package config

import (
	"errors"
	"fmt"
	"os"
	"path/filepath"
	"time"

	"github.com/BurntSushi/toml"
)

// Project represents a named workspace project used for webhook routing.
type Project struct {
	Name string `toml:"name"`
	Dir  string `toml:"dir"`
}

// LocalModel configures an OpenAI-compatible local LLM endpoint used for
// internal helpers (classifier, elaboration, future summarization) and as
// the backend for the "local" runner. If Endpoint is empty, the LocalRunner
// is not registered and the classifier falls back to the Gemini CLI.
//
// PreferForElaborate gates whether the API server's elaboration handler
// uses this client. It defaults to true when Endpoint is set; users with a
// slow or low-quality local model can disable it.
type LocalModel struct {
	Endpoint           string  `toml:"endpoint"`             // e.g. "http://localhost:11434/v1"
	Model              string  `toml:"model"`                // e.g. "llama3.1:8b"
	TimeoutSeconds     int     `toml:"timeout_seconds"`      // default 60
	DefaultTemperature float64 `toml:"default_temperature"`  // default 0.2
	APIKey             string  `toml:"api_key"`              // optional bearer token
	PreferForElaborate *bool   `toml:"prefer_for_elaborate"` // pointer so default-true survives parse
}

// UseForElaborate returns true when elaboration should try this local model
// before falling back to Claude/Gemini. Default is true when Endpoint is set.
func (m LocalModel) UseForElaborate() bool {
	if m.Endpoint == "" {
		return false
	}
	if m.PreferForElaborate == nil {
		return true
	}
	return *m.PreferForElaborate
}

// RunnersConfig controls which agent runners are registered. Each field is a
// *bool so that nil (absent from TOML) means "enabled by default", while an
// explicit false disables the runner without affecting others.
//
// The local runner also requires LocalModel.Endpoint to be set; setting
// Local = true without an endpoint has no effect.
type RunnersConfig struct {
	Claude    *bool `toml:"claude"`
	Gemini    *bool `toml:"gemini"`
	Local     *bool `toml:"local"`
	Container *bool `toml:"container"`
	// Anthropic gates the native provider.Provider-backed NativeRunner
	// registered under agent type "anthropic" (internal/provider/anthropic).
	// It is distinct from Claude, which gates the Docker/CLI-subprocess
	// ContainerRunner for agent type "claude" — the two are separate
	// execution paths (and separate budget buckets) even though both bill
	// the same Anthropic account. Also requires [providers.anthropic].api_key
	// to be set; Anthropic = true with no configured key has no effect.
	Anthropic *bool `toml:"anthropic"`
	// Google gates the native provider.Provider-backed NativeRunner
	// registered under agent type "google" (internal/provider/google). It is
	// distinct from Gemini, which gates the Docker/CLI-subprocess
	// ContainerRunner for agent type "gemini" — the two are separate
	// execution paths (and separate budget buckets), same reasoning as
	// Anthropic vs. Claude above. Also requires [providers.google].api_key to
	// be set; Google = true with no configured key has no effect.
	Google *bool `toml:"google"`
	// Groq, OpenRouter, and OpenAI gate NativeRunners registered under agent
	// types "groq"/"openrouter"/"openai", all backed by
	// internal/provider/openaicompat (they're OpenAI-wire-compatible, so no
	// dedicated adapter package is needed — see docs/api-keys-setup.md).
	// Each also requires the matching [providers.<name>].api_key to be set;
	// true with no configured key has no effect, same as Anthropic/Google.
	Groq       *bool `toml:"groq"`
	OpenRouter *bool `toml:"openrouter"`
	OpenAI     *bool `toml:"openai"`
}

func (r RunnersConfig) ClaudeEnabled() bool     { return r.Claude == nil || *r.Claude }
func (r RunnersConfig) GeminiEnabled() bool     { return r.Gemini == nil || *r.Gemini }
func (r RunnersConfig) LocalEnabled() bool      { return r.Local == nil || *r.Local }
func (r RunnersConfig) ContainerEnabled() bool  { return r.Container == nil || *r.Container }
func (r RunnersConfig) AnthropicEnabled() bool  { return r.Anthropic == nil || *r.Anthropic }
func (r RunnersConfig) GoogleEnabled() bool     { return r.Google == nil || *r.Google }
func (r RunnersConfig) GroqEnabled() bool       { return r.Groq == nil || *r.Groq }
func (r RunnersConfig) OpenRouterEnabled() bool { return r.OpenRouter == nil || *r.OpenRouter }
func (r RunnersConfig) OpenAIEnabled() bool     { return r.OpenAI == nil || *r.OpenAI }

