package automations

import (
	"context"
	"encoding/json"
	"fmt"
	"log/slog"
	"strings"

	"git.yeij.top/AskaEth/Cyrene_v2/internal/bus"
	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/model"
	"git.yeij.top/AskaEth/Cyrene_v2/pkg/plugins/sdk"
)

// Action is a unit of work executed when a schedule, event rule or reminder
// fires. Execute runs the action with the trigger payload and returns a result
// (or an error, wrapped with %w). Implementations must be safe for concurrent use
// because the engine may invoke them from multiple goroutines.
//
// The three concrete implementations are FuncAction (a plain function), ToolAction
// (an sdk.Tool) and AIAction (a prompt run through the AI pipeline).
type Action interface {
	// Name identifies the action in logs and in the published Result.
	Name() string
	// Execute runs the action with the trigger payload.
	Execute(ctx context.Context, payload any) (any, error)
}

// Func is a plain function action.
type Func func(ctx context.Context, payload any) (any, error)

// FuncAction adapts a plain function to the Action interface.
type FuncAction struct {
	name string
	fn   Func
}

// NewFuncAction wraps fn as a named action. It returns an error wrapping
// ErrNilAction when name is blank or fn is nil.
func NewFuncAction(name string, fn Func) (*FuncAction, error) {
	if strings.TrimSpace(name) == "" {
		return nil, fmt.Errorf("automations: func action: %w", ErrNilAction)
	}
	if fn == nil {
		return nil, fmt.Errorf("automations: func action %q: %w", name, ErrNilAction)
	}
	return &FuncAction{name: name, fn: fn}, nil
}

// Name returns the action name.
func (f *FuncAction) Name() string { return f.name }

// Execute runs the wrapped function with the payload.
func (f *FuncAction) Execute(ctx context.Context, payload any) (any, error) {
	return f.fn(ctx, payload)
}

// ToolAction adapts an sdk.Tool to the Action interface.
type ToolAction struct {
	Tool sdk.Tool
}

// NewToolAction wraps a registered tool as a named action. A nil tool returns an
// error wrapping ErrNilAction.
func NewToolAction(t sdk.Tool) (*ToolAction, error) {
	if t == nil {
		return nil, fmt.Errorf("automations: tool action: %w", ErrNilAction)
	}
	return &ToolAction{Tool: t}, nil
}

// Name returns the underlying tool's name.
func (t *ToolAction) Name() string { return t.Tool.Name() }

// Execute delegates to the underlying tool.
func (t *ToolAction) Execute(ctx context.Context, payload any) (any, error) {
	return t.Tool.Execute(ctx, payload)
}

// AIAction drives a prompt through the AI pipeline (loop or agent) and returns
// the generated text. sessionID scopes the conversation for tracing/persistence.
type AIAction struct {
	name      string
	prompt    string
	sessionID string
	pipeline  Pipeline
}

// NewAIAction builds a prompting action. name must be non-blank and p must be
// non-nil; otherwise an error wrapping ErrNilAction or ErrNoPipeline is returned.
func NewAIAction(name, prompt, sessionID string, p Pipeline) (*AIAction, error) {
	if strings.TrimSpace(name) == "" {
		return nil, fmt.Errorf("automations: ai action: %w", ErrNilAction)
	}
	if p == nil {
		return nil, fmt.Errorf("automations: ai action %q: %w", name, ErrNoPipeline)
	}
	return &AIAction{name: name, prompt: prompt, sessionID: sessionID, pipeline: p}, nil
}

// Name returns the action name.
func (a *AIAction) Name() string { return a.name }

// Execute runs the prompt (with the payload appended) through the pipeline and
// returns the generated text as the result.
func (a *AIAction) Execute(ctx context.Context, payload any) (any, error) {
	msgs := []model.Message{model.TextMessage(model.RoleUser, a.promptMessage(payload))}
	res, err := a.pipeline.Run(ctx, a.sessionID, msgs)
	if err != nil {
		return nil, fmt.Errorf("automations: ai action %q: %w", a.name, err)
	}
	return res.Text, nil
}

// promptMessage renders the prompt plus a readable form of the trigger payload.
func (a *AIAction) promptMessage(payload any) string {
	if payload == nil {
		return a.prompt
	}
	if s, ok := payload.(string); ok {
		return a.prompt + "\nTrigger payload: " + s
	}
	if b, err := json.Marshal(payload); err == nil {
		return a.prompt + "\nTrigger payload: " + string(b)
	}
	return a.prompt + "\nTrigger payload: " + fmt.Sprint(payload)
}

// runAction executes a with payload under the configured deadline and publishes
// the outcome to SubjectResult. It is the single place where automation execution
// and result reporting are wired, so every trigger kind reports consistently. A
// panic is recovered and recorded as a failed result so a misbehaving action
// cannot crash the calling goroutine.
func runAction(ctx context.Context, cfg Config, b bus.Bus, log *slog.Logger, kind, ruleID string, a Action, payload any) {
	if a == nil {
		return
	}
	execCtx := ctx
	if cfg.ActionTimeout > 0 {
		var cancel context.CancelFunc
		execCtx, cancel = context.WithTimeout(ctx, cfg.ActionTimeout)
		defer cancel()
	}

	out, err := executeSafely(execCtx, a, payload)
	res := Result{Kind: kind, RuleID: ruleID, Action: a.Name(), Payload: payload, Output: out}
	if err != nil {
		res.Error = err.Error()
		log.Error("automation action failed", "kind", kind, "rule_id", ruleID, "action", a.Name(), "err", err)
	} else {
		log.Info("automation action ran", "kind", kind, "rule_id", ruleID, "action", a.Name())
	}

	if cerr := b.Publish(ctx, SubjectResult, res); cerr != nil {
		log.Error("publish automation result", "kind", kind, "rule_id", ruleID, "err", cerr)
	}
}

// executeSafely runs a.Execute, converting a panic into an error so the action
// reports a failed result instead of crashing the engine goroutine.
func executeSafely(ctx context.Context, a Action, payload any) (out any, err error) {
	defer func() {
		if r := recover(); r != nil {
			out = nil
			err = fmt.Errorf("automations: action %q panicked: %v", a.Name(), r)
		}
	}()
	return a.Execute(ctx, payload)
}