package main

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

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

type comingSoonViolation struct {
	file    string
	line    int
	snippet string
}

var comingSoonAllowedFiles = map[string]bool{
	"components/pages/system-pages-list.tsx":      true, // Real system page type
	"components/settings/ai-action-matrix.tsx":    true, // AI task for site status copy
	"components/settings/site-settings-form.tsx":  true, // Settings navigation text
	"components/settings/site-status-section.tsx": true, // Legitimate Site Status feature UI
	"lib/nav-items.ts":                            true, // Admin navigation metadata
	"routes/admin/pages.tsx":                      true, // System page type enum wiring
	"lib/api/gen/blockninja/v1/pages_pb.d.ts":     true, // Generated proto enum SYSTEM_PAGE_TYPE_COMING_SOON
	"lib/api/gen/blockninja/v1/settings_pb.d.ts":  true, // Generated proto enum SITE_MODE_COMING_SOON
}

var placeholderCopyPatterns = []*regexp.Regexp{
	regexp.MustCompile(`(?i)\bcoming[\s_-]+soon\b`),
	regexp.MustCompile(`(?i)\bunder[\s_-]+construction\b`),
	regexp.MustCompile(`(?i)\bwork[\s_-]+in[\s_-]+progress\b`),
	regexp.MustCompile(`(?i)\bnot[\s_-]+yet[\s_-]+available\b`),
	regexp.MustCompile(`(?i)\bavailable[\s_-]+soon\b`),
	regexp.MustCompile(`(?i)\bcoming[\s_-]+later\b`),
}

var rePlaceholderComment = regexp.MustCompile(`(?i)\bplaceholder\b`)
var rePlaceholderStringLiteral = regexp.MustCompile("`[^`]*\\bplaceholder\\b[^`]*`|\"[^\"]*\\bplaceholder\\b[^\"]*\"|'[^']*\\bplaceholder\\b[^']*'")

// isGeneratedProtoOutput reports whether path lives under a `gen/` directory
// segment — the buf codegen output tree (e.g. `.../lib/api/gen/blockninja/v1/`).
// Scoped to the placeholder/"ship the feature now" check only: generated proto
// code is never hand-authored, so its symbols (COMING_SOON enum values, etc.)
// must not be flagged as placeholder debt.
func isGeneratedProtoOutput(path string) bool {
	return strings.Contains(filepath.ToSlash(path), "/gen/")
}

func checkComingSoon(webSrcDir string) []comingSoonViolation {
	var violations []comingSoonViolation

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

		ext := filepath.Ext(path)
		if !todoFileExts[ext] {
			return nil
		}
		if strings.HasSuffix(path, ".test.ts") || strings.HasSuffix(path, ".test.tsx") {
			return nil
		}
		// Skip buf codegen output (any `gen/` directory segment, e.g.
		// lib/api/gen/blockninja/v1/*_pb.d.ts). These files are regenerated by
		// buf and must never be hand-edited; their enum values like
		// SYSTEM_PAGE_TYPE_COMING_SOON / SITE_MODE_COMING_SOON are real proto
		// symbols, not authored placeholder debt.
		if isGeneratedProtoOutput(path) {
			return nil
		}

		relPath, _ := filepath.Rel(webSrcDir, path)
		if relPath == "" {
			relPath = path
		}
		relPath = filepath.ToSlash(relPath)
		if comingSoonAllowedFiles[relPath] {
			return nil
		}

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

		scanner := bufio.NewScanner(f)
		lineNum := 0
		for scanner.Scan() {
			lineNum++
			line := scanner.Text()
			trimmed := strings.TrimSpace(line)
			if isCommentLine(trimmed) || !containsPlaceholderCopy(line) {
				continue
			}

			violations = append(violations, comingSoonViolation{
				file:    relPath,
				line:    lineNum,
				snippet: strings.TrimSpace(line),
			})
		}

		return nil
	}); err != nil {
		violations = append(violations, comingSoonViolation{
			file:    filepath.ToSlash(webSrcDir),
			snippet: err.Error(),
		})
	}

	sort.Slice(violations, func(i, j int) bool {
		if violations[i].file == violations[j].file {
			return violations[i].line < violations[j].line
		}
		return violations[i].file < violations[j].file
	})

	return violations
}

func checkPlaceholderLanguage(roots []todoScanRoot) []comingSoonViolation {
	var violations []comingSoonViolation

	for _, scanRoot := range roots {
		if scanRoot.root == "" {
			continue
		}

		if err := filepath.Walk(scanRoot.root, func(path string, info os.FileInfo, err error) error {
			if err != nil {
				return nil
			}
			if info.IsDir() {
				if todoDirSkips[info.Name()] {
					return filepath.SkipDir
				}
				return nil
			}

