package recipe

import (
	"encoding/json"
	"fmt"
	"os"
	"os/exec"
	"path/filepath"
	"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)

	// Resolve the final working directory once (package_path + project_name)
	workDir := r.resolveWorkDir()

	var previousResults []string
	var refactorJSONs []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)

		switch {
		case strings.Contains(titleLower, "discover") || strings.Contains(titleLower, "find"):
			files := r.discoverFiles(workDir)
			result := strings.Join(files, "\n")
			previousResults = append(previousResults, "Discovered files:\n"+result)
			fmt.Println(result)

		case strings.Contains(titleLower, "refactor"):
			r.refactorFiles(previousResults, &refactorJSONs)
			continue

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

		case strings.Contains(titleLower, "initialize") || strings.Contains(titleLower, "create") ||
			strings.Contains(titleLower, "run") || strings.Contains(titleLower, "shell") ||
			strings.Contains(titleLower, "poetry") || strings.Contains(titleLower, "git") ||
			strings.Contains(titleLower, "tea"):
			r.executeShellCommands(step, previousResults, workDir)
			continue

		default:
			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
}

// resolveWorkDir returns the absolute path where all shell commands should run
func (r *Runner) resolveWorkDir() string {
	// Start with package_path param or default
	root := "."
	if v, ok := r.Recipe.ResolvedParams["package_path"]; ok {
		if s, ok := v.(string); ok && s != "" {
			root = s
		}
	}

	// Expand ~
	if strings.HasPrefix(root, "~/") {
		home, _ := os.UserHomeDir()
		root = filepath.Join(home, root[2:])
	} else if root == "~" {
		root, _ = os.UserHomeDir()
	}

	// Make absolute
	absRoot, err := filepath.Abs(root)
	if err != nil {
		absRoot = root
	}

	// Append project_name if provided
	if name, ok := r.Recipe.ResolvedParams["project_name"]; ok {
		if s, ok := name.(string); ok && s != "" {
			absRoot = filepath.Join(absRoot, s)
		}
	}

	return absRoot
}

// resolvePackagePath expands ~, ., and makes the path absolute
func (r *Runner) resolvePackagePath() string {
	root := "."
	if v, ok := r.Recipe.ResolvedParams["package_path"]; ok {
		if s, ok := v.(string); ok && s != "" {
			root = s
		}
	}

	// Expand ~
	if strings.HasPrefix(root, "~/") {
		home, _ := os.UserHomeDir()
		root = filepath.Join(home, root[2:])
	} else if root == "~" {
		root, _ = os.UserHomeDir()
	}

	// Make absolute
	abs, err := filepath.Abs(root)
	if err != nil {
		abs = root
	}
	return abs
}

// discoverFiles now takes the resolved absolute path
// discoverFiles now takes the resolved workDir
func (r *Runner) discoverFiles(workDir string) []string {
	var files []string

	allowedExt := make(map[string]bool)
	for _, lang := range r.Recipe.ProjectLanguages {
		if exts, ok := r.Recipe.Extensions[lang]; ok {
			for _, ext := range exts {
				allowedExt[ext] = true
			}
		}
	}

	searchFor := r.Recipe.SearchPattern
	if searchFor == "" {
		searchFor = "if err != nil"
	}

	_ = filepath.WalkDir(workDir, func(path string, d os.DirEntry, err error) error {
		if err != nil || d.IsDir() {
			return nil
		}
		if allowedExt[filepath.Ext(path)] {
			b, _ := os.ReadFile(path)
			if strings.Contains(string(b), searchFor) {
				files = append(files, path)
			}
		}
		return nil
	})

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

// refactorFiles — one file at a time
func (r *Runner) refactorFiles(previousResults []string, refactorJSONs *[]string) {
	discoveredLine := previousResults[len(previousResults)-1]
	lines := strings.Split(discoveredLine, "\n")

	for _, line := range lines {
		filePath := strings.TrimSpace(line)
		if filePath == "" || strings.HasPrefix(filePath, "Discovered") || filePath == "No files found matching the criteria." {
			continue
		}

		fmt.Printf("   Refactoring %s...\n", filePath)

		content, err := os.ReadFile(filePath)
		if err != nil {
			fmt.Printf("   ❌ Could not read %s\n", filePath)
			continue
		}

		prompt := fmt.Sprintf(`Refactor the following file to use Result[T] instead of naked errors.
Follow existing style and preserve all comments.
Return ONLY this exact JSON (no extra text, no markdown):

