInlineHex.FindString(line)),
				})
			}

			// 4. Tailwind arbitrary hsl/rgb/rgba values: text-[hsl(...)], bg-[rgba(...)]
			if reNinjaTplArbitraryColor.MatchString(line) {
				violations = append(violations, colorViolation{
					file: relPath, line: lineNum, rule: "no-tw-arbitrary-color",
					snippet: reNinjaTplArbitraryColor.FindString(line),
				})
			}

			// 5. Tailwind arbitrary hex values: bg-[#333], text-[#ff0000]
			if reNinjaTplArbitraryHex.MatchString(line) {
				violations = append(violations, colorViolation{
					file: relPath, line: lineNum, rule: "no-tw-arbitrary-hex",
					snippet: reNinjaTplArbitraryHex.FindString(line),
				})
			}

			// 6. Tailwind named color classes (e.g. text-blue-500, bg-amber-200)
			if reTwHardcodedColor.MatchString(line) {
				violations = append(violations, colorViolation{
					file: relPath, line: lineNum, rule: "no-hardcoded-tw-color",
					snippet: reTwHardcodedColor.FindString(line),
				})
			}
		}

		return nil
	}); err != nil {
		violations = append(violations, colorViolation{
			file:    filepath.ToSlash(root),
			line:    0,
			rule:    "walk-error",
			snippet: err.Error(),
		})
	}

	return violations
}

func checkColors(webSrcDir string) []colorViolation {
	var violations []colorViolation

	if err := filepath.Walk(webSrcDir, func(path string, info os.FileInfo, err error) error {
		if err != nil || info.IsDir() {
			return nil
		}

		ext := filepath.Ext(path)
		if ext != ".tsx" && ext != ".ts" && ext != ".jsx" {
			return nil
		}
		if strings.Contains(path, "node_modules") || strings.Contains(path, "/dist/") {
			return nil
		}

		relPath, _ := filepath.Rel(webSrcDir, path)
		if relPath == "" {
			relPath = path
		}

		if isColorAllowed(relPath) {
			return nil
		}

		f, err := os.Open(path)
		if err != nil {
			return nil
		}
		defer helpers.LogDeferredError(nil, "close frontend color scan file", f.Close, "path", path)

		scanner := bufio.NewScanner(f)
		lineNum := 0
		for scanner.Scan() {
			lineNum++
			line := scanner.Text()
			trimmed := strings.TrimSpace(line)

			// Skip comments
			if strings.HasPrefix(trimmed, "//") || strings.HasPrefix(trimmed, "*") || strings.HasPrefix(trimmed, "/*") {
				continue
			}

			// Skip SVG fill/stroke attributes (these can't use Tailwind classes)
			if strings.Contains(trimmed, "fill=") || strings.Contains(trimmed, "stroke=") {
				if !strings.Contains(trimmed, "className") {
					continue
				}
			}

			// Skip lines that are just defining data/constants (color maps, arrays)
			// Heuristic: if the line contains hex/value/color as an object key, it's data
			if reColorDataKey.MatchString(trimmed) &&
				!strings.Contains(trimmed, "class=") &&
				!strings.Contains(trimmed, "className=") &&
				!strings.Contains(trimmed, "style=") {
				continue
			}

			// Check for Tailwind hardcoded color classes
			if reTwHardcodedColor.MatchString(line) {
				match := reTwHardcodedColor.FindString(line)
				violations = append(violations, colorViolation{
					file: relPath, line: lineNum, rule: "no-hardcoded-tw-color",
					snippet: match,
				})
			}

			// Check for hex colors in className
			if reHexInClass.MatchString(line) {
				violations = append(violations, colorViolation{
					file: relPath, line: lineNum, rule: "no-hex-in-className",
					snippet: strings.TrimSpace(reHexInClass.FindString(line)),
				})
			}

			// Check for inline style hex colors (skip if value is a variable)
			if reInlineHexStyle.MatchString(line) {
				violations = append(violations, colorViolation{
					file: relPath, line: lineNum, rule: "no-inline-hex-style",
					snippet: strings.TrimSpace(reInlineHexStyle.FindString(line)),
				})
			}

			// Check for inline style rgb/hsl with literal values (not css variables)
			if reInlineRGBStyle.MatchString(line) {
				// Skip if it's using css variables: hsl(var(--...))
				if !strings.Contains(line, "var(--") {
					violations = append(violations, colorViolation{
						file: relPath, line: lineNum, rule: "no-inline-rgb-style",
						snippet: strings.TrimSpace(reInlineRGBStyle.FindString(line)),
					})
				}
			}

			// Check for Tailwind arbitrary hex values: bg-[#ff0000], text-[#333]
			if reTwArbitraryHex.MatchString(line) {
				violations = append(violations, colorViolation{
					file: relPath, line: lineNum, rule: "no-tw-arbitrary-hex",
					snippet: strings.TrimSpace(reTwArbitraryHex.FindString(line)),
				})
			}

			// Check for Tailwind arbitrary rgb/hsl values: bg-[rgb(255,0,0)]
			if reTwArbitraryRGB.MatchString(line) {
				violations = append(violations, colorViolation{
					file: relPath, line: lineNum, rule: "no-tw-arbitrary-rgb",
					snippet: strings.TrimSpace(reTwArbitraryRGB.FindString(line)),
				})
			}
		}

		return nil
	}); err != nil {
		violations = append(violations, colorViolation{
			file:    filepath.ToSlash(webSrcDir),
			line:    0,
			rule:    "walk-error",
			snippet: err.Error(),
		})
	}

	return violations
}