// ProviderConfig configures a native (or OpenAI-compatible) LLM provider
// backend for the multi-provider harness — see docs/api-keys-setup.md. Phase
// 1 added this type so config had somewhere for it to land, without being
// read by runner construction. Phase 2 is the first consumer:
// [providers.anthropic] (APIKey + optional Endpoint/DefaultModel/
// TimeoutSeconds) wires internal/provider/anthropic.New into a NativeRunner
// registered under agent type "anthropic" — see internal/cli/serve.go and
// internal/cli/run.go. Keyed by provider name in the [providers.<name>] TOML
// table, e.g. [providers.groq], [providers.anthropic].
type ProviderConfig struct {
	Endpoint       string `toml:"endpoint"`
	APIKey         string `toml:"api_key"`
	DefaultModel   string `toml:"default_model"`
	TimeoutSeconds int    `toml:"timeout_seconds"`
}

type Config struct {
	DataDir          string `toml:"data_dir"`
	DBPath           string `toml:"-"`
	LogDir           string `toml:"-"`
	DropsDir         string `toml:"-"`
	SSHAuthSock      string `toml:"ssh_auth_sock"`
	ClaudeBinaryPath string `toml:"claude_binary_path"`
	GeminiBinaryPath string `toml:"gemini_binary_path"`
	ClaudeImage      string `toml:"claude_image"`
	GeminiImage      string `toml:"gemini_image"`
	// SandboxImage is the docker image used by sandbox.DockerSandbox (the
	// tool-execution sandbox for native-API-driven runners, e.g. the
	// "anthropic" NativeRunner) — distinct from ClaudeImage/GeminiImage,
	// which are for ContainerRunner's claude/gemini CLI-subprocess path.
	// Defaults to the same image (images/agent-base) since it already has
	// everything a generic git/bash sandbox needs; see
	// internal/sandbox/dockersandbox.go's package doc for the tradeoff.
	SandboxImage    string        `toml:"sandbox_image"`
	MaxConcurrent   int           `toml:"max_concurrent"`
	ShutdownTimeout time.Duration `toml:"shutdown_timeout"`
	DefaultTimeout  string        `toml:"default_timeout"`
	ServerAddr      string        `toml:"server_addr"`
	WebhookURL      string        `toml:"webhook_url"`
	WorkspaceRoot   string        `toml:"workspace_root"`
	WebhookSecret   string        `toml:"webhook_secret"`
	APIToken        string        `toml:"api_token"` // shared bearer for web UI + chatbot MCP; empty disables both auth and the chatbot MCP endpoint
	Projects        []Project     `toml:"projects"`
	VAPIDPublicKey  string        `toml:"vapid_public_key"`
	VAPIDPrivateKey string        `toml:"vapid_private_key"`
	VAPIDEmail      string        `toml:"vapid_email"`
	ClaudeConfigDir string        `toml:"claude_config_dir"`
	LocalModel      LocalModel    `toml:"local_model"`
	Runners         RunnersConfig `toml:"runners"`
	Budget          BudgetConfig  `toml:"budget"`
	// Scheduler configures internal/scheduler.Scheduler, the retry-then-
	// escalate loop for role-typed tasks. Started only by `serve` (the
	// one-shot `run` command has no background scheduler).
	Scheduler SchedulerConfig `toml:"scheduler"`
	// Providers configures native/OpenAI-compatible LLM backends by name (see
	// ProviderConfig). Unused by runner construction in Phase 1.
	Providers map[string]ProviderConfig `toml:"providers"`
	// ExternalBindAllowed must be explicitly true to bind a non-loopback address.
	ExternalBindAllowed bool `toml:"external_bind_allowed"`
}