{
  "file": "%s",
  "content": "the complete refactored file here"
}

Original file:
%s`, filePath, string(content))

		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()

		*refactorJSONs = append(*refactorJSONs, response)
	}
}

type FileChange struct {
	File    string `json:"file"`
	Content string `json:"content"`
}

func (r *Runner) handleApplyStep(refactorJSONs []string) {
	if len(refactorJSONs) == 0 {
		fmt.Println("   ⚠️  No refactored files to apply — skipping.")
		return
	}

	var allChanges []FileChange
	for _, jsonStr := range refactorJSONs {
		start := strings.Index(jsonStr, "{")
		end := strings.LastIndex(jsonStr, "}") + 1
		if start == -1 {
			continue
		}

		var ch FileChange
		if err := json.Unmarshal([]byte(jsonStr[start:end]), &ch); err == nil && ch.File != "" {
			allChanges = append(allChanges, ch)
		}
	}

	if len(allChanges) == 0 {
		fmt.Println("   ⚠️  No valid file changes found — skipping.")
		return
	}

	fmt.Println("   📄 Dry-run mode: creating patch file...")
	patchPath := filepath.Join(".", "recipe-refactor.patch")
	if err := createUnifiedPatch(allChanges, 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.")
}

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

	for _, ch := range changes {
		_, err := fmt.Fprintf(f, "--- %s\n+++ %s\n@@ -0,0 +1,%d @@\n", ch.File, ch.File, strings.Count(ch.Content, "\n")+1)
		if err != nil {
			return err
		}
		for _, line := range strings.Split(ch.Content, "\n") {
			_, err := fmt.Fprintf(f, "+%s\n", line)
			if err != nil {
				return err
			}
		}
	}
	return nil
}

// executeShellCommands — safe, whitelisted, boundary-enforced
// executeShellCommands — safe, whitelisted, boundary-enforced
func (r *Runner) executeShellCommands(step Step, previousResults []string, workDir string) {
	prompt := fmt.Sprintf(`You are executing shell commands for this step.

Project root (current working directory for all commands): %s

Previous step results:
%s

=== CURRENT STEP ===
Objective: %s
Instructions: %s

Return ONLY a JSON array of commands. Use **relative paths only** (no ~, no absolute paths). Example:

[
  {
    "command": "poetry",
    "args": ["new", "."]
  }
]

Never use cd, rm -rf, or anything that could escape the project directory.`,
		workDir,
		strings.Join(previousResults, "\n\n---\n\n"),
		step.Objective,
		step.Instructions)

	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()

	type ShellCommand struct {
		Command string   `json:"command"`
		Args    []string `json:"args"`
	}

	var cmds []ShellCommand
	start := strings.Index(response, "[")
	end := strings.LastIndex(response, "]") + 1
	if start == -1 {
		fmt.Println("   ⚠️  No valid shell commands returned — skipping.")
		return
	}

	if err := json.Unmarshal([]byte(response[start:end]), &cmds); err != nil {
		fmt.Printf("   ⚠️  Could not parse shell commands: %v\n", err)
		return
	}

	for _, cmd := range cmds {
		fullCmd := cmd.Command
		if len(cmd.Args) > 0 {
			fullCmd += " " + strings.Join(cmd.Args, " ")
		}

		fmt.Printf("   Running: %s\n", fullCmd)

		// Whitelist check
		allowed := false
		for _, allowedCmd := range r.Recipe.AllowedShellCommands {
			if strings.HasPrefix(cmd.Command, allowedCmd) {
				allowed = true
				break
			}
		}
		if !allowed {
			fmt.Printf("   ❌ Command not allowed: %s\n", cmd.Command)
			continue
		}

		// Safety check: no escaping the boundary
		for _, arg := range cmd.Args {
			if strings.Contains(arg, "..") || strings.HasPrefix(arg, "/") {
				fmt.Printf("   ❌ Command rejected (tries to escape boundary): %s\n", fullCmd)
				continue
			}
		}

		// Execute with strict cwd
		execCmd := exec.Command(cmd.Command, cmd.Args...)
		execCmd.Dir = workDir
		output, err := execCmd.CombinedOutput()

		if err != nil {
			fmt.Printf("   ❌ Failed: %v\n%s\n", err, string(output))
		} else {
			fmt.Printf("   ✅ Success\n%s\n", string(output))
		}
	}
}