package config

import (
	"fmt"
)

// Config is the full harness.toml surface. Defaults live in Default();
// apply() overlays the parsed document; Validate() enforces invariants.
type Config struct {
	Vertical  string
	WorkRoot  string
	ReportDir string
	Loop      LoopConfig
	Redmine   RedmineConfig
	LiteLLM   LiteLLMConfig
	Models    ModelsConfig
	Bash      BashConfig
	Demo      DemoConfig
}

type LoopConfig struct {
	MaxRounds int
}

type RedmineConfig struct {
	URL          string
	KeyRef       string
	ScopeQuery   string
	ScopeQueryID int
	ClassField   string
	DefaultClass string
	Limit        int
}

type LiteLLMConfig struct {
	BaseURL     string
	KeyRef      string
	TimeoutSecs int
	MaxRetries  int
}

type ModelsConfig struct {
	// Tiers maps tier aliases (mopac-study, ...) to concrete proxy models.
	Tiers map[string]string
	// Classes maps task classes (study, code, ...) to tier aliases.
	Classes map[string]string
	// DefaultTier is used when a task carries no class.
	DefaultTier string
}

type BashConfig struct {
	Enabled        bool
	Allow          []string
	Deny           []string
	DefaultAllow   bool
	TimeoutSecs    int
	MaxOutputBytes int
}

type DemoConfig struct {
	ID      string
	Subject string
	Prompt  string
	Class   string
}

// Default returns the built-in defaults for every field.
func Default() *Config {
	return &Config{
		WorkRoot:  ".",
		ReportDir: "reports",
		Loop:      LoopConfig{MaxRounds: 8},
		Redmine: RedmineConfig{
			ClassField:   "Class",
			DefaultClass: "primary",
			Limit:        50,
		},
		LiteLLM: LiteLLMConfig{TimeoutSecs: 120, MaxRetries: 2},
		Models: ModelsConfig{
			Tiers:       map[string]string{},
			Classes:     map[string]string{},
			DefaultTier: "mopac-primary",
		},
		Bash: BashConfig{Enabled: true, TimeoutSecs: 60, MaxOutputBytes: 100_000},
		Demo: DemoConfig{
			ID:      "demo-1",
			Subject: "MVP demo: GLM self-description",
			Prompt:  "tell me about yourself",
			Class:   "primary",
		},
	}
}

func (c *Config) apply(doc TOMLDoc) error {
	if v, ok := doc.String("vertical"); ok {
		c.Vertical = v
	}
	if v, ok := doc.String("work_root"); ok {
		c.WorkRoot = v
	}
	if v, ok := doc.String("report_dir"); ok {
		c.ReportDir = v
	}
	if v, ok := doc.Table("loop").Int("max_rounds"); ok {
		c.Loop.MaxRounds = int(v)
	}

	rm := doc.Table("redmine")
	if v, ok := rm.String("url"); ok {
		c.Redmine.URL = v
	}
	if v, ok := rm.String("key_ref"); ok {
		c.Redmine.KeyRef = v
	}
	if v, ok := rm.String("scope_query"); ok {
		c.Redmine.ScopeQuery = v
	}
	if v, ok := rm.Int("scope_query_id"); ok {
		c.Redmine.ScopeQueryID = int(v)
	}
	if v, ok := rm.String("class_field"); ok {
		c.Redmine.ClassField = v
	}
	if v, ok := rm.String("default_class"); ok {
		c.Redmine.DefaultClass = v
	}
	if v, ok := rm.Int("limit"); ok {
		c.Redmine.Limit = int(v)
	}

	lt := doc.Table("litellm")
	if v, ok := lt.String("base_url"); ok {
		c.LiteLLM.BaseURL = v
	}
	if v, ok := lt.String("key_ref"); ok {
		c.LiteLLM.KeyRef = v
	}
	if v, ok := lt.Int("timeout_secs"); ok {
		c.LiteLLM.TimeoutSecs = int(v)
	}
	if v, ok := lt.Int("max_retries"); ok {
		c.LiteLLM.MaxRetries = int(v)
	}