// BudgetConfig configures rolling per-provider spend caps. With no providers
// set, budget gating is disabled.
type BudgetConfig struct {
	Window        string             `toml:"window"`
	Provider5hUSD map[string]float64 `toml:"provider_5h_usd"`
}

// SchedulerConfig configures internal/scheduler.Scheduler's poll loop.
type SchedulerConfig struct {
	// PollIntervalSeconds is how often the scheduler checks for role-typed
	// FAILED tasks to retry or escalate. Defaults to 30 when zero/unset.
	PollIntervalSeconds int `toml:"poll_interval_seconds"`
	// AskUserTimeoutSeconds is how long a role-typed task may sit BLOCKED on
	// an unanswered ask_user question before the scheduler resumes it itself
	// with a system-authored fallback answer (escalating to the next tier of
	// the role's ladder where possible) and flags it tasks.needs_review for
	// a human to double-check later. Defaults to 600 (10 minutes) when
	// zero/unset.
	AskUserTimeoutSeconds int `toml:"ask_user_timeout_seconds"`
}

// PollInterval returns the configured poll interval, defaulting to 30s.
func (c SchedulerConfig) PollInterval() time.Duration {
	if c.PollIntervalSeconds <= 0 {
		return 30 * time.Second
	}
	return time.Duration(c.PollIntervalSeconds) * time.Second
}

// AskUserTimeout returns the configured ask-user timeout, defaulting to 10
// minutes when zero/unset. Ten minutes is long enough that a human actively
// working alongside the agent (this is a self-hosted, typically
// single-operator system, not a large on-call team watching a queue) has a
// realistic chance to notice a clarification request and answer it, but
// short enough that a role-typed task doesn't sit stalled for hours — often
// the common case, not the exception, in this deployment shape — waiting on
// input that may never come.
func (c SchedulerConfig) AskUserTimeout() time.Duration {
	if c.AskUserTimeoutSeconds <= 0 {
		return 10 * time.Minute
	}
	return time.Duration(c.AskUserTimeoutSeconds) * time.Second
}

func Default() (*Config, error) {
	home, err := os.UserHomeDir()
	if err != nil {
		return nil, fmt.Errorf("cannot determine home directory: %w", err)
	}
	if home == "" {
		return nil, errors.New("cannot determine home directory: HOME is empty")
	}
	dataDir := filepath.Join(home, ".claudomator")
	return &Config{
		DataDir:          dataDir,
		DBPath:           filepath.Join(dataDir, "claudomator.db"),
		LogDir:           filepath.Join(dataDir, "executions"),
		DropsDir:         filepath.Join(dataDir, "drops"),
		SSHAuthSock:      os.Getenv("SSH_AUTH_SOCK"),
		ClaudeBinaryPath: "claude",
		GeminiBinaryPath: "gemini",
		ClaudeImage:      "claudomator-agent:latest",
		GeminiImage:      "claudomator-agent:latest",
		SandboxImage:     "claudomator-agent:latest",
		MaxConcurrent:    3,
		DefaultTimeout:   "15m",
		ServerAddr:       "127.0.0.1:8484",
		WorkspaceRoot:    "/workspace",
		ClaudeConfigDir:  "/workspace/claudomator/credentials/claude",
	}, nil
}

// LoadFile loads a TOML config file on top of the defaults.
// Fields not present in the file retain their default values.
func LoadFile(path string) (*Config, error) {
	cfg, err := Default()
	if err != nil {
		return nil, err
	}
	if _, err := toml.DecodeFile(path, cfg); err != nil {
		return nil, fmt.Errorf("loading config file %q: %w", path, err)
	}
	return cfg, nil
}

// EnsureDirs creates the data directory structure.
func (c *Config) EnsureDirs() error {
	for _, dir := range []string{c.DataDir, c.LogDir, c.DropsDir} {
		if err := os.MkdirAll(dir, 0700); err != nil {
			return err
		}
	}
	return nil
}