package config

import (
	"context"
	"errors"
	"fmt"
	"maps"
	"os"
	"os/exec"
	"runtime"
	"slices"
	"strings"
	"time"

	"github.com/ollama/ollama/api"
	"github.com/ollama/ollama/progress"
	"github.com/spf13/cobra"
)

// Runners execute the launching of a model with the integration - claude, codex
// Editors can edit config files (supports multi-model selection) - opencode, droid
// They are composable interfaces where in some cases an editor is also a runner - opencode, droid
// Runner can run an integration with a model.

type Runner interface {
	Run(model string, args []string) error
	// String returns the human-readable name of the integration
	String() string
}

// Editor can edit config files (supports multi-model selection)
type Editor interface {
	// Paths returns the paths to the config files for the integration
	Paths() []string
	// Edit updates the config files for the integration with the given models
	Edit(models []string) error
	// Models returns the models currently configured for the integration
	// TODO(parthsareen): add error return to Models()
	Models() []string
}

// AliasConfigurer can configure model aliases (e.g., for subagent routing).
// Integrations like Claude and Codex use this to route model requests to local models.
type AliasConfigurer interface {
	// ConfigureAliases prompts the user to configure aliases and returns the updated map.
	ConfigureAliases(ctx context.Context, primaryModel string, existing map[string]string, force bool) (map[string]string, bool, error)
	// SetAliases syncs the configured aliases to the server
	SetAliases(ctx context.Context, aliases map[string]string) error
}

// integrations is the registry of available integrations.
var integrations = map[string]Runner{
	"claude":   &Claude{},
	"clawdbot": &Openclaw{},
	"codex":    &Codex{},
	"moltbot":  &Openclaw{},
	"droid":    &Droid{},
	"opencode": &OpenCode{},
	"openclaw": &Openclaw{},
}

// recommendedModels are shown when the user has no models or as suggestions.
// Order matters: local models first, then cloud models.
var recommendedModels = []selectItem{
	{Name: "glm-4.7-flash", Description: "Recommended (requires ~25GB VRAM)"},
	{Name: "qwen3:8b", Description: "Recommended (requires ~11GB VRAM)"},
	{Name: "glm-4.7:cloud", Description: "Recommended"},
	{Name: "kimi-k2.5:cloud", Description: "Recommended"},
}

// integrationAliases are hidden from the interactive selector but work as CLI arguments.
var integrationAliases = map[string]bool{
	"clawdbot": true,
	"moltbot":  true,
}

func selectIntegration() (string, error) {
	if len(integrations) == 0 {
		return "", fmt.Errorf("no integrations available")
	}

	names := slices.Sorted(maps.Keys(integrations))
	var items []selectItem
	for _, name := range names {
		if integrationAliases[name] {
			continue
		}
		r := integrations[name]
		description := r.String()
		if conn, err := loadIntegration(name); err == nil && len(conn.Models) > 0 {
			description = fmt.Sprintf("%s (%s)", r.String(), conn.Models[0])
		}
		items = append(items, selectItem{Name: name, Description: description})
	}

	return selectPrompt("Select integration:", items)
}

// selectModels lets the user select models for an integration
func selectModels(ctx context.Context, name, current string) ([]string, error) {
	r, ok := integrations[name]
	if !ok {
		return nil, fmt.Errorf("unknown integration: %s", name)
	}

	client, err := api.ClientFromEnvironment()
	if err != nil {
		return nil, err
	}

	models, err := client.List(ctx)
	if err != nil {
		return nil, err
	}

	var existing []modelInfo
	for _, m := range models.Models {
		existing = append(existing, modelInfo{Name: m.Name, Remote: m.RemoteModel != ""})
	}

	var preChecked []string
	if saved, err := loadIntegration(name); err == nil {
		preChecked = saved.Models
	} else if editor, ok := r.(Editor); ok {
		preChecked = editor.Models()
	}

	items, preChecked, existingModels, cloudModels := buildModelList(existing, preChecked, current)

