package main

import (
	"fmt"
	"strings"

	"github.com/charmbracelet/lipgloss"

	llm "gitea.stevedudenhoeffer.com/steve/go-llm"
)

// View renders the current state
func (m Model) View() string {
	switch m.state {
	case StateProviderSelect:
		return m.renderProviderSelect()
	case StateModelSelect:
		return m.renderModelSelect()
	case StateImageInput:
		return m.renderImageInput()
	case StateToolsPanel:
		return m.renderToolsPanel()
	case StateSettings:
		return m.renderSettings()
	case StateAPIKeyInput:
		return m.renderAPIKeyInput()
	default:
		return m.renderChat()
	}
}

// renderChat renders the main chat view
func (m Model) renderChat() string {
	var b strings.Builder

	// Header
	provider := m.providerName
	if provider == "" {
		provider = "None"
	}
	model := m.modelName
	if model == "" {
		model = "None"
	}

	header := headerStyle.Render(fmt.Sprintf("go-llm CLI  %s",
		providerBadgeStyle.Render(fmt.Sprintf("%s/%s", provider, model))))

	b.WriteString(header)
	b.WriteString("\n")

	// Messages viewport
	if m.viewportReady {
		b.WriteString(m.viewport.View())
		b.WriteString("\n")
	}

	// Image indicator
	if len(m.pendingImages) > 0 {
		b.WriteString(imageIndicatorStyle.Render(fmt.Sprintf(" [%d image(s) attached]", len(m.pendingImages))))
		b.WriteString("\n")
	}

	// Error
	if m.err != nil {
		b.WriteString(errorStyle.Render(" Error: " + m.err.Error()))
		b.WriteString("\n")
	}

	// Loading
	if m.loading {
		b.WriteString(loadingStyle.Render(" Thinking..."))
		b.WriteString("\n")
	}

	// Input
	inputBox := inputStyle.Render(m.input.View())
	b.WriteString(inputBox)
	b.WriteString("\n")

	// Help
	help := inputHelpStyle.Render("Enter: send | Ctrl+I: image | Ctrl+T: tools | Ctrl+P: provider | Ctrl+M: model | Ctrl+S: settings | Ctrl+N: new | Esc: quit")
	b.WriteString(help)

	return appStyle.Render(b.String())
}

// renderMessages renders all messages for the viewport
func (m Model) renderMessages() string {
	var b strings.Builder

	if len(m.messages) == 0 {
		b.WriteString(systemMsgStyle.Render("[System] " + m.systemPrompt))
		b.WriteString("\n\n")
		b.WriteString(lipgloss.NewStyle().Foreground(mutedColor).Render("Start a conversation by typing a message below."))
		return b.String()
	}

	b.WriteString(systemMsgStyle.Render("[System] " + m.systemPrompt))
	b.WriteString("\n\n")

	for _, msg := range m.messages {
		var content string
		var style lipgloss.Style

		switch msg.Role {
		case llm.RoleUser:
			style = userMsgStyle
			label := roleLabelStyle.Foreground(secondaryColor).Render("[User]")
			content = label + " " + msg.Content
			if msg.Images > 0 {
				content += imageIndicatorStyle.Render(fmt.Sprintf(" [%d image(s)]", msg.Images))
			}
		case llm.RoleAssistant:
			style = assistantMsgStyle
			label := roleLabelStyle.Foreground(lipgloss.Color("255")).Render("[Assistant]")
			content = label + " " + msg.Content
		case llm.Role("tool_call"):
			style = toolCallStyle
			content = "  -> Calling: " + msg.Content
		case llm.Role("tool_result"):
			style = toolResultStyle
			content = "  <- Result: " + msg.Content
		default:
			style = assistantMsgStyle
			content = msg.Content
		}

		b.WriteString(style.Render(content))
		b.WriteString("\n\n")
	}

	return b.String()
}

// renderProviderSelect renders the provider selection view
func (m Model) renderProviderSelect() string {
	var b strings.Builder

	b.WriteString(headerStyle.Render("Select Provider"))
	b.WriteString("\n\n")

	for i, item := range m.listItems {
		cursor := "  "
		style := normalItemStyle
		if i == m.listIndex {
			cursor = "> "
			style = selectedItemStyle
		}
		b.WriteString(style.Render(cursor + item))
		b.WriteString("\n")
	}

	b.WriteString("\n")
	b.WriteString(helpStyle.Render("Use arrow keys or j/k to navigate, Enter to select, Esc to cancel"))

	return appStyle.Render(b.String())
}

// renderAPIKeyInput renders the API key input view
func (m Model) renderAPIKeyInput() string {
	var b strings.Builder