			ext := filepath.Ext(path)
			if ext != ".go" && ext != ".tsx" {
				return nil
			}
			if strings.HasSuffix(path, "_test.go") || strings.HasSuffix(path, ".test.tsx") {
				return nil
			}
			slashPath := filepath.ToSlash(path)
			if strings.Contains(slashPath, "/generated/") ||
				strings.HasSuffix(slashPath, ".pb.go") ||
				strings.HasSuffix(slashPath, ".connect.go") ||
				isGeneratedProtoOutput(path) {
				return nil
			}
			if strings.Contains(filepath.ToSlash(path), "cmd/check-safety/") {
				return nil
			}

			relPath, _ := filepath.Rel(scanRoot.root, path)
			if relPath == "" {
				relPath = path
			}
			relPath = filepath.ToSlash(relPath)
			if isAllowedPlaceholderFile(relPath) {
				return nil
			}
			if scanRoot.displayPrefix != "" {
				relPath = scanRoot.displayPrefix + "/" + relPath
			}
			if isAllowedPlaceholderFile(relPath) {
				return nil
			}
			f, openErr := os.Open(path)
			if openErr != nil {
				return nil
			}
			defer helpers.LogDeferredError(nil, "close placeholder scan file", f.Close, "path", path)

			scanner := bufio.NewScanner(f)
			lineNum := 0
			for scanner.Scan() {
				lineNum++
				line := scanner.Text()
				trimmed := strings.TrimSpace(line)
				if !containsPlaceholderLanguage(line, trimmed) {
					continue
				}

				violations = append(violations, comingSoonViolation{
					file:    relPath,
					line:    lineNum,
					snippet: trimmed,
				})
			}

			return nil
		}); err != nil {
			violations = append(violations, comingSoonViolation{
				file:    filepath.ToSlash(scanRoot.root),
				snippet: err.Error(),
			})
		}
	}

	sort.Slice(violations, func(i, j int) bool {
		if violations[i].file == violations[j].file {
			return violations[i].line < violations[j].line
		}
		return violations[i].file < violations[j].file
	})

	return violations
}

func containsPlaceholderLanguage(line string, trimmed string) bool {
	lowerLine := strings.ToLower(line)
	if strings.Contains(lowerLine, "placeholder=") || strings.Contains(lowerLine, "placeholder:") || strings.Contains(lowerLine, "=placeholder") {
		return false
	}
	if strings.Contains(lowerLine, `.placeholder`) ||
		strings.Contains(lowerLine, `["placeholder"]`) ||
		strings.Contains(lowerLine, `['placeholder']`) ||
		strings.Contains(lowerLine, `json:"placeholder`) ||
		strings.Contains(lowerLine, `data-[placeholder]`) {
		return false
	}

	if isPlaceholderCommentLine(trimmed) && rePlaceholderComment.MatchString(line) {
		lower := strings.ToLower(trimmed)
		if strings.Contains(lower, "render a placeholder") ||
			strings.Contains(lower, "renders a placeholder") ||
			strings.Contains(lower, "show placeholder") ||
			strings.Contains(lower, "show empty placeholder") ||
			strings.Contains(lower, "slug placeholder") ||
			strings.Contains(lower, "variable placeholder") ||
			strings.Contains(lower, "placeholder patterns") ||
			strings.Contains(lower, `"placeholder"`) ||
			strings.Contains(lower, "`placeholder`") ||
			strings.Contains(lower, "placeholder with edit button") ||
			strings.Contains(lower, "streaming placeholder") ||
			strings.Contains(lower, "message placeholder") ||
			strings.Contains(lower, "placeholder on error") ||
			strings.Contains(lower, "empty placeholder") ||
			strings.Contains(lower, "placeholder color") ||
			strings.Contains(lower, "placeholder option") {
			return false
		}
		return true
	}

	for _, match := range rePlaceholderStringLiteral.FindAllString(line, -1) {
		literal := strings.TrimSpace(strings.Trim(match, "\"'`"))
		if literal == "" {
			continue
		}
		if strings.EqualFold(literal, "placeholder") {
			continue
		}
		if strings.HasPrefix(strings.ToLower(literal), "placeholder-") {
			continue
		}
		if strings.Contains(strings.ToLower(literal), "slot-placeholder") {
			continue
		}
		switch strings.ToLower(literal) {
		case "placeholder color", "placeholder text color":
			continue
		}
		switch strings.ToLower(literal) {
		case "placeholder content":
			continue
		}
		return true
	}

	return false
}

func containsPlaceholderCopy(line string) bool {
	for _, pattern := range placeholderCopyPatterns {
		if pattern.MatchString(line) {
			return true
		}
	}

	return false
}

func isPlaceholderCommentLine(trimmed string) bool {
	return strings.HasPrefix(trimmed, "//") ||
		strings.HasPrefix(trimmed, "/*") ||
		strings.HasPrefix(trimmed, "*") ||
		strings.HasPrefix(trimmed, "{/*")
}

func isAllowedPlaceholderFile(relPath string) bool {
	normalized := strings.TrimPrefix(filepath.ToSlash(relPath), "web/src/")
	return comingSoonAllowedFiles[normalized]
}