	if len(items) == 0 {
		return nil, fmt.Errorf("no models available")
	}

	var selected []string
	if _, ok := r.(Editor); ok {
		selected, err = multiSelectPrompt(fmt.Sprintf("Select models for %s:", r), items, preChecked)
		if err != nil {
			return nil, err
		}
	} else {
		prompt := fmt.Sprintf("Select model for %s:", r)
		if _, ok := r.(AliasConfigurer); ok {
			prompt = fmt.Sprintf("Select Primary model for %s:", r)
		}
		model, err := selectPrompt(prompt, items)
		if err != nil {
			return nil, err
		}
		selected = []string{model}
	}

	var toPull []string
	for _, m := range selected {
		if !existingModels[m] {
			toPull = append(toPull, m)
		}
	}
	if len(toPull) > 0 {
		msg := fmt.Sprintf("Download %s?", strings.Join(toPull, ", "))
		if ok, err := confirmPrompt(msg); err != nil {
			return nil, err
		} else if !ok {
			return nil, errCancelled
		}
		for _, m := range toPull {
			fmt.Fprintf(os.Stderr, "\n")
			if err := pullModel(ctx, client, m); err != nil {
				return nil, fmt.Errorf("failed to pull %s: %w", m, err)
			}
		}
	}

	if err := ensureAuth(ctx, client, cloudModels, selected); err != nil {
		return nil, err
	}

	return selected, nil
}

func pullIfNeeded(ctx context.Context, client *api.Client, existingModels map[string]bool, model string) error {
	if existingModels[model] {
		return nil
	}
	msg := fmt.Sprintf("Download %s?", model)
	if ok, err := confirmPrompt(msg); err != nil {
		return err
	} else if !ok {
		return errCancelled
	}
	fmt.Fprintf(os.Stderr, "\n")
	if err := pullModel(ctx, client, model); err != nil {
		return fmt.Errorf("failed to pull %s: %w", model, err)
	}
	return nil
}

func listModels(ctx context.Context) ([]selectItem, map[string]bool, map[string]bool, *api.Client, error) {
	client, err := api.ClientFromEnvironment()
	if err != nil {
		return nil, nil, nil, nil, err
	}

	models, err := client.List(ctx)
	if err != nil {
		return nil, nil, nil, nil, err
	}

	var existing []modelInfo
	for _, m := range models.Models {
		existing = append(existing, modelInfo{Name: m.Name, Remote: m.RemoteModel != ""})
	}

	items, _, existingModels, cloudModels := buildModelList(existing, nil, "")

	if len(items) == 0 {
		return nil, nil, nil, nil, fmt.Errorf("no models available, run 'ollama pull <model>' first")
	}

	return items, existingModels, cloudModels, client, nil
}

func ensureAuth(ctx context.Context, client *api.Client, cloudModels map[string]bool, selected []string) error {
	var selectedCloudModels []string
	for _, m := range selected {
		if cloudModels[m] {
			selectedCloudModels = append(selectedCloudModels, m)
		}
	}
	if len(selectedCloudModels) == 0 {
		return nil
	}

	user, err := client.Whoami(ctx)
	if err == nil && user != nil && user.Name != "" {
		return nil
	}

	var aErr api.AuthorizationError
	if !errors.As(err, &aErr) || aErr.SigninURL == "" {
		return err
	}

	modelList := strings.Join(selectedCloudModels, ", ")
	yes, err := confirmPrompt(fmt.Sprintf("sign in to use %s?", modelList))
	if err != nil || !yes {
		return fmt.Errorf("%s requires sign in", modelList)
	}

	fmt.Fprintf(os.Stderr, "\nTo sign in, navigate to:\n    %s\n\n", aErr.SigninURL)

	switch runtime.GOOS {
	case "darwin":
		_ = exec.Command("open", aErr.SigninURL).Start()
	case "linux":
		_ = exec.Command("xdg-open", aErr.SigninURL).Start()
	case "windows":
		_ = exec.Command("rundll32", "url.dll,FileProtocolHandler", aErr.SigninURL).Start()
	}

	spinnerFrames := []string{"|", "/", "-", "\\"}
	frame := 0

	fmt.Fprintf(os.Stderr, "\033[90mwaiting for sign in to complete... %s\033[0m", spinnerFrames[0])

	ticker := time.NewTicker(200 * time.Millisecond)
	defer ticker.Stop()

	for {
		select {
		case <-ctx.Done():
			fmt.Fprintf(os.Stderr, "\r\033[K")
			return ctx.Err()
		case <-ticker.C:
			frame++
			fmt.Fprintf(os.Stderr, "\r\033[90mwaiting for sign in to complete... %s\033[0m", spinnerFrames[frame%len(spinnerFrames)])