	md := doc.Table("models")
	for _, k := range md.Keys() {
		if k == "default_tier" {
			continue
		}
		if v, ok := md.String(k); ok {
			c.Models.Tiers[k] = v
		}
	}
	if v, ok := md.String("default_tier"); ok {
		c.Models.DefaultTier = v
	}
	cls := doc.Table("models", "classes")
	for _, k := range cls.Keys() {
		if v, ok := cls.String(k); ok {
			c.Models.Classes[k] = v
		}
	}

	bt := doc.Table("tools", "bash")
	if v, ok := bt.Bool("enabled"); ok {
		c.Bash.Enabled = v
	}
	if v, ok := bt.StringList("allow"); ok {
		c.Bash.Allow = v
	}
	if v, ok := bt.StringList("deny"); ok {
		c.Bash.Deny = v
	}
	if v, ok := bt.String("default"); ok {
		switch v {
		case "allow":
			c.Bash.DefaultAllow = true
		case "deny":
			c.Bash.DefaultAllow = false
		default:
			return fmt.Errorf("[tools.bash]: default must be \"allow\" or \"deny\", got %q", v)
		}
	}
	if v, ok := bt.Int("timeout_secs"); ok {
		c.Bash.TimeoutSecs = int(v)
	}
	if v, ok := bt.Int("max_output_bytes"); ok {
		c.Bash.MaxOutputBytes = int(v)
	}

	dm := doc.Table("demo")
	if v, ok := dm.String("id"); ok {
		c.Demo.ID = v
	}
	if v, ok := dm.String("subject"); ok {
		c.Demo.Subject = v
	}
	if v, ok := dm.String("prompt"); ok {
		c.Demo.Prompt = v
	}
	if v, ok := dm.String("class"); ok {
		c.Demo.Class = v
	}
	return nil
}

// Validate enforces the invariants the conductor relies on.
func (c *Config) Validate() error {
	if c.Vertical == "" {
		return fmt.Errorf("[core]: vertical is required")
	}
	if c.Loop.MaxRounds < 1 {
		return fmt.Errorf("[loop]: max_rounds must be >= 1")
	}
	if c.LiteLLM.BaseURL == "" {
		return fmt.Errorf("[litellm]: base_url is required")
	}
	if c.LiteLLM.KeyRef == "" {
		return fmt.Errorf("[litellm]: key_ref is required (env:NAME, file:PATH, or literal:VALUE)")
	}
	if err := CheckKeyRef(c.LiteLLM.KeyRef); err != nil {
		return fmt.Errorf("[litellm]: %w", err)
	}
	if c.LiteLLM.TimeoutSecs < 1 || c.LiteLLM.MaxRetries < 0 {
		return fmt.Errorf("[litellm]: bad timeout_secs/max_retries")
	}

	// Redmine is optional (demo-only configs); if any piece is set, the rest
	// of the minimum set must be too.
	rc := c.Redmine
	if rc.URL != "" || rc.KeyRef != "" || rc.ScopeQuery != "" || rc.ScopeQueryID != 0 {
		if rc.URL == "" {
			return fmt.Errorf("[redmine]: url is required when redmine is configured")
		}
		if rc.KeyRef == "" {
			return fmt.Errorf("[redmine]: key_ref is required when redmine is configured")
		}
		if err := CheckKeyRef(rc.KeyRef); err != nil {
			return fmt.Errorf("[redmine]: %w", err)
		}
		if rc.ScopeQuery == "" && rc.ScopeQueryID == 0 {
			return fmt.Errorf("[redmine]: scope_query or scope_query_id is required")
		}
	}

	if len(c.Models.Tiers) == 0 {
		return fmt.Errorf("[models]: at least one tier alias is required")
	}
	if _, ok := c.Models.Tiers[c.Models.DefaultTier]; !ok {
		return fmt.Errorf("[models]: default_tier %q has no entry in [models]", c.Models.DefaultTier)
	}
	for class, tier := range c.Models.Classes {
		if _, ok := c.Models.Tiers[tier]; !ok {
			return fmt.Errorf("[models.classes]: class %q points at unknown tier %q", class, tier)
		}
	}

	if c.Bash.TimeoutSecs < 1 || c.Bash.MaxOutputBytes < 1 {
		return fmt.Errorf("[tools.bash]: bad timeout_secs/max_output_bytes")
	}
	if c.Demo.Prompt == "" {
		return fmt.Errorf("[demo]: prompt is required")
	}
	return nil
}