	provider := m.providers[m.listIndex]

	b.WriteString(headerStyle.Render(fmt.Sprintf("Enter API Key for %s", provider.Name)))
	b.WriteString("\n\n")

	b.WriteString(fmt.Sprintf("Environment variable: %s\n\n", provider.EnvVar))
	b.WriteString("Enter your API key below (it will be hidden):\n\n")

	inputBox := inputStyle.Render(m.apiKeyInput.View())
	b.WriteString(inputBox)
	b.WriteString("\n\n")

	b.WriteString(helpStyle.Render("Enter to confirm, Esc to cancel"))

	return appStyle.Render(b.String())
}

// renderModelSelect renders the model selection view
func (m Model) renderModelSelect() string {
	var b strings.Builder

	b.WriteString(headerStyle.Render(fmt.Sprintf("Select Model (%s)", m.providerName)))
	b.WriteString("\n\n")

	for i, item := range m.listItems {
		cursor := "  "
		style := normalItemStyle
		if i == m.listIndex {
			cursor = "> "
			style = selectedItemStyle
		}
		if item == m.modelName {
			item += " (current)"
		}
		b.WriteString(style.Render(cursor + item))
		b.WriteString("\n")
	}

	b.WriteString("\n")
	b.WriteString(helpStyle.Render("Use arrow keys or j/k to navigate, Enter to select, Esc to cancel"))

	return appStyle.Render(b.String())
}

// renderImageInput renders the image input view
func (m Model) renderImageInput() string {
	var b strings.Builder

	b.WriteString(headerStyle.Render("Add Image"))
	b.WriteString("\n\n")

	b.WriteString("Enter an image source:\n")
	b.WriteString("  - File path (e.g., /path/to/image.png)\n")
	b.WriteString("  - URL (e.g., https://example.com/image.jpg)\n")
	b.WriteString("  - Base64 data or data URL\n\n")

	if len(m.pendingImages) > 0 {
		b.WriteString(imageIndicatorStyle.Render(fmt.Sprintf("Currently attached: %d image(s)\n\n", len(m.pendingImages))))
	}

	inputBox := inputStyle.Render(m.input.View())
	b.WriteString(inputBox)
	b.WriteString("\n\n")

	b.WriteString(helpStyle.Render("Enter to add image, Esc to cancel"))

	return appStyle.Render(b.String())
}

// renderToolsPanel renders the tools panel
func (m Model) renderToolsPanel() string {
	var b strings.Builder

	b.WriteString(headerStyle.Render("Tools / Function Calling"))
	b.WriteString("\n\n")

	status := "DISABLED"
	statusStyle := errorStyle
	if m.toolsEnabled {
		status = "ENABLED"
		statusStyle = lipgloss.NewStyle().Foreground(successColor).Bold(true)
	}

	b.WriteString(settingLabelStyle.Render("Tools Status:"))
	b.WriteString(statusStyle.Render(status))
	b.WriteString("\n\n")

	b.WriteString("Available tools:\n")
	for _, fn := range m.toolbox.Functions() {
		b.WriteString(fmt.Sprintf("  - %s: %s\n", selectedItemStyle.Render(fn.Name), fn.Description))
	}

	b.WriteString("\n")
	b.WriteString(helpStyle.Render("Press 't' to toggle tools, Enter or 'q' to close"))

	return appStyle.Render(b.String())
}

// renderSettings renders the settings view
func (m Model) renderSettings() string {
	var b strings.Builder

	b.WriteString(headerStyle.Render("Settings"))
	b.WriteString("\n\n")

	// Temperature
	tempStr := "default"
	if m.temperature != nil {
		tempStr = fmt.Sprintf("%.1f", *m.temperature)
	}
	b.WriteString(settingLabelStyle.Render("Temperature:"))
	b.WriteString(settingValueStyle.Render(tempStr))
	b.WriteString("\n\n")

	b.WriteString("Press a key to set temperature:\n")
	b.WriteString("  1 - Default (model decides)\n")
	b.WriteString("  2 - 0.0 (deterministic)\n")
	b.WriteString("  3 - 0.5 (balanced)\n")
	b.WriteString("  4 - 0.7 (creative)\n")
	b.WriteString("  5 - 1.0 (very creative)\n")

	b.WriteString("\n")

	// System prompt
	b.WriteString(settingLabelStyle.Render("System Prompt:"))
	b.WriteString("\n")
	b.WriteString(settingValueStyle.Render("  " + m.systemPrompt))
	b.WriteString("\n\n")

	b.WriteString(helpStyle.Render("Enter or 'q' to close"))

	return appStyle.Render(b.String())
}