			// poll every 10th frame (~2 seconds)
			if frame%10 == 0 {
				u, err := client.Whoami(ctx)
				if err == nil && u != nil && u.Name != "" {
					fmt.Fprintf(os.Stderr, "\r\033[K\033[A\r\033[K\033[1msigned in:\033[0m %s\n", u.Name)
					return nil
				}
			}
		}
	}
}

func ensureAliases(ctx context.Context, r Runner, name string, primaryModel string, existing map[string]string, force bool) (bool, error) {
	ac, ok := r.(AliasConfigurer)
	if !ok {
		return false, nil
	}

	aliases, updated, err := ac.ConfigureAliases(ctx, primaryModel, existing, force)
	if err != nil {
		return false, err
	}
	if !updated {
		return false, nil
	}

	if err := saveAliases(name, aliases); err != nil {
		return false, err
	}

	if err := ac.SetAliases(ctx, aliases); err != nil {
		fmt.Fprintf(os.Stderr, "%sWarning: Could not sync aliases to server: %v%s\n", ansiGray, err, ansiReset)
		fmt.Fprintf(os.Stderr, "%sAliases saved locally. Server sync will retry on next launch.%s\n\n", ansiGray, ansiReset)
	}

	return true, nil
}

func runIntegration(name, modelName string, args []string) error {
	r, ok := integrations[name]
	if !ok {
		return fmt.Errorf("unknown integration: %s", name)
	}

	if _, ok := r.(AliasConfigurer); ok {
		if config, err := loadIntegration(name); err == nil && config.Aliases != nil {
			primary, fast := config.Aliases["primary"], config.Aliases["fast"]
			if primary != "" && fast != "" {
				fmt.Fprintf(os.Stderr, "\nLaunching %s with Primary: %s, Fast: %s...\n", r, primary, fast)
				return r.Run(modelName, args)
			}
		}
	}

	fmt.Fprintf(os.Stderr, "\nLaunching %s with %s...\n", r, modelName)
	return r.Run(modelName, args)
}

// LaunchCmd returns the cobra command for launching integrations.
func LaunchCmd(checkServerHeartbeat func(cmd *cobra.Command, args []string) error) *cobra.Command {
	var modelFlag string
	var configFlag bool

	cmd := &cobra.Command{
		Use:   "launch [INTEGRATION] [-- [EXTRA_ARGS...]]",
		Short: "Launch an integration with Ollama",
		Long: `Launch an integration configured with Ollama models.

Supported integrations:
  claude    Claude Code
  codex     Codex
  droid     Droid
  opencode  OpenCode
  openclaw  OpenClaw (aliases: clawdbot, moltbot)

Examples:
  ollama launch
  ollama launch claude
  ollama launch claude --model <model>
  ollama launch droid --config (does not auto-launch)
  ollama launch codex -- -p myprofile (pass extra args to integration)
  ollama launch codex -- --sandbox workspace-write`,
		Args:    cobra.ArbitraryArgs,
		PreRunE: checkServerHeartbeat,
		RunE: func(cmd *cobra.Command, args []string) error {
			// Extract integration name and args to pass through using -- separator
			var name string
			var passArgs []string
			dashIdx := cmd.ArgsLenAtDash()

			if dashIdx == -1 {
				// No "--" separator: only allow 0 or 1 args (integration name)
				if len(args) > 1 {
					return fmt.Errorf("unexpected arguments: %v\nUse '--' to pass extra arguments to the integration", args[1:])
				}
				if len(args) == 1 {
					name = args[0]
				}
			} else {
				// "--" was used: args before it = integration name, args after = passthrough
				if dashIdx > 1 {
					return fmt.Errorf("expected at most 1 integration name before '--', got %d", dashIdx)
				}
				if dashIdx == 1 {
					name = args[0]
				}
				passArgs = args[dashIdx:]
			}

			if name == "" {
				var err error
				name, err = selectIntegration()
				if errors.Is(err, errCancelled) {
					return nil
				}
				if err != nil {
					return err
				}
			}

