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"
)

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 = filepath.Join(".grokkit", "analysis.md")
		}
		model := config.GetModel("analyze", viper.GetString("model"))
		yes := viper.GetBool("yes")

		if !git.IsRepo() {
			logger.Warn("Not inside a git repository. Git metadata in report will be limited.")
		}

		files, err := discoverSourceFiles(dir)
		if err != nil {
			logger.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)
		}

		lang := linter.DetectPrimaryLanguage(files)
		if lang == "" {
			lang = "unknown"
		}

		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)
		}
		logger.Info("Loaded analysis prompt", "language", lang, "path", promptPath)
		projectName := filepath.Base(dir)
		if projectName == "." {
			projectName = "Current Project"
		}
		promptContent = strings.Replace(promptContent, "[Inferred Project Name]", projectName, 1)

		context := buildProjectContext(dir, files)

		messages := []map[string]string{
			{"role": "system", "content": promptContent},
			{"role": "user", "content": fmt.Sprintf("Analyze this %s project and generate the full educational Markdown report now:\n\n%s", lang, context)},
		}

		report := grok.NewClient().StreamSilent(messages, model)

		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
			_, err := fmt.Scanln(&confirm)
			if err != nil {
				return
			}
			if !strings.HasPrefix(strings.ToLower(confirm), "y") {
				fmt.Println("Analysis cancelled by user.")
				return
			}
		}

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

		if err := os.MkdirAll(".grokkit", 0755); err != nil {
			logger.Error("Failed to create .grokkit directory", "error", err)
			os.Exit(1)
		}
		if err := os.WriteFile(output, []byte(report), 0644); err != nil {
			logger.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")
}

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
		}

		name := info.Name()
		if info.IsDir() {
			if strings.HasPrefix(name, ".") && name != "." && name != ".." ||
				name == "node_modules" || name == "vendor" || name == "build" || name == "dist" {
				return filepath.SkipDir
			}
			return nil
		}

		if _, detectErr := linter.DetectLanguage(path); detectErr == nil {
			files = append(files, path)
		}
		return nil
	})
	return files, err
}

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)")
	}
}

func buildProjectContext(dir string, files []string) string {
	var sb strings.Builder
	sb.WriteString("Project Root: " + dir + "\n\n")
	_, err := fmt.Fprintf(&sb, "Total source files discovered: %d\n\n", len(files))
	if err != nil {
		return ""
	}

	sb.WriteString("Key files (top-level view):\n")
	for _, f := range files {
		rel, _ := filepath.Rel(dir, f)
		if strings.Count(rel, string(filepath.Separator)) <= 2 {
			sb.WriteString("  - " + rel + "\n")
		}
		if sb.Len() > 2500 {
			break
		}
	}

	if out, err := git.Run([]string{"remote", "-v"}); err == nil && out != "" {
		sb.WriteString("\nGit Remotes:\n" + out + "\n")
	}

	return sb.String()
}