package gollama

import (
	"encoding/json"
	"time"

	"github.com/ollama/ollama/api"
)

// CallOption configures a single completion or chat request.
type CallOption func(*callConfig)

type callConfig struct {
	model      string
	opts       OptionSet
	system     string
	raw        bool
	keepAlive  *api.Duration
	think      *api.ThinkValue
	format     json.RawMessage
	truncate   *bool
	shift      *bool
	stream     *bool
}

func (c *Client) mergeCallConfig(callOpts ...CallOption) (*callConfig, error) {
	cfg := &callConfig{opts: c.defaultOpts}
	for _, opt := range callOpts {
		opt(cfg)
	}
	model, err := c.resolveModel(cfg.model)
	if err != nil {
		return nil, err
	}
	cfg.model = model
	return cfg, nil
}

func (cfg *callConfig) optionsMap() (map[string]any, error) {
	return cfg.opts.toMap()
}

func boolPtr(v bool) *bool { return &v }

// WithModel sets the model for a single call.
func WithModel(name string) CallOption {
	return func(c *callConfig) { c.model = name }
}

// WithOptions merges per-call generation options.
func WithOptions(opts OptionSet) CallOption {
	return func(c *callConfig) { c.opts = c.opts.Merge(opts) }
}

// WithSystem sets a system prompt for the call.
func WithSystem(system string) CallOption {
	return func(c *callConfig) { c.system = system }
}

// WithKeepAlive controls how long the model stays loaded after the request.
func WithKeepAlive(d time.Duration) CallOption {
	return func(c *callConfig) {
		c.keepAlive = &api.Duration{Duration: d}
	}
}

// WithThink enables thinking/reasoning for supported models.
func WithThink(enabled bool) CallOption {
	return func(c *callConfig) {
		c.think = &api.ThinkValue{Value: enabled}
	}
}

// WithThinkLevel sets thinking level ("high", "medium", "low", "max").
func WithThinkLevel(level string) CallOption {
	return func(c *callConfig) {
		c.think = &api.ThinkValue{Value: level}
	}
}

// WithFormatJSON requests JSON output format.
func WithFormatJSON() CallOption {
	return func(c *callConfig) { c.format = json.RawMessage(`"json"`) }
}

// WithFormatSchema requests structured output matching a JSON schema.
func WithFormatSchema(schema any) CallOption {
	return func(c *callConfig) {
		b, err := json.Marshal(schema)
		if err == nil {
			c.format = b
		}
	}
}

// WithTruncate truncates chat history when context is exceeded.
func WithTruncate(enabled bool) CallOption {
	return func(c *callConfig) { c.truncate = &enabled }
}

// WithShift shifts chat history when context is exceeded.
func WithShift(enabled bool) CallOption {
	return func(c *callConfig) { c.shift = &enabled }
}