package llm

import (
	"fmt"
	"strings"
)

// BuildPrompt builds a prompt from components
func BuildPrompt(tenantConfig *TenantConfig, conversationHistory []Message, userInput string, retrievedDocs []RetrievedDoc) string {
	var parts []string

	// System message
	systemMsg := buildSystemMessage(tenantConfig)
	parts = append(parts, systemMsg)

	// Retrieved documents (RAG context)
	if len(retrievedDocs) > 0 {
		parts = append(parts, "\n## Context:")
		for i, doc := range retrievedDocs {
			parts = append(parts, fmt.Sprintf("\n[Document %d]", i+1))
			parts = append(parts, fmt.Sprintf("Title: %s", doc.Title))
			parts = append(parts, fmt.Sprintf("Content: %s", doc.Content))
			if doc.URL != "" {
				parts = append(parts, fmt.Sprintf("Source: %s", doc.URL))
			}
		}
	}

	// Conversation history
	if len(conversationHistory) > 0 {
		parts = append(parts, "\n## Conversation History:")
		for _, msg := range conversationHistory {
			parts = append(parts, fmt.Sprintf("%s: %s", strings.Title(msg.Role), msg.Content))
		}
	}

	// Current user input
	parts = append(parts, fmt.Sprintf("\n## User: %s", userInput))
	parts = append(parts, "\n## Assistant:")

	return strings.Join(parts, "\n")
}

// TenantConfig holds tenant-specific configuration
type TenantConfig struct {
	Greeting     string
	Tone         string // "professional", "friendly", "formal"
	Disclaimers  []string
	AllowedTools []string
}

// RetrievedDoc represents a retrieved document from RAG
type RetrievedDoc struct {
	Title   string
	Content string
	URL     string
	Score   float64
}

// BuildPromptWithRAG builds a prompt with RAG context
func BuildPromptWithRAG(tenantConfig *TenantConfig, conversationHistory []Message, userInput string, retrievedDocs []RetrievedDoc) string {
	var parts []string

	// System message
	systemMsg := buildSystemMessage(tenantConfig)
	parts = append(parts, systemMsg)

	// Retrieved documents (RAG context)
	if len(retrievedDocs) > 0 {
		parts = append(parts, "\n## Context:")
		for i, doc := range retrievedDocs {
			parts = append(parts, fmt.Sprintf("\n[Document %d]", i+1))
			parts = append(parts, fmt.Sprintf("Title: %s", doc.Title))
			parts = append(parts, fmt.Sprintf("Content: %s", doc.Content))
			if doc.URL != "" {
				parts = append(parts, fmt.Sprintf("Source: %s", doc.URL))
			}
		}
	}

	// Conversation history
	if len(conversationHistory) > 0 {
		parts = append(parts, "\n## Conversation History:")
		for _, msg := range conversationHistory {
			parts = append(parts, fmt.Sprintf("%s: %s", strings.Title(msg.Role), msg.Content))
		}
	}

	// Current user input
	parts = append(parts, fmt.Sprintf("\n## User: %s", userInput))
	parts = append(parts, "\n## Assistant:")

	return strings.Join(parts, "\n")
}

// buildSystemMessage builds the system message
func buildSystemMessage(config *TenantConfig) string {
	var parts []string

	parts = append(parts, "You are a helpful Virtual Banker assistant.")

	if config.Tone != "" {
		parts = append(parts, fmt.Sprintf("Your tone should be %s.", config.Tone))
	}

	if len(config.Disclaimers) > 0 {
		parts = append(parts, "\nImportant disclaimers:")
		for _, disclaimer := range config.Disclaimers {
			parts = append(parts, fmt.Sprintf("- %s", disclaimer))
		}
	}

	if len(config.AllowedTools) > 0 {
		parts = append(parts, "\nYou have access to the following tools:")
		for _, tool := range config.AllowedTools {
			parts = append(parts, fmt.Sprintf("- %s", tool))
		}
	}

	parts = append(parts, "\nAlways be helpful, accurate, and respectful.")
	parts = append(parts, "If you don't know something, say so and offer to help find the answer.")

	return strings.Join(parts, "\n")
}