			r, ok := integrations[strings.ToLower(name)]
			if !ok {
				return fmt.Errorf("unknown integration: %s", name)
			}

			if !configFlag && modelFlag == "" {
				if config, err := loadIntegration(name); err == nil && len(config.Models) > 0 {
					if _, err := ensureAliases(cmd.Context(), r, name, config.Models[0], config.Aliases, false); errors.Is(err, errCancelled) {
						return nil
					} else if err != nil {
						return err
					}
					return runIntegration(name, config.Models[0], passArgs)
				}
			}

			if ac, ok := r.(AliasConfigurer); ok {
				var existingAliases map[string]string
				if existing, err := loadIntegration(name); err == nil {
					existingAliases = existing.Aliases
				}
				aliases, updated, err := ac.ConfigureAliases(cmd.Context(), "", existingAliases, configFlag)
				if errors.Is(err, errCancelled) {
					return nil
				}
				if err != nil {
					return err
				}
				if updated {
					if err := saveAliases(name, aliases); err != nil {
						return err
					}
					if err := ac.SetAliases(cmd.Context(), aliases); err != nil {
						fmt.Fprintf(os.Stderr, "%sWarning: Could not sync aliases to server: %v%s\n", ansiGray, err, ansiReset)
					}
					fmt.Fprintf(os.Stderr, "\n%sConfiguration Complete%s\n", ansiBold, ansiReset)
					fmt.Fprintf(os.Stderr, "Primary: %s\n", aliases["primary"])
					fmt.Fprintf(os.Stderr, "Fast: %s\n\n", aliases["fast"])
				}
				if err := saveIntegration(name, []string{aliases["primary"]}); err != nil {
					return fmt.Errorf("failed to save: %w", err)
				}
				if configFlag {
					if launch, _ := confirmPrompt(fmt.Sprintf("Launch %s now?", r)); launch {
						return runIntegration(name, aliases["primary"], passArgs)
					}
					return nil
				}
				return runIntegration(name, aliases["primary"], passArgs)
			}

			var models []string
			if modelFlag != "" {
				models = []string{modelFlag}
				if existing, err := loadIntegration(name); err == nil && len(existing.Models) > 0 {
					for _, m := range existing.Models {
						if m != modelFlag {
							models = append(models, m)
						}
					}
				}
			} else {
				var err error
				models, err = selectModels(cmd.Context(), name, "")
				if errors.Is(err, errCancelled) {
					return nil
				}
				if err != nil {
					return err
				}
			}

			if editor, isEditor := r.(Editor); isEditor {
				paths := editor.Paths()
				if len(paths) > 0 {
					fmt.Fprintf(os.Stderr, "This will modify your %s configuration:\n", r)
					for _, p := range paths {
						fmt.Fprintf(os.Stderr, "  %s\n", p)
					}
					fmt.Fprintf(os.Stderr, "Backups will be saved to %s/\n\n", backupDir())

					if ok, _ := confirmPrompt("Proceed?"); !ok {
						return nil
					}
				}
			}

			if err := saveIntegration(name, models); err != nil {
				return fmt.Errorf("failed to save: %w", err)
			}

			if editor, isEditor := r.(Editor); isEditor {
				if err := editor.Edit(models); err != nil {
					return fmt.Errorf("setup failed: %w", err)
				}
			}

			if _, isEditor := r.(Editor); isEditor {
				if len(models) == 1 {
					fmt.Fprintf(os.Stderr, "Added %s to %s\n", models[0], r)
				} else {
					fmt.Fprintf(os.Stderr, "Added %d models to %s (default: %s)\n", len(models), r, models[0])
				}
			}

			if configFlag {
				if launch, _ := confirmPrompt(fmt.Sprintf("\nLaunch %s now?", r)); launch {
					return runIntegration(name, models[0], passArgs)
				}
				fmt.Fprintf(os.Stderr, "Run 'ollama launch %s' to start with %s\n", strings.ToLower(name), models[0])
				return nil
			}

			return runIntegration(name, models[0], passArgs)
		},
	}

	cmd.Flags().StringVar(&modelFlag, "model", "", "Model to use")
	cmd.Flags().BoolVar(&configFlag, "config", false, "Configure without launching")
	return cmd
}

