package recipe

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

	"gmgauthier.com/grokkit/internal/grok"
)

type Runner struct {
	Recipe *Recipe
	Client *grok.Client
	Model  string
}

func NewRunner(r *Recipe, client *grok.Client, model string) *Runner {
	return &Runner{Recipe: r, Client: client, Model: model}
}

func (r *Runner) Run() error {
	fmt.Printf("🍳 Starting recipe: %s v%s\n\n", r.Recipe.Name, r.Recipe.Version)

	var previousResults []string

	for _, step := range r.Recipe.Steps {
		fmt.Printf("Step %d/%d: %s\n", step.Number, len(r.Recipe.Steps), step.Title)

		titleLower := strings.ToLower(step.Title)

		// Only two special cases the CLI ever needs to handle
		switch {
		case strings.Contains(titleLower, "discover") || strings.Contains(titleLower, "find"):
			files := r.discoverFiles()
			result := strings.Join(files, "\n")
			previousResults = append(previousResults, "Discovered files:\n"+result)
			fmt.Println(result)

		case strings.Contains(titleLower, "apply") || strings.Contains(titleLower, "patch"):
			r.handleApplyStep(previousResults)
			continue

		default:
			// Everything else = pure LLM (works for any language)
			prompt := fmt.Sprintf(`Recipe Overview:
%s

Previous step results (for context):
%s

=== CURRENT STEP ===
Objective: %s
Instructions: %s
Expected output format: %s

Execute this step now. Respond ONLY with the expected output format — no explanations, no extra text.`,
				r.Recipe.Overview,
				strings.Join(previousResults, "\n\n---\n\n"),
				step.Objective,
				step.Instructions,
				step.Expected)

			messages := []map[string]string{
				{"role": "system", "content": "You are Grok, built by xAI. Precise expert programmer and refactoring assistant."},
				{"role": "user", "content": prompt},
			}

			response := r.Client.Stream(messages, r.Model)
			fmt.Println()

			previousResults = append(previousResults, fmt.Sprintf("Step %d result:\n%s", step.Number, response))
		}
	}

	fmt.Println("\n✅ Recipe complete.")
	return nil
}

// discoverFiles does a real filesystem scan — generic enough for any Go project
func (r *Runner) discoverFiles() []string {
	var files []string
	root := "internal" // matches the recipe default; we can make it parametric later

	_ = filepath.WalkDir(root, func(path string, d os.DirEntry, err error) error {
		if err != nil || d.IsDir() || !strings.HasSuffix(path, ".go") {
			return nil
		}
		b, _ := os.ReadFile(path)
		if strings.Contains(string(b), "if err != nil") {
			files = append(files, path)
		}
		return nil
	})

	if len(files) == 0 {
		files = append(files, "No files found matching the criteria.")
	}
	return files
}

// handleApplyStep stays exactly as you had it (dry-run patch + confirmation)
func (r *Runner) handleApplyStep(previousResults []string) {
	if len(previousResults) == 0 {
		fmt.Println("   ⚠️  No previous results to apply — skipping.")
		return
	}

	lastResult := previousResults[len(previousResults)-1]
	blocks := extractCodeBlocks(lastResult)

	if len(blocks) == 0 {
		fmt.Println("   ⚠️  No code blocks found to apply — skipping.")
		return
	}

	fmt.Println("   📄 Dry-run mode: creating patch file...")
	patchPath := filepath.Join(".", "recipe-refactor.patch")
	if err := createUnifiedPatch(blocks, patchPath); err != nil {
		fmt.Printf("   ❌ Failed to create patch: %v\n", err)
		return
	}
	fmt.Printf("   ✅ Patch created: %s\n", patchPath)
	fmt.Println("   Review it, then run with dry_run=false to apply.")
}

var blockRe = regexp.MustCompile(`(?s)^//\s*(.+?\.go)\n```go\n(.*?)\n````)

func extractCodeBlocks(text string) map[string]string {
	blocks := make(map[string]string)
	matches := blockRe.FindAllStringSubmatch(text, -1)
	for _, m := range matches {
		if len(m) == 3 {
			blocks[m[1]] = m[2]
		}
	}
	return blocks
}

func createUnifiedPatch(blocks map[string]string, patchPath string) error {
	f, err := os.Create(patchPath)
	if err != nil {
		return err
	}
	defer f.Close()

	for path, content := range blocks {
		fmt.Fprintf(f, "--- %s\n+++ %s\n@@ -0,0 +1,%d @@\n", path, path, strings.Count(content, "\n")+1)
		for _, line := range strings.Split(content, "\n") {
			fmt.Fprintf(f, "+%s\n", line)
		}
	}
	return nil
}