package execution

import (
	"fmt"
	"strings"
)

const (
	// ImageRegistry is the default registry for CHORUS development images
	ImageRegistry = "anthonyrawlins"

	// ImageVersion is the default version tag to use
	ImageVersion = "latest"
)

// ImageSelector maps task languages and contexts to appropriate development images
type ImageSelector struct {
	registry string
	version  string
}

// NewImageSelector creates a new image selector with default settings
func NewImageSelector() *ImageSelector {
	return &ImageSelector{
		registry: ImageRegistry,
		version:  ImageVersion,
	}
}

// NewImageSelectorWithConfig creates an image selector with custom registry and version
func NewImageSelectorWithConfig(registry, version string) *ImageSelector {
	if registry == "" {
		registry = ImageRegistry
	}
	if version == "" {
		version = ImageVersion
	}
	return &ImageSelector{
		registry: registry,
		version:  version,
	}
}

// SelectImage returns the appropriate image name for a given language
func (s *ImageSelector) SelectImage(language string) string {
	imageMap := map[string]string{
		"rust":       "chorus-rust-dev",
		"go":         "chorus-go-dev",
		"golang":     "chorus-go-dev",
		"python":     "chorus-python-dev",
		"py":         "chorus-python-dev",
		"javascript": "chorus-node-dev",
		"js":         "chorus-node-dev",
		"typescript": "chorus-node-dev",
		"ts":         "chorus-node-dev",
		"node":       "chorus-node-dev",
		"nodejs":     "chorus-node-dev",
		"java":       "chorus-java-dev",
		"cpp":        "chorus-cpp-dev",
		"c++":        "chorus-cpp-dev",
		"c":          "chorus-cpp-dev",
	}

	normalizedLang := strings.ToLower(strings.TrimSpace(language))

	if img, ok := imageMap[normalizedLang]; ok {
		return fmt.Sprintf("%s/%s:%s", s.registry, img, s.version)
	}

	// Default to base image if language not recognized
	return fmt.Sprintf("%s/chorus-base:%s", s.registry, s.version)
}

// DetectLanguage analyzes task context to determine primary programming language
func (s *ImageSelector) DetectLanguage(task *TaskExecutionRequest) string {
	// Priority 1: Explicit language specification
	if lang, ok := task.Context["language"].(string); ok && lang != "" {
		return strings.ToLower(strings.TrimSpace(lang))
	}

	// Priority 2: Language hint in requirements
	if task.Requirements != nil && task.Requirements.AIModel != "" {
		// Some models might hint at language in their name
		modelLang := extractLanguageFromModel(task.Requirements.AIModel)
		if modelLang != "" {
			return modelLang
		}
	}

	// Priority 3: Repository URL analysis
	if repoURL, ok := task.Context["repository_url"].(string); ok && repoURL != "" {
		return detectLanguageFromRepo(repoURL)
	}

	// Priority 4: Description keyword analysis
	return detectLanguageFromDescription(task.Description)
}

// SelectImageForTask is a convenience method that detects language and returns appropriate image
func (s *ImageSelector) SelectImageForTask(task *TaskExecutionRequest) string {
	language := s.DetectLanguage(task)
	return s.SelectImage(language)
}

// detectLanguageFromDescription analyzes task description for language keywords
func detectLanguageFromDescription(description string) string {
	desc := strings.ToLower(description)

	// Keyword map with priority (specific keywords beat generic ones)
	keywords := []struct {
		language string
		patterns []string
		priority int
	}{
		// High priority - specific language indicators
		{"rust", []string{"rust", "cargo.toml", ".rs file", "rustc", "cargo build"}, 3},
		{"go", []string{"golang", "go.mod", "go.sum", ".go file", "go build"}, 3},
		{"python", []string{"python3", "pip install", ".py file", "pytest", "requirements.txt", "pyproject.toml"}, 3},
		{"typescript", []string{"typescript", ".ts file", "tsconfig.json"}, 3},
		{"javascript", []string{"node.js", "npm install", "package.json", ".js file"}, 2},
		{"java", []string{"java", "maven", "gradle", "pom.xml", ".java file"}, 3},
		{"cpp", []string{"c++", "cmake", ".cpp file", ".cc file", "makefile"}, 3},

