package cmd

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

	"github.com/spf13/cobra"
	"github.com/spf13/viper"

	"gmgauthier.com/grokkit/config"
	"gmgauthier.com/grokkit/internal/git"
	"gmgauthier.com/grokkit/internal/grok"
	"gmgauthier.com/grokkit/internal/linter"
	"gmgauthier.com/grokkit/internal/logger"
	"gmgauthier.com/grokkit/internal/prompts" // new package (see below)
)

var analyzeCmd = &cobra.Command{
	Use:   "analyze [flags]",
	Short: "Deep project analysis → educational Markdown report",
	Long: `Analyzes the repository root and generates a didactic Markdown report.
Uses language-specific prompts discovered in .grokkit/prompts/ or ~/.config/grokkit/prompts/.`,
	Run: func(cmd *cobra.Command, args []string) {
		dir := viper.GetString("dir")
		if dir == "" {
			dir = "."
		}
		output := viper.GetString("output")
		if output == "" {
			output = "analyze.md"
		}
		model := config.GetModel(viper.GetString("model"))
		yes := viper.GetBool("yes")

		log := logger.Get()

		// Safety: note if not in git repo
		if !git.IsRepo(dir) {
			log.Warn("Not inside a git repository. Git metadata in report will be limited.")
		}

		// 1. Discover source files
		files, err := discoverSourceFiles(dir)
		if err != nil {
			log.Error("Failed to discover source files", "dir", dir, "error", err)
			os.Exit(1)
		}
		if len(files) == 0 {
			fmt.Printf("No supported source files found in %s\n", dir)
			os.Exit(1)
		}

		// 2. Detect primary language (extend linter as needed)
		lang := linter.DetectPrimaryLanguage(files)
		if lang == "" {
			lang = "unknown"
		}

		// 3. Load language-specific prompt (project → global)
		promptPath, promptContent, err := prompts.LoadAnalysisPrompt(dir, lang)
		if err != nil {
			fmt.Printf("Error: Could not find analysis prompt for language '%s'.\n\n", lang)
			fmt.Println("Create one of the following files:")
			fmt.Printf("  %s\n", filepath.Join(dir, ".grokkit", "prompts", lang+".md"))
			fmt.Printf("  %s\n", filepath.Join(os.Getenv("HOME"), ".config", "grokkit", "prompts", lang+".md"))
			fmt.Println("\nExample starter content:")
			fmt.Println(`You are an expert ` + lang + ` educator...`)
			os.Exit(1)
		}
		log.Info("Loaded analysis prompt", "language", lang, "path", promptPath)

		// 4. Build rich project context (tree, key files, git info, etc.)
		context := buildProjectContext(dir, files)

		// 5. Call Grok (silent stream for full report)
		messages := []map[string]string{
			{"role": "system", "content": promptContent},
			{"role": "user", "content": "Analyze the following project and generate the full educational Markdown report:\n\n" + context},
		}

		report, err := grok.GetClient().StreamSilent(messages, model)
		if err != nil {
			log.Error("Grok analysis failed", "error", err)
			os.Exit(1)
		}

		// 6. Transactional preview + confirmation
		if !yes {
			fmt.Println("\n=== Proposed Analysis Report Preview (first 60 lines) ===")
			previewLines(report, 60)
			fmt.Printf("\nWrite report to %s? (y/N): ", output)
			var confirm string
			fmt.Scanln(&confirm)
			if !strings.HasPrefix(strings.ToLower(confirm), "y") {
				fmt.Println("Analysis cancelled by user.")
				return
			}
		}

		// 7. Output
		if output == "-" {
			fmt.Println(report)
			return
		}

		if err := os.WriteFile(output, []byte(report), 0644); err != nil {
			log.Error("Failed to write report", "file", output, "error", err)
			os.Exit(1)
		}

		fmt.Printf("✅ Educational analysis report written to %s\n", output)
		fmt.Println("Review it with: less " + output)
	},
}

func init() {
	analyzeCmd.Flags().String("dir", ".", "Repository root to analyze")
	analyzeCmd.Flags().StringP("output", "o", "analyze.md", "Output file (use - for stdout)")
	analyzeCmd.Flags().BoolP("yes", "y", false, "Skip confirmation prompt")
	// model flag is handled globally via config.GetModel

	rootCmd.AddCommand(analyzeCmd)
}

// discoverSourceFiles walks the directory and collects supported source files.
// Extend this if you want deeper recursion or ignore patterns.
func discoverSourceFiles(root string) ([]string, error) {
	var files []string
	err := filepath.Walk(root, func(path string, info os.FileInfo, err error) error {
		if err != nil {
			return err
		}
		if info.IsDir() && (strings.HasPrefix(info.Name(), ".") || info.Name() == "node_modules" || info.Name() == "vendor") {
			return filepath.SkipDir
		}
		if !info.IsDir() {
			if _, err := linter.DetectLanguage(path); err == nil {
				files = append(files, path)
			}
		}
		return nil
	})
	return files, err
}

// previewLines prints the first N lines of the report.
func previewLines(content string, n int) {
	scanner := bufio.NewScanner(strings.NewReader(content))
	for i := 0; i < n && scanner.Scan(); i++ {
		fmt.Println(scanner.Text())
	}
	if scanner.Err() != nil {
		fmt.Println("... (preview truncated)")
	}
}

// buildProjectContext harvests useful context (tree, go.mod, git remote, etc.).
// Expand this as needed for other languages.
func buildProjectContext(dir string, files []string) string {
	var sb strings.Builder
	sb.WriteString("Project Directory: " + dir + "\n\n")

	// Simple tree summary (or call tree/git ls-files if desired)
	sb.WriteString("Source files found: " + fmt.Sprintf("%d\n\n", len(files)))

	// Git info
	if remotes, err := git.Run([]string{"remote", "-v"}); err == nil {
		sb.WriteString("Git Remotes:\n" + remotes + "\n\n")
	}

	// Add more (go.mod, package.json, Cargo.toml, etc.) here for richer context
	return sb.String()
}