package recipe

import (
	"bytes"
	"fmt"
	"os"
	"path/filepath"
	"regexp"
	"strings"
	"sync"
	"text/template"

	"gopkg.in/yaml.v3"
)

// Global safe read-only whitelist
// LoadSafeCommands reads the user's safe shell commands config (with fallback)
var safeCommands = sync.OnceValue(func() map[string]bool {
	cfgPath := filepath.Join(os.Getenv("HOME"), ".config", "grokkit", "safe_shell_commands.yaml")

	data, err := os.ReadFile(cfgPath)
	if err != nil {
		// Fallback to a built-in safe list
		fmt.Println("Could not read safe shell commands config, using built-in fallback")
		return map[string]bool{
			"ls": true, "pwd": true, "cat": true, "tree": true,
			"find": true, "grep": true, "rg": true,
			"git status": true, "git log": true, "git diff": true, "git branch": true,
			"go test": true, "go vet": true, "go fmt": true, "go mod tidy": true,
			"make test": true,
			"pytest":    true, "poetry run pytest": true, "ctest": true,
			"python -m pytest": true, "python": true, "poetry": true,
		}

	}
	fmt.Println("Using safe shell commands config:", cfgPath)

	var cfg struct {
		SafeCommands []string `yaml:"safe_commands"`
	}
	err = yaml.Unmarshal(data, &cfg)
	if err != nil {
		return nil
	}

	m := make(map[string]bool)
	for _, c := range cfg.SafeCommands {
		m[strings.ToLower(strings.TrimSpace(c))] = true
	}
	return m
})

var (
	// stepRe still finds the headings (this one is solid)
	stepRe = regexp.MustCompile(`(?m)^### Step (\d+): (.+)$`)
)

func Load(path string, userParams map[string]any) (*Recipe, error) {
	b, err := os.ReadFile(path)
	if err != nil {
		return nil, err
	}

	parts := bytes.SplitN(b, []byte("---"), 3)
	if len(parts) < 3 {
		return nil, fmt.Errorf("missing YAML frontmatter")
	}

	var r Recipe
	if err := yaml.Unmarshal(parts[1], &r); err != nil {
		return nil, fmt.Errorf("yaml parse: %w", err)
	}

	// === SAFETY CHECK using user-configurable whitelist ===
	safeMap := safeCommands()
	for _, cmd := range r.AllowedShellCommands {
		trimmed := strings.ToLower(strings.TrimSpace(cmd))

		allowed := false
		for safe := range safeMap {
			safeTrim := strings.ToLower(strings.TrimSpace(safe))

			// Match exact command OR command followed by space + arguments
			if trimmed == safeTrim || strings.HasPrefix(trimmed, safeTrim+" ") {
				allowed = true
				break
			}
		}
		if !allowed {
			return nil, fmt.Errorf("\u001B[31mRecipe contains unsafe shell command: %q. "+
				"Remove or replace the dangerous command in your recipe.\u001B[0m", cmd)
		}
	}

	// Apply defaults + user --param overrides
	if r.Parameters == nil {
		r.Parameters = make(map[string]Parameter)
	}
	r.ResolvedParams = make(map[string]any)
	for name, p := range r.Parameters {
		if v, ok := userParams[name]; ok {
			r.ResolvedParams[name] = v
		} else if p.Default != nil {
			r.ResolvedParams[name] = p.Default
		}
	}

	// Render templates with resolved values
	tpl, err := template.New("recipe").Parse(string(parts[2]))
	if err != nil {
		return nil, err
	}
	var rendered bytes.Buffer
	if err := tpl.Execute(&rendered, r.ResolvedParams); err != nil {
		return nil, err
	}
	body := rendered.String()

	// Extract Overview
	if idx := strings.Index(body, "## Execution Steps"); idx != -1 {
		r.Overview = strings.TrimSpace(body[:idx])
	}

	// Extract steps with robust multi-line parsing
	matches := stepRe.FindAllStringSubmatch(body, -1)
	for i, m := range matches {
		stepNum := i + 1
		title := m[2]

		start := strings.Index(body, m[0])
		end := len(body)
		if i+1 < len(matches) {
			nextStart := strings.Index(body[start:], matches[i+1][0])
			end = start + nextStart
		}

		section := body[start:end]

		step := Step{Number: stepNum, Title: title}

		// Simple, reliable label-based parsing (handles multi-line + blank lines)
		labels := []string{"**Objective:**", "**Instructions:**", "**Expected output:**"}
		for _, label := range labels {
			labelStart := strings.Index(section, label)
			if labelStart == -1 {
				continue
			}
			contentStart := labelStart + len(label)
			contentEnd := len(section)

			// Find next label or end of section
			for _, nextLabel := range labels {
				next := strings.Index(section[contentStart:], nextLabel)
				if next != -1 {
					contentEnd = contentStart + next
					break
				}
			}

			content := strings.TrimSpace(section[contentStart:contentEnd])

			switch label {
			case "**Objective:**":
				step.Objective = content
			case "**Instructions:**":
				step.Instructions = content
			case "**Expected output:**":
				step.Expected = content
			}
		}

		r.Steps = append(r.Steps, step)
	}

	// Final summary (everything after last step)
	if len(matches) > 0 {
		lastMatch := matches[len(matches)-1][0]
		lastIdx := strings.LastIndex(body, lastMatch)
		r.FinalSummaryPrompt = strings.TrimSpace(body[lastIdx+len(lastMatch):])
	}

	return &r, nil
}