		// Medium priority - generic mentions
		{"rust", []string{"rust"}, 2},
		{"go", []string{"go "}, 2},
		{"python", []string{"python"}, 2},
		{"node", []string{"node ", "npm ", "yarn "}, 2},
		{"java", []string{"java "}, 2},
		{"cpp", []string{"c++ ", "cpp "}, 2},
		{"c", []string{" c "}, 1},
	}

	bestMatch := ""
	bestPriority := 0

	for _, kw := range keywords {
		for _, pattern := range kw.patterns {
			if strings.Contains(desc, pattern) {
				if kw.priority > bestPriority {
					bestMatch = kw.language
					bestPriority = kw.priority
				}
				break
			}
		}
	}

	if bestMatch != "" {
		return bestMatch
	}

	return "base"
}

// detectLanguageFromRepo attempts to detect language from repository URL or name
func detectLanguageFromRepo(repoURL string) string {
	repo := strings.ToLower(repoURL)

	// Check for language-specific repository naming patterns
	patterns := map[string][]string{
		"rust":       {"-rs", ".rs", "rust-"},
		"go":         {"-go", ".go", "go-"},
		"python":     {"-py", ".py", "python-"},
		"javascript": {"-js", ".js", "node-"},
		"typescript": {"-ts", ".ts"},
		"java":       {"-java", ".java"},
		"cpp":        {"-cpp", ".cpp", "-cxx"},
	}

	for lang, pats := range patterns {
		for _, pat := range pats {
			if strings.Contains(repo, pat) {
				return lang
			}
		}
	}

	return "base"
}

// extractLanguageFromModel tries to extract language hints from model name
func extractLanguageFromModel(modelName string) string {
	model := strings.ToLower(modelName)

	// Some models are language-specific
	if strings.Contains(model, "codellama") {
		return "base" // CodeLlama is multi-language
	}
	if strings.Contains(model, "go") && strings.Contains(model, "coder") {
		return "go"
	}
	if strings.Contains(model, "rust") {
		return "rust"
	}
	if strings.Contains(model, "python") {
		return "python"
	}

	return ""
}

// GetAvailableImages returns a list of all available development images
func (s *ImageSelector) GetAvailableImages() []string {
	images := []string{"chorus-base", "chorus-rust-dev", "chorus-go-dev", "chorus-python-dev", "chorus-node-dev", "chorus-java-dev", "chorus-cpp-dev"}
	result := make([]string, len(images))

	for i, img := range images {
		result[i] = fmt.Sprintf("%s/%s:%s", s.registry, img, s.version)
	}

	return result
}

// GetImageInfo returns metadata about a specific image
func (s *ImageSelector) GetImageInfo(imageName string) map[string]string {
	infoMap := map[string]map[string]string{
		"chorus-base": {
			"description": "Base Debian development environment with common tools",
			"size":        "~643MB",
			"tools":       "git, curl, build-essential, vim, jq",
			"registry":    "docker.io/anthonyrawlins/chorus-base",
		},
		"chorus-rust-dev": {
			"description": "Rust development environment with cargo and tooling",
			"size":        "~2.42GB",
			"tools":       "rustc, cargo, clippy, rustfmt, ripgrep, fd-find",
			"registry":    "docker.io/anthonyrawlins/chorus-rust-dev",
		},
		"chorus-go-dev": {
			"description": "Go development environment with standard tooling",
			"size":        "~1GB",
			"tools":       "go1.22, gopls, delve, staticcheck, golangci-lint",
			"registry":    "docker.io/anthonyrawlins/chorus-go-dev",
		},
		"chorus-python-dev": {
			"description": "Python development environment with modern tooling",
			"size":        "~1.07GB",
			"tools":       "python3.11, uv, ruff, black, pytest, mypy",
			"registry":    "docker.io/anthonyrawlins/chorus-python-dev",
		},
		"chorus-node-dev": {
			"description": "Node.js development environment with package managers",
			"size":        "~982MB",
			"tools":       "node20, pnpm, yarn, typescript, eslint, prettier",
			"registry":    "docker.io/anthonyrawlins/chorus-node-dev",
		},
		"chorus-java-dev": {
			"description": "Java development environment with build tools",
			"size":        "~1.3GB",
			"tools":       "openjdk-17, maven, gradle",
			"registry":    "docker.io/anthonyrawlins/chorus-java-dev",
		},
		"chorus-cpp-dev": {
			"description": "C/C++ development environment with compilers and tools",
			"size":        "~1.63GB",
			"tools":       "gcc, g++, clang, cmake, ninja, gdb, valgrind",
			"registry":    "docker.io/anthonyrawlins/chorus-cpp-dev",
		},
	}

	return infoMap[imageName]
}