type modelInfo struct {
	Name   string
	Remote bool
}

// buildModelList merges existing models with recommendations, sorts them, and returns
// the ordered items along with maps of existing and cloud model names.
func buildModelList(existing []modelInfo, preChecked []string, current string) (items []selectItem, orderedChecked []string, existingModels, cloudModels map[string]bool) {
	existingModels = make(map[string]bool)
	cloudModels = make(map[string]bool)
	recommended := make(map[string]bool)
	var hasLocalModel, hasCloudModel bool

	for _, rec := range recommendedModels {
		recommended[rec.Name] = true
	}

	for _, m := range existing {
		existingModels[m.Name] = true
		if m.Remote {
			cloudModels[m.Name] = true
			hasCloudModel = true
		} else {
			hasLocalModel = true
		}
		displayName := strings.TrimSuffix(m.Name, ":latest")
		existingModels[displayName] = true
		item := selectItem{Name: displayName}
		if recommended[displayName] {
			item.Description = "recommended"
		}
		items = append(items, item)
	}

	for _, rec := range recommendedModels {
		if existingModels[rec.Name] || existingModels[rec.Name+":latest"] {
			continue
		}
		items = append(items, rec)
		if isCloudModel(rec.Name) {
			cloudModels[rec.Name] = true
		}
	}

	checked := make(map[string]bool, len(preChecked))
	for _, n := range preChecked {
		checked[n] = true
	}

	// Resolve current to full name (e.g., "llama3.2" -> "llama3.2:latest")
	for _, item := range items {
		if item.Name == current || strings.HasPrefix(item.Name, current+":") {
			current = item.Name
			break
		}
	}

	if checked[current] {
		preChecked = append([]string{current}, slices.DeleteFunc(preChecked, func(m string) bool { return m == current })...)
	}

	// Non-existing models get "install?" suffix and are pushed to the bottom.
	// When user has no models, preserve recommended order.
	notInstalled := make(map[string]bool)
	for i := range items {
		if !existingModels[items[i].Name] {
			notInstalled[items[i].Name] = true
			if items[i].Description != "" {
				items[i].Description += ", install?"
			} else {
				items[i].Description = "install?"
			}
		}
	}

	if hasLocalModel || hasCloudModel {
		slices.SortStableFunc(items, func(a, b selectItem) int {
			ac, bc := checked[a.Name], checked[b.Name]
			aNew, bNew := notInstalled[a.Name], notInstalled[b.Name]

			if ac != bc {
				if ac {
					return -1
				}
				return 1
			}
			if !ac && !bc && aNew != bNew {
				if aNew {
					return 1
				}
				return -1
			}
			return strings.Compare(strings.ToLower(a.Name), strings.ToLower(b.Name))
		})
	}

	return items, preChecked, existingModels, cloudModels
}

func isCloudModel(name string) bool {
	return strings.HasSuffix(name, ":cloud")
}

func pullModel(ctx context.Context, client *api.Client, model string) error {
	p := progress.NewProgress(os.Stderr)
	defer p.Stop()

	bars := make(map[string]*progress.Bar)
	var status string
	var spinner *progress.Spinner

	fn := func(resp api.ProgressResponse) error {
		if resp.Digest != "" {
			if resp.Completed == 0 {
				return nil
			}

			if spinner != nil {
				spinner.Stop()
			}

			bar, ok := bars[resp.Digest]
			if !ok {
				name, isDigest := strings.CutPrefix(resp.Digest, "sha256:")
				name = strings.TrimSpace(name)
				if isDigest {
					name = name[:min(12, len(name))]
				}
				bar = progress.NewBar(fmt.Sprintf("pulling %s:", name), resp.Total, resp.Completed)
				bars[resp.Digest] = bar
				p.Add(resp.Digest, bar)
			}

			bar.Set(resp.Completed)
		} else if status != resp.Status {
			if spinner != nil {
				spinner.Stop()
			}

			status = resp.Status
			spinner = progress.NewSpinner(status)
			p.Add(status, spinner)
		}

		return nil
	}

	request := api.PullRequest{Name: model}
	return client.Pull(ctx, &